OCCUPATIONAL HEALTH GUIDELINES
FOR THE MANAGEMENT OF
LOW BACK PAIN AT WORK

Evidence Review and Recommendations

Published March 2000

 

SUGGESTED CITATIONS

Carter JT, Birrell LN (Editors) 2000. Occupational health guidelines for the management of low back pain at work - principal recommendations. Faculty of Occupational Medicine. London.

Occupational health guidelines for the management of low back pain at work - leaflet for practitioners. Faculty of Occupational Medicine. London. 2000. Waddell G, Burton AK 2000.

Occupational health guidelines for the management of low back pain at work - evidence review. Faculty of Occupational Medicine. London.

Proposed review date: December 2005


 

ACKNOWLEDGEMENTS

Thanks are due to the following who made major contributions to preparing these guidelines:

- The Working Group and Reviewers (see page ii).
- The Steering Group and Funders, in particular Mr Brian Kazer of Blue Circle Industries plc and Mr Alan Bayley of British Occupational Health Research Foundation.
- The Royal College of General Practitioners for leading the way with their guidance and for permission to include their clinical guidelines as an appendix.
- Relevant Government Departments (Health and Social Security) and the Health and Safety Executive by providing assessors to the Working Group and supporting the initiative.
- Frances Quinn and Jananne Rahman of the Faculty of Occupational Medicine for preparing this document for publication.

 

MEMBERS OF THE FACULTY WORKING GROUP

Dr Tim Carter (Chairman) Occupational Physician
Professor Gordon Waddell (Reviewer) Orthopaedic Surgeon
Professor Kim Burton (Reviewer) Ergonomist
Dr Lisa Birrell (Scientific Secretary) Occupational Physician
Dr Cathy Amos Occupational Physician
Richard Bolton Physiotherapist
Dr John Gration Occupational Physician
Andrew Nicoll Occupational Health Nurse Manager, representing Royal College of Nursing
Dr Keith Palmer Occupational Physician
Dr Sally Randall Occupational Physician
Dr Charles Sears General Practitioner, representing Royal College of General Practitioners
Allason Thompson Physiotherapist
Claudia Treasure Physiotherapist representing the TUC
Dr Peter Verow Occupational Physician Assessors
Dr Andrew Auty Scientific Adviser, British Occupational Health Research Foundation
Avril Imison Head of Policy, Therapy Services, Department of Health
Dr Philip Sawney Medical Policy Manager, Department of Social Security
Dr David Snashall Occupational Physician, Health and Safety Executive

 

CONTENTS

1 Preface
2 Introduction
3 Principal recommendations for occupational health management

Figure 1 Diagnostic Triage including 'Red Flags'
Figure 2 Psychosocial Risk Factors - 'Yellow Flags' Figure
3 Active Rehabilitation Programme
4 Practitioners' leaflet - 'Occupational Health Guidelines for the Management of Low Back Pain at Work'
5 Evidence review methods

6 Evidence review
A Background
B Pre-placement assessment
C Prevention
D Assessment of the worker presenting with back pain
E Management principles for the worker presenting with back pain
F Management of the worker having difficulty returning to normal occupational duties at approximately 4-12 weeks
7 Evidence tables
Table 1a Systematic reviews
Table 1b Main conclusions of systematic reviews
Table 2 Narrative reviews
Table 3 Individual scientific studies
Table 4 Additional studies on return to work
Table 5 Previous guidelines
8 References
Appendix 1 Faculty of Occupational Medicine
Appendix 2 Clinical Guidelines for the Management of Acute Low Back Pain - Royal College of General Practitioners 1999


 

1 PREFACE

Disability from back pain in people of working age is one of the most dramatic failures of health care in recent years. Its greatest impact is on the lives of those affected and their families. However, it also has a major effect on industry through absenteeism and avoidable costs (the CBI estimate that back pain costs £208 for every employee each year) and at any one time 430,000 people in UK are receiving various social security benefits primarily for back pain.

This review and the guidelines based on it aim to reduce the toll of harm by providing a new approach to back pain management at work which is based on the best available scientific evidence and uses this to make practical recommendations on how to tackle the occupational health aspects of the problem. This project was made possible thanks to the foresight of Blue Circle Industries PLC who funded it as their 1999 Community Project. Completion of the project was only achieved because of the quality of the reviewers, the hard work of the multidisciplinary working group in the Faculty of Occupational Medicine and the logistical support provided by the British Occupational Health Research Foundation.

Evidence-based guidelines are becoming the benchmarks for practice in most areas of health care. It is hoped that this will be the first of many for UK occupational health practitioners. It complements existing guidelines produced for primary care health professionals by the Royal College of General Practitioners (RCGP) and thus should facilitate better links between the workplace and the community for back pain management.

The process used to prepare such guidelines is well established (Royal College of General Practitioners 1995). Six key occupational health areas were identified and a systematic review prepared of the scientific evidence covering each of these areas. Evidence statements were prepared and linked to that evidence. As far as possible, recommendations for practice were based upon and linked to these evidence statements, though there are some important areas where there is a lack of evidence. The evidence and recommendations concentrate on interventions and outcomes rather than on professional disciplines and so do not make any comment on which occupational health professional should provide advice or support. A number of evidence gaps in occupational health management of low back pain are identified. The need to fill these gaps in knowledge is the first of several challenges posed by the review. Revisions of the review and guidelines are envisaged to take account of new information.

Other challenges include:
- The need for everyone to recognise that work is only one contributor to back pain but that back pain whatever its cause can, if poorly managed, have a devastating effect on a person's ability to work.
- The importance of planning ahead at the workplace to reduce back pain disability by following the guidelines and involving all those concerned - because it can be difficult to manage a case well if the ground has not been laid in advance.
- How best to encourage General Practitioners to follow the RCGP guidelines, for instance by offers of collaboration from the workplace to maintain people with back pain at work or to help them to return to work as soon as possible if they have been absent.
- The need for the health care system to develop the sort of rehabilitation measures which have been shown to be effective in other countries and to make them available within a month of the start of an episode of back pain and before it has become a chronic and largely irremediable problem.

Tim Carter and Lisa Birrell
Chair and Secretary of Faculty of Occupational Medicine Guidelines Working Group
Editors of Chapters 1- 4


 

2 INTRODUCTION

This publication presents the output from the Blue Circle Industries PLC/Faculty of Occupational Medicine/British Occupational Health Research Foundation project on occupational health aspects of low back pain:

1. a systematic review comprising the scientific evidence base underlying the Occupational Health Guidelines for the Management of Low Back Pain at Work. This provides a directory and guide to the evidence available, and links it to individual evidence statements. (Chapter 5 onwards)

2. Occupational Health Guidelines for the Management of Low Back Pain at Word: the full evidence statements and recommendations based on them for occupational health practitioners. (Chapter 3)

3. a leaflet summarising the evidence based guidelines for occupational health practitioners. (Chapter 4)

The complementary RCGP Clinical Guidelines for the Management of Acute Low Back Pain (1999) are included as an appendix. (Appendix 2)

The development process for the guidelines began with the Faculty of Occupational Medicine (FOM) commissioning a comprehensive review of the available scientific literature, from which a guideline document was developed. Wherever practicable, the methods of guideline development described by the RCGP Clinical Guidelines Development Group were adopted (Royal College of General Practitioners 1995).

The Guidelines consist of recommendations accompanied by evidence statements, with ratings of the strength of that evidence. The Evidence Review expands on the evidence statements, references the associated literature and specifically links the evidence statements to the recommendations given in the Guidelines.

The Evidence Review was written principally by the appointed reviewers, whilst the Guidelines and leaflets resulted from extensive debate by a multidisciplinary development group assembled for this purpose by the FOM.

This intensive development process would not have been possible without the support of the British Occupational Health Research Foundation (BOHRF) and funding from Blue Circle Industries PLC (BCI).

Scope
The Guidelines are intended for health professionals undertaking the occupational health management of low back pain (LBP). They focus on interventions that might be considered appropriate for occupational health practitioners to implement. They are designed to complement and to be used in conjunction with the RCGP Clinical Guidelines for the Management of Acute Low Back Pain (Royal College of General Practitioners 1999).

It is not intended, nor should it be taken to imply, that these guidelines override existing legal obligations. Any duties under the Health and Safety at Work Act 1974, the Management of Health and Safety at Work Regulations 1992, the Manual Handling Operations Regulations 1992, the Disability Discrimination Act 1995, or other relevant legislation must be given due consideration.

 

3 PRINCIPAL RECOMMENDATIONS FOR OCCUPATIONAL HEALTH MANAGEMENT

This section lists the full evidence statements derived from the systematic literature review. Recommendations for occupational health management based on each set of statements are given alongside. Recommendations are also included which are not strictly evidence-based, but considered good practice either legally or by consensus, and these are identified by the use of italics.

The recommendations linked to evidence statements are grouped according to occupational health context:
A. Background
B. Pre-placement assessment
C. Prevention
D. Assessment of the worker presenting with back pain
E. Management principles for the worker presenting with back pain
F. Management of the worker having difficulty returning to normal occupational duties at approximately 4-12 weeks

The strength of evidence for each statement is classified as follows:
*** Strong evidence - provided by generally consistent findings in multiple, high quality scientific studies.
** Moderate evidence - provided by generally consistent findings in fewer, smaller or lower quality scientific studies.
* Limited or contradictory evidence - provided by one scientific study or inconsistent findings in multiple scientific studies.
- No scientific evidence - based on clinical studies, theoretical considerations and/or clinical consensus.

Notes:
1. 'LBP' within these guidelines means non-specific low back pain, unless stated otherwise.
2. 'Worker' is used to describe all those in employment (including the self-employed, trainees and apprentices).
3. 'Employer' is used as a collective term for all those with managerial responsibilities, including all types of employers, line managers, supervisors and their representatives.

A Background

Recommendation Evidence
You, as an occupational health practitioner, have a professional duty to support the worker with LBP and should do so whether or not occupational factors play any role in causation.

Make employers and workers aware that:

- LBP is common and frequently recurrent but acute attacks are usually brief and self-limiting.

- Physical demands at work are one factor influencing LBP but are often not the most important.

- Prevention and case management need to be directed at both physical and psychosocial factors.

 

 

 

 

 

 

 

Establish a partnership, involving workers, employers and health professionals in the workplace and the community, with a common consistent approach to agreed goals, to manage back pain and prevent unnecessary disability.

*** Most adults (60-80%) experience LBP at some time and it is often persistent or recurrent. It is one of the most common reasons for seeking health care and it is now one of the commonest health reasons given for work loss.

*** Physical demands of work (manual materials handling, lifting, bending, twisting, and whole body vibration) can be associated with increased reports of back symptoms, aggravation of symptoms and 'injuries'.

* There is limited and contradictory evidence that the length of exposure to physical stressors at work (cumulative risk) increases reports of back symptoms or of persistent symptoms.

*** Physical demands of work (manual materials handling, lifting, bending, twisting, and whole body vibration) are a risk factor for the incidence (onset) of LBP, but overall it appears that the size of the effect is less than that of other individual, non-occupational and unidentified factors.

** Physical demands of work play only a minor role in the development of disc degeneration.

*** Care-seeking and disability due to LBP depend more on complex individual and work-related psychosocial factors than on clinical features or physical demands of work.

B Pre-placement assessment

Recommendation Evidence
LBP is common and recurrent and is not a reason for denying employment in most circumstances. However care should be taken when placing individuals with a strong history of LBP in physically demanding jobs.

Enquire about previous history of LBP as part of the pre-placement assessment, in particular the frequency and duration of attacks, time since last attack, radiating leg pain, previous surgery and sickness absence due to LBP.

Do not routinely include clinical examination of the back, lumbar x-rays, back function testing, general fitness or psychosocial factors in the pre-placement assessment.

 

 

 

 

 

 

 

Placement should take account of the risk assessment and requirements under the Disability Discrimination Act 1995 to provide 'suitable and reasonable' adjustments, but it is ultimately a question of professional judgement.

*** The single, most consistent predictor of future LBP and work loss is a previous history of LBP, including in particular the frequency and duration of attacks, time since last attack, radiating leg pain, previous surgery and sickness absence due to LBP.

** Examination findings, including in particular height, weight, lumbar flexibility and straight leg raising (SLR), have little predictive value for future LBP or disability.

** The level of general (cardio-respiratory) fitness has no predictive value for future LBP.

* There is limited and contradictory evidence that attempting to match physical capability to job demands may reduce future LBP and work loss.

*** X-ray and MRI findings have no predictive value for future LBP or disability.

*** Back-function testing machines (isometric, isokinetic or isoinertial measurements) have no predictive value for future LBP or disability.

*** For symptom-free people, individual psychosocial findings are a risk factor for the incidence (onset) of LBP, but overall the size of the effect is small.

C Prevention

Recommendation Evidence
Advise on current good working practices such as specified in the Manual Handling Regulations and associated guidance.

Do not recommend lumbar belts and supports or traditional biomedical education as methods of preventing LBP. There is insufficient evidence to advocate general exercise or physical fitness programmes.

 

 

 

 

 

Advise employers that high job satisfaction and good industrial relations are the most important organisational characteristics associated with low disability and sickness absence rates attributed to LBP.

Encourage employers to:
- Consider joint employer-worker initiatives to identify and control occupational risk factors.
- Monitor back problems and sickness absence due to LBP.
- Improve safety and develop a 'safety culture'.

 




 

* There is contradictory evidence that various general exercise/physical fitness programmes may reduce future LBP and work loss; any effect size appears to be modest.

*** Traditional biomedical education based on an injury model does not reduce future LBP and work loss. - There is preliminary evidence that educational interventions which specifically address beliefs and attitudes may reduce future work loss due to LBP.

*** Lumbar belts or supports do not reduce work-related LBP and work loss.

*** Low job satisfaction and unsatisfactory psychosocial aspects of work are risk factors for reported LBP, health care use and work loss, but the size of that association is modest.

 

 

* There is limited evidence but general consensus that joint employer-worker initiatives (generally involving organisational culture and high stakeholder commitment to identify and control occupational risk factors and improve safety, surveillance measures and 'safety culture') can reduce the number of reported back 'injuries' and sickness absences, but there is no clear evidence on the optimum strategies and inconsistent evidence on the effect size.

 


D Assessment of the worker presenting with back pain

Recommendation Evidence
Screen for serious spinal diseases and nerve root problems (see 'Diagnostic Triage' Figure 1).

Clinical examination may aid clinical management (RCGP 1999), but is of limited value in planning occupational health management or in predicting the vocational outcome.

Take a clinical, disability and occupational history, concentrating on the impact of symptoms on activity and work, and any obstacles to recovery and return to work.

 

 




Consider psychosocial 'yellow flags' to identify workers at particular risk of developing chronic pain and disability (Figure 2). Use this assessment to instigate active case management at an early stage.

 

X-rays and scans are not indicated for the occupational health management of the patient with LBP.

 

Ensure that any incident of LBP which may be work-related is investigated and advice given on remedial action. If appropriate, review the risk assessment.

** Screening for 'red flags' and diagnostic triage is important to exclude serious spinal diseases and nerve root problems.

** Examination findings, including in particular height, weight, lumbar flexibility and SLR are of limited value in planning occupational health management or in predicting the prognosis of non-specific LBP.

** Patients who are older (particularly >50 years), have more prolonged and severe symptoms, have radiating leg pain, whose symptoms impact more on activity and work, and who have responded less well to previous therapy are likely to have slower clinical progress, poorer response to treatment and rehabilitation, and more risk of long term disability.






*** Individual and work-related psychosocial factors play an important role in persisting symptoms and disability, and influence response to treatment and rehabilitation. Screening for 'yellow flags' can help to identify those workers with LBP who are at risk of developing chronic pain and disability. Workers' own beliefs that their LBP was caused by their work and their own expectations about inability to return to work are particularly important.

*** In patients with non-specific LBP, x-ray and MRI findings do not correlate with clinical symptoms or work capacity.

 

 


E Management principles for the worker presenting with back pain

Recommendation Evidence
Clinical:
 
Clinical management should follow the RCGP (1999) guidelines. Discuss expected recovery times, and the importance of continuing ordinary activities as normally as possible despite pain.

 

 

Ensure that workers with LBP receive the key information in a form they understand (see footnote The Back Book).

*** Advice to continue ordinary activities of daily living as normally as possible despite the pain can give equivalent or faster symptomatic recovery from the acute symptoms, and leads to shorter periods of work loss, fewer recurrences and less work loss over the following year than 'traditional' medical treatment (advice to rest and 'let pain be your guide' for return to normal activity).

** The above advice can be usefully supplemented by simple educational interventions specifically designed to overcome fear avoidance beliefs and encourage patients to take responsibility for their own self-care.

Occupational:
 
Encourage the worker to remain in his or her job, or to return at an early stage, even if there is still some LBP- do not wait until they are completely pain-free. Consider the following steps to facilitate this:

- Initiate communication with their primary health care professional early in treatment and rehabilitation.

- Advise the worker to continue as normally as possible and provide support to achieve this.

- Advise employers on the actions required, which may include maintaining sympathetic contact with the absent worker.

- Consider temporary adaptations of the job or pattern of work.

 

 

 

 

** Communication, co-operation and common agreed goals between the worker with LBP, the occupational health team, supervisors, management and primary health care professionals is fundamental for improvement in clinical and occupational health management and outcomes.

*** Most workers with LBP are able to continue working or to return to work within a few days or weeks, even if they still have some residual or recurrent symptoms, and they do not need to wait till they are completely pain free.

* Advice to continue ordinary activities as normally as possible, in principle, applies equally to work. The scientific evidence confirms that this general approach leads to shorter periods of work loss, fewer recurrences and less work loss over the following year, although most of the evidence comes from intervention packages and the clinical evidence focusing solely on advice about work is limited. *

There is general consensus but limited scientific evidence that workplace organisational and/or management strategies (generally involving organisational culture and high stakeholder commitment to improve safety, provide optimum case management and encourage and support early return to work) may reduce absenteeism and duration of work loss

 

Footnote: The Back Book is an evidence-based booklet developed in conjunction with the RCGP clinical guidelines, for use by patients and published by The Stationery Office.


F Management of the worker having difficulty returning to normal occupational duties at approximately 4-12 weeks

Recommendation Evidence
Ensure that workers, employers and primary care health professionals understand that the longer anyone is off work with LBP, the greater the risk of chronic pain and disability, and the lower their chances of ever returning to work.

Address the common misconception among workers and employers of the need to be pain-free before return to work. Some pain is to be expected and the early resumption of work activity improves the prognosis.

Encourage the employer to establish a surveillance system to identify those off work with LBP for over 4 weeks so that appropriate action can be taken. Intervention at this stage is more effective than delaying and having to deal with established intractable chronic pain and disability.

Advise employers on ways in which the physical demands of the job can be temporarily modified to facilitate return to work.

 





If medical treatment fails to produce recovery and return to work by 4-12 weeks, communicate and collaborate with primary health care professionals to shift the emphasis from dependence on symptomatic treatment to rehabilitation and self-management strategies.

 

Where practicable, refer the worker who is having difficulty returning to normal occupational duties at 4-12 weeks to an active rehabilitation programme. Such a rehabilitation programme needs to be carefully designed to fit local circumstances and should consist of a multidisciplinary 'package' of interventions (Figure 3).





 

 

*** The longer a worker is off work with LBP, the lower their chances of ever returning to work. Once a worker is off work for 4-12 weeks they have a 10-40% risk (depending on the setting) of still being off work at one year; after 1-2 years absence it is unlikely they will return to any form of work in the foreseeable future, irrespective of further treatment.

 


*** Various treatments for chronic LBP may produce some clinical improvement, but most clinical interventions are quite ineffective at returning people to work once they have been off work for a protracted period with LBP.



** From an organisational perspective, the temporary provision of lighter or modified duties facilitates return to work and reduces time off work.

- Conversely, there is some suggestion that clinical advice to return only to restricted duties may act as a barrier to return to normal work, particularly if no lighter or modified duties are available.



** Changing the focus from purely symptomatic treatment to an 'active rehabilitation programme' can produce faster return to work, less chronic disability and less sickness absence. There is no clear evidence on the optimum content or intensity of such packages, but there is generally consistent evidence on certain basic elements. Such interventions are more effective in an occupational setting than in a health care setting.

** A combination of optimum clinical management, a rehabilitation programme, and organisational interventions designed to assist the worker with LBP return to work, is more effective than single elements alone.

 





 

 



Figure 1: Diagnostic Triage including 'Red Flags'

SIMPLE BACK PAIN
Presentation between ages 20-55
Lumbosacral region, buttocks and thighs
Pain 'mechanical' in nature - Varies with physical activity and time
Patient well
Prognosis good - 90% recover from acute attack within six weeks

NERVE ROOT PAIN
Unilateral leg pain worse than low back pain
Pain generally radiates to foot or toes
Numbness or paraesthesia in same distribution
Nerve irritation signs - Reduced SLR which reproduces leg pain
Motor, sensory or reflex change - Limited to one nerve root
Prognosis reasonable - 50% recover from acute attack within six weeks
RED FLAGS FOR POSSIBLE SERIOUS SPINAL PATHOLOGY
Age of onset less than 20 or greater than 55 years
Violent trauma: eg. fall from a height, RTA
Constant, progressive, non-mechanical pain
Thoracic pain
PMH carcinoma, systemic steroids, drug abuse, HIV
Systemically unwell, weight loss
Persisting severe restriction of lumbar flexion
Widespread neurology
Structural deformity


Reproduced from: Clinical Guidelines for the Management of Acute Low Back Pain - Royal College of General Practitioners 1999

Figure 2: Psychosocial Risk Factors - 'Yellow Flags'

When conducting an assessment, it may be useful to consider psychosocial 'yellow flags' (beliefs and behaviours on the part of the patient which may predict poor outcomes).

The following factors are important and consistently predict poor outcomes:
=> A belief that back pain is harmful or potentially severely disabling
=> Fear-avoidance behaviour (avoiding a movement or activity due to misplaced anticipation of pain) and reduced activity levels
=> Tendency to low mood and withdrawal from social interaction
=> Expectation of passive treatment(s) rather than a belief that active participation will help

Suggested questions to the worker with low back pain (to be phrased in your own style):
=> Have you had time off work in the past with back pain?
=> What do you understand is the cause of your back pain?
=> What are you expecting will help you?
=> How is your employer responding to your back pain? Your co-workers? Your family?
=> What are you doing to cope with your back pain?
=> Do you think you will return to work? When?

A worker may considered to be 'at risk' if:
=> There is a cluster of a few very salient factors
=> There is a group of several less important factors that combine cumulatively

The presence of risk factors should alert the clinician to the possibility of long-term problems and the need to prevent their development. Specialised psychological referrals should only be required for those with psychopathology, or for those who fail to respond to the management advocated in this guideline.


Reproduced from: Kendall et al. 1997


Figure 3: Active Rehabilitation Programme

Education:
Directed primarily at overcoming fear avoidance beliefs and encouraging patients to learn to manage and take responsibility for their own self-care (for example The Back Book).

Reassurance and advice:
Strong reassurance and advice to stay active.

Exercise:
An active, progressive exercise and physical fitness programme.

Pain management:
Behavioural principles of pain management

Work:
In an occupational setting and directed strongly towards return to work.

Rehabilitation:
May also include some symptomatic relief measures, but if so these should supplement and reinforce, and must not interfere with the primary goal of rehabilitation.

Footnote: The Back Book is an evidence-based booklet developed in conjunction with the RCGP clinical guidelines, for use by patients and published by The Stationery Office.

 

4 PRACTITIONERS' LEAFLET-'OCCUPATIONAL HEALTH GUIDELINES FOR THE MANAGEMENT OF LOW BACK PAIN AT WORK'

These guidelines represent the main recommendations and evidence statements derived from a detailed Evidence Review and developed by a multidisciplinary group of practitioners. They concern the clinical management of workers affected by non-specific low back pain (LBP), including advice on placement, rehabilitation and measures for prevention. They focus on actions to be taken to assist the individual and do not specifically cover legal issues, health and safety management, job design and ergonomics. They assume that a risk assessment has been conducted and used to define the control measures required, including the need for occupational health advice.


The evidence is weighted as follows:
*** Strong evidence - generally consistent findings in multiple, high quality scientific studies.
** Moderate evidence - generally consistent findings in fewer, smaller or lower quality scientific studies.
* Limited or contradictory evidence
- one scientific study or inconsistent findings in multiple scientific studies.


These guidelines complement and should be used in conjunction with the RCGP Clinical Guidelines for the Management of Acute Low Back Pain 1999. Available from: Royal College of General Practitioners, 14 Princes Gate, Hyde Park, London, SW7 1PU. www.rcgp.org.uk

The Back Book is an evidence-based booklet for use by patients, published by The Stationery Office (ISBN 011 702 0788).


A. BACKGROUND

Principal recommendations
Make employers and workers aware that:
- LBP is common and frequently recurrent but usually brief and self-limiting.
- physical demands at work are only one factor influencing LBP.
- prevention and case management need to be directed at both physical and psychosocial factors.

Evidence
*** Physical demands at work can be associated with increased back symptoms and 'injuries', but they do not generally produce lasting physical damage. Overall, they are less important than other individual, non-occupational and unidentified factors.
*** Disability due to LBP depends more on psychosocial factors.


B. PRE-PLACEMENT ASSESSMENT

Principal recommendations
LBP is not a reason for denying employment in most circumstances. Care should be taken when placing individuals with a strong history of LBP in physically demanding jobs.

Placement should take account of the risk assessment and requirements under the Disability Discrimination Act 1995, but is ultimately a question of professional judgement.

Evidence
*** A strong history of LBP is the best predictor of future problems: frequency and duration of previous attacks, time since last attack, radiating leg pain, back surgery and sickness absence.
*** Clinical examination, x-ray, MRI, back-function testing machines and psychosocial screening are not reliable predictors.


C. PREVENTION

Principal recommendations
Advise on current good working practices such as specified in the Manual Handling Regulations and associated guidance.

Encourage employers to:
- Consider joint employer-worker initiatives to identify and control occupational risk factors.
- Monitor back problems and sickness absence due to LBP.
- Improve safety and develop a 'safety culture'.
- Recognise the importance of providing satisfying work in a climate of good industrial relations.

Evidence
*** Traditional biomedical education and lumbar supports do not reduce future LBP and work loss.
* There is conflicting evidence whether general exercise/physical fitness programmes have much preventive effect.
* Joint employer-worker initiatives to monitor and improve safety can reduce the number of reported back 'injuries' and sickness absence.


D. ASSESSMENT OF THE WORKER PRESENTING WITH BACK PAIN

Principal recommendations
Screen for serious spinal diseases and nerve root problems.
Take a detailed clinical, disability and occupational history.
Consider psychosocial risk factors for chronicity. (see 'Yellow Flags')

Evidence
** Patients aged >50 years, with more prolonged and severe symptoms or radiating leg pain are at more risk of long term disability.
** Clinical examination, x-ray and MRI do not predict clinical symptoms or work capacity.
*** Individual and work-related psychosocial factors play an important role in persisting symptoms and disability.

Psychosocial 'Yellow Flags' (beliefs and behaviours on the part of the patient which may predict poor outcomes).

The following factors are important and consistently predict poor outcomes:
· A belief that back pain is harmful or potentially severely disabling
· Fear-avoidance behaviour and reduced activity levels
· Tendency to low mood and withdrawal from social interaction
· Expectation of passive treatment(s) rather than a belief that active participation will help


E. MANAGEMENT PRINCIPLES FOR THE WORKER PRESENTING WITH BACK PAIN

Principal recommendations
Ensure that workers with LBP receive the key information in a form they understand (The Back Book) and that their clinical management follows the RCGP Guidelines (1999). Discuss expected recovery times.
Encourage the worker to continue as normally as possible and to remain at work, or to return to work at an early stage, even if they still have some LBP. Consider temporary adaptation of the job or pattern of work if necessary to achieve this.

Evidence
*** Staying active and returning to ordinary activities as early as possible leads to faster recovery and fewer recurrences.
*** Most workers with LBP are able to continue working or to return to work within a few days or weeks: they do not need to wait until they are completely pain free.
** Joint employer-worker initiatives to provide optimum management and to facilitate and support workers remaining at work or returning to work as early as possible may reduce sickness absence.


F. MANAGEMENT OF THE WORKER HAVING DIFFICULTY RETURNING TO NORMAL OCCUPATIONAL DUTIES AT APPROXIMATELY 4-12 WEEKS

Principal recommendations
Address the common misconception among workers and employers that you need to be pain-free to return to work.
Advise on ways in which the job can be adjusted to facilitate return to work.
Communicate and collaborate with primary health care professionals to shift the emphasis from dependence on symptomatic treatment to rehabilitation and self-management strategies. Where practicable refer to an active rehabilitation programme.

Evidence
*** The longer a worker is off work with LBP, the lower their chances of ever returning to work.
** Temporary provision of modified or lighter duties facilitates return to work and reduces time off work.
** Changing the focus from purely symptomatic treatment to an 'active rehabilitation programme' can produce faster return to work and less chronic disability. This is more effective in an occupational than in a health care setting.
** A combination of optimum clinical management, a rehabilitation programme, and organisational interventions designed to assist the worker with LBP return to work, is more effective.

ACTIVE REHABILITATION PROGRAMME
Education - directed at managing their pain and overcoming disability
Reassurance and advice - to stay active
Exercise - an active and progressive physical fitness programme
Pain management - using behavioural principles
Work - in an occupational setting and directed strongly towards return to work
Rehabilitation - symptomatic relief measures should support and must not interfere with rehabilitation

 

 

Evidence Review

Gordon Waddell, DSc MD FRCS
Kim Burton, PhD DO Eur Erg


 

5 EVIDENCE REVIEW METHODS

This review is about non-specific low back pain (abbreviated simply as LBP) unless otherwise stated. The main target for the literature search was evidence from occupational settings or concerning occupational outcomes. The review methodology broadly followed that used for the Royal College of General Practitioners (RCGP) clinical guidelines ((Waddell et al. 1996) (Waddell et al. 1999)) and the Swedish SBU Report on back pain (Nachemson & Jonsson 2000).

The clinical management aspects of these guidelines were based on the most recent review of the current evidence in the Swedish SBU report (1999) on back pain and the recommendations of the RCGP clinical guidelines (1999), whilst the key areas of concern to occupational health practitioners were addressed by the present literature search.

The scientific evidence on LBP is now so extensive that it is impossible to carry out a complete systematic review of every aspect of management de novo to an acceptable high standard within an acceptable time scale and using reasonable resources. The present evidence review therefore started with a search for all published, methodologically sound, systematic reviews. These were supplemented by narrative reviews in key areas of interest or where systematic reviews were unavailable. These narrative reviews were variously selected according to the following additional criteria: appropriateness to the management of occupational LBP; comprehensive and/or structured coverage of topic; basic aspects of the management of occupational LBP. Selection inevitably involved judgements of quality: the narrative reviews were selected by each of the two reviewers independently with a high level of agreement and any disagreements resolved by discussion. Further literature searches were made for original scientific studies covering key issues not covered by existing reviews, along with searches for more recent studies that might confirm, modify or expand upon the conclusions of the published systematic reviews. In addition, recent guidelines from various countries relevant to occupational health management were obtained and assessed. The resulting guidance is evidence-linked, in that sources supporting each evidence statement in this document are specifically identified.

In view of the occupational health focus of the guidelines and the present review, the following areas were excluded from the review, except where they impact directly on the guideline recommendations:

- chronic intractable pain, long-term disability and pain management programmes
- spinal surgery and post-operative states
- primary ergonomic interventions
- methods of disability evaluation
- workers compensation issues

Literature searches
The literature was searched systematically to September 1999, using a variety of standard methods.

MEDLINE was searched for articles published in English from 1966, using a number of search terms including:

- back pain or back injury
- work or occupational
- return to work
- clinical trial or intervention or prospective study
- appropriate MESH terms were also used
- (some of the systematic reviews did also include studies in other languages)

EMBASE was searched from 1980 based on a number of search terms including:

- back, low back or lumbar
- occupation, work or working
- prevention, screening, pre-employment, rehabilitation or return to work

Additional searching included:

- selected Internet searches
- personal bibliographies and personal communications
- citation tracking
- scanning of relevant journals in the field up to late 1999
- papers known to be 'in press' at the end of 1999

More than 2000 titles and abstracts were considered. Thirty-four systematic reviews were identified dealing with various aspects of management relevant to occupational health guidelines (Table 1a). The main conclusions of these systematic reviews are in Table 1b. Twenty-eight narrative reviews were selected and their main conclusions are in Table 2. Fifty two additional scientific studies (randomised controlled trials and other high quality scientific studies) are listed in Table 3. Two crucial areas in which there is limited scientific evidence are: 1) the advice that occupational health practitioners (and other health professionals responsible for clinical management) should give to patients with LBP about work and return to work; and 2) the effectiveness of return to work interventions which attempt to promote increased activities and early return to work. Twenty two additional, relevant but scientifically weaker, studies on work retention and return to work issues are in Table 4. Most of these are descriptive, retrospective or uncontrolled clinical studies and even when they are controlled they are not randomised controlled trials (RCT). Seventeen previous guidelines and one systematic review of guidelines are in Table 5. A single reference list includes all citations in the Evidence Statements and the text: although some papers in the tables are not directly cited in the Evidence Statements, all of this material is retained as a literature resource for any future work in this field. The evidence is presented under the same logical sequence of occupational health situations as in the Guidelines. The evidence statements for each situation are preceded by an introduction to the relevant issues, and some important areas are given additional discussion.

The methodology of the review may be best summarised as systematic searching plus rating of the strength of the evidence plus a narrative overview, by agreement between two experienced and independently minded reviewers. There was no attempt at blinded double review or quality scoring.

Separate tables are provided for: T1:
systematic reviews (Tables 1a & 1b)
T2: narrative reviews (Table 2)
T3: individual high quality scientific studies (Table 3)
T4: other scientifically weaker but relevant studies (Table 4)
T5: previous guidelines relevant to occupational health management (Table 5)

Evidence rating
Although the present review was based largely upon existing reviews, it was considered important in principle, and the reviews provided sufficient information to make it possible, to rate the strength of the evidence on the original scientific studies in these reviews. We used the RCGP three-star system as modified in the SBU report for scientific studies, but added a fourth category to accommodate additional clinical studies and modified the wording of the definitions slightly to allow for this.

*** Strong evidence - provided by generally consistent findings in multiple, high quality scientific studies.
** Moderate evidence - provided by generally consistent findings in fewer, smaller or lower quality scientific studies.
* Limited or contradictory evidence - provided by one scientific study or inconsistent findings in multiple scientific studies.
- No scientific evidence - based on clinical studies, theoretical considerations and/or clinical consensus.

For interventions, scientific studies were taken to be RCTs. However, RCTs are not applicable to some important areas such as the epidemiology of LBP, assessment and prognosis. In these areas, scientific studies were taken to be high quality basic science studies, major epidemiological surveys and prospective cohort studies of acute/recurrent LBP in primary care or occupational health settings. Other, scientifically weaker, clinical studies included retrospective, cross-sectional, uncontrolled cohort and descriptive studies. RCTs are in principle appropriate for workplace interventions but in that setting they are generally impractical and certainly rare, thus the evidence in this area consists mainly of weaker, clinical studies (Zwerling et al. 1997).

Evidence linking is to the most comprehensive and most recent source available. Where possible this is to systematic review(s) which should include all of the earlier, original studies in that area. Direct reference to original studies is only made where there is no adequate review, where they are not included in the review(s), or where they are necessary to support an important point. Rating the evidence on the original studies, however, may occasionally produce the paradoxical outcome that T3 evidence based on multiple RCTs can be stronger than T1 or T2 evidence based on reviews in which most of the original studies are of lower scientific quality.

Clinical judgement is necessary when using the evidence statements to guide decision making, but it is also important to consider the relative strength of the evidence. Moreover, weak evidence statements on a particular relationship or effect does not necessarily mean that it is untrue or unimportant but may simply reflect insufficient evidence or the limitations of current scientific investigations.

 

6 EVIDENCE REVIEW

A Background
Non-specific low back pain (LBP) can be occupational in the sense that it is common in adults of working age, frequently affects capacity for work, and often presents for occupational health care. It is commonly assumed this means that LBP is caused by work but the relationship between the physical demands of work and LBP is complex and inconsistent. A clear distinction should be made between the presence of symptoms, the reporting of LBP, attributing symptoms to work, reporting 'injury', seeking health care, loss of time from work and long term damage. LBP in the occupational setting must be seen against the high background prevalence and recurrence rates of low back symptoms, and to a lesser extent disability, among the adult population. Workers in heavy manual jobs do report rather more low back symptoms, but most people in lighter jobs or even those who are not working have similar symptoms. Jobs with greater physical demands commonly have a higher rate of reported low back injuries, but most of these 'injuries' are related to normal everyday activities such as bending and lifting, there is usually little if any objective evidence of tissue damage (though clinical examination and current in vivo investigations may be insensitive tools to detect this), and the relationship between job demands and symptoms or injury rates is inconsistent. Physical stressors may overload certain structures in individual cases but, in general, there is little evidence that physical loading in modern work causes permanent damage. Whether low back symptoms are attributed to work, are reported as 'injuries', lead to health care seeking and/or result in time off work depends on complex individual psychosocial and work organisational factors. The development of chronic pain and disability depends more on individual and work-related psychosocial issues than on physical or clinical features. People with physically or psychologically demanding jobs may have more difficulty working when they have LBP, and so lose more time from work, but that can be the effect rather than the cause of their LBP.

In summary, physical demands of work can precipitate individual attacks of LBP, certain individuals may be more susceptible and certain jobs may be higher risk but, viewed overall, physical demands of work only account for a modest proportion of the total impact of LBP occurring in workers.

T1:(Ferguson & Marras 1997) (Bigos et al. 1998) (Burdorf & Sorock 1997)
T2: (Garg & Moore 1992a) (Andersson 1997) (Burton 1997) (Hadler 1997) (Dionne 1999) (Waddell 1998)
T3: (Brinckmann et al. 1998)

A1 *** Most adults (60-80%) experience LBP at some time, and it is often persistent or recurrent. It is one of the most common reasons for seeking health care, and it is now one of the commonest health reasons given for work loss.

T2: (Garg & Moore 1992a) (Andersson 1997) (Waddell 1998)
(Jones et al. 1998) (Croft et al. 1998) (Department of Health 1999)

A2 *** There is strong epidemiological evidence that physical demands of work (manual materials handling, lifting, bending, twisting, and whole body vibration) can be associated with increased reports of back symptoms, aggravation of symptoms and 'injuries'.

T1: (NIOSH 1997) (Vingard & Nachemson 2000) (Ferguson & Marras 1997)
T1: (Burdorf & Sorock 1997) (Bovenzi & Hulshof 1999) T2: (Andersson 1997) (Burton 1997) (Dionne 1999) (National Research Council 1999) (Wilder & Pope 1996)
T3: (Marras et al. 1993)

A3 * There is limited and contradictory evidence that the length of exposure to physical stressors at work (cumulative risk) increases reports of back symptoms or of persistent symptoms.

T1: (NIOSH 1997) (Burdorf & Sorock 1997)
T2: (National Research Council 1999)
T3: (Marras et al. 1993) (Macfarlane et al. 1997) (Norman et al. 1998) (Burton et al. 1996)

A4 *** There is strong evidence that physical demands of work (manual materials handling, lifting, bending, twisting, and whole body vibration) are a risk factor for the incidence (onset) of LBP, but overall it appears that the size of the effect is less than that of other individual, non-occupational and unidentified factors.

T1: (Vingard & Nachemson 2000) (Ferguson & Marras 1997)
T2: (Burton 1997) (Dionne 1999)
T3: (Adams et al. 1999) (Macfarlane et al. 1997)

[Note: A2 and A4 are not incompatible. Whilst the epidemiological evidence shows that low back symptoms are commonly linked to physical demands of work, that does not necessarily mean that LBP is caused by work. Although there is strong scientific evidence that physical demands of work can cause individual attacks of LBP, overall that only accounts for a modest proportion of all LBP occurring in workers.]

A5 ** There is moderate scientific evidence that physical demands of work play only a minor role in the development of disc degeneration.

T2: (Videman & Battié 1999)
T3: (Battié et al. 1995)

A6 *** There is strong epidemiological and clinical evidence that care seeking and disability due to LBP depend more on complex individual and work-related psychosocial factors than on clinical features or physical demands of work.

T2: (Burton 1997) (Waddell 1998) (Dionne 1999)
T3: (Papageorgiou et al. 1997)

B Pre-placement assessment
Individual health, fitness and strength can affect the ability to perform tasks. Pre-placement assessment aims to identify those who may be at higher risk for LBP in a given occupational setting. The main factors that have been investigated include clinical and historical features, physical strength parameters and psychosocial factors. The recurrent nature of LBP means that previous history is the best predictor of future LBP, and all other pre-placement measures have no predictive value at all, or only a weak and unreliable predictive value.

T1: (Bigos et al. 1998) (Burdorf & Sorock 1997)
T2: (Dionne 1999) (Andersson 1997)

B1 *** There is strong evidence that the single, most consistent, predictor of future LBP and work loss is a previous history of LBP, including in particular the frequency and duration of attacks, time since last attack, radiating leg pain, previous surgery and sickness absence due to LBP.

T2: (Dionne 1999) (Andersson & Deyo 1997)

B2 ** There is moderate evidence that examination findings, including in particular height, weight, lumbar flexibility and straight leg raising (SLR), have little predictive value for future LBP or disability.

T2: (Andersson 1997) (Frank et al. 1996a)

B3 ** There is now moderate evidence that the level of general (cardio-respiratory) fitness has no predictive value for future LBP.

T2: (Andersson 1997)

B4 * There is limited and contradictory evidence that attempting to match physical capability to job demands may reduce future LBP and work loss.

T2: (Garg & Moore 1992a) (Garg & Moore 1992b) (Andersson 1997) (Andersson & Deyo 1997)

B5 *** There is strong evidence that x-ray and MRI findings have no predictive value for future LBP or disability.

T1: (van Tulder et al. 1997)
T2: (Bigos et al. 1992)
T3: (Savage et al. 1997) (Boos et al. 2000) (Borenstein et al. 1998) (Riihimaki et al. 1989)
T3: (Symmons et al. 1991a;Symmons et al. 1991b)

B6 *** There is strong evidence that back-function testing-machines (isometric, isokinetic or isoinertial measurements) have no predictive value for future LBP or disability.

T2: (Szpalski & Gunzburg 1998) (Newton & Waddell 1993)
T3: (Mostardi et al. 1992) (Masset et al. 1998)

B7 *** For symptom-free people, there is strong evidence that individual psychosocial findings are a risk factor for the incidence (onset) of LBP, but overall the size of the effect is small.

T2: (Waddell 1998)
T3: (Adams et al. 1999) (Croft et al. 1995)

High risk patients/physically demanding jobs
There is a pragmatic argument that individuals at highest risk of LBP should not be placed in jobs that impose the greatest physical demands. The basic concern is that workers with physically (or psychologically) demanding work report rather more low back symptoms, have more work-related back 'injuries' and lose more time off work with LBP. Even if physical demands of work may be a relatively modest factor in the primary causation of LBP (see Background above), people who have LBP (for whatever cause) do have more difficulty managing physically demanding work (T3: (Muller et al. 1999) T2: (Waddell 1998)). It may be argued, therefore, that avoiding putting people at highest risk of recurrent LBP and sickness absence into more physically demanding work would be in the interests of the individual worker, the employer and the total societal burden of LBP.

The problem is, a previous history of LBP simply identifies people who are more likely to have recurrent problems, but that has little to do with the job: they are probably likely to have such problems irrespective of which job they are recruited for - and even if they are not recruited (T2: (Garg & Moore 1992a) (Andersson & Deyo 1997) (Dionne 1999)). Indeed, those who remain unemployed may be at highest risk of all for chronic LBP and disability (Waddell & Waddell 2000). Because a previous history of LBP is so common, it could exclude many people who are medically fit for most work. At the same time, all pre-placement assessment methods miss many people who may later develop LBP (T1: (Andersson 1997)). There is no clear evidence for a threshold of what constitutes a strong history of LBP or excessive job demands (T4: (Garcy et al. 1996)). Most of the evidence is from a population-based perspective whilst pre-placement assessment must try to predict future risks for the individual, which is a different matter. It may be concluded that the present evidence base is insufficient for reliable selection of individuals for particular types of work (HSE 1998). Attempts to match individual susceptibility for LBP against a risk assessment of the job (and reduction of the risk of injury to the lowest level 'reasonably practicable') are therefore very much a question of judgement, and there is limited empirical evidence on their effectiveness (B4). Refusal of employment on the basis of such judgements carries substantial personal, societal, legal and political implications, and may need to take into account the requirement under the Disability Discrimination Act 1995 to provide 'suitable and reasonable' adjustments.

C Prevention
Employers have a statutory and moral responsibility to safeguard the health, safety and welfare of workers, and to take reasonably practicable steps to prevent avoidable injuries. Over the last 50 years, there have been considerable reductions in the physical demands of most work and much effort has gone into ergonomic improvements: that has reduced many serious occupational health risks, but there is inconsistent evidence on whether or to what extent it has reduced occupational LBP. Low back symptoms are common and non-specific, physical demands of work are only one causal factor, and non-occupational and psychosocial issues are important, so it may be questionable to what extent occupational interventions can realistically be expected to reduce the societal impact of LBP. It seems reasonable in principle to attempt to reduce the incidence and prevalence of LBP by interventions designed to reduce known occupational 'risk factors', but the fundamental limitation of this approach may be the lack of any clear causal link (see Background). Much depends on whether the target is reduction of symptoms, 'injuries', sickness absence or long term disability: different interventions may well have differing effects. There is a lack of convincing evidence that it is possible substantially to reduce the incidence or prevalence of the symptom of LBP. Interventions to reduce physical workload have generally had an inconsistent impact on occupational LBP - when there has been an effect it remains unclear if the interventions actually reduced 'symptoms' or 'injuries', or simply modified reporting patterns and altered what workers do about their LBP. Organisational change interventions, directed to improving job satisfaction and psychosocial aspects of work, are difficult to implement and there is conflicting evidence that they have any significant effect on health outcomes (though little of that evidence is specifically about LBP).

T1: (Ferguson & Marras 1997) (Polyani et al. 1998)
T2: (Frank et al. 1996a) (Volinn 1999)

C1 * There is contradictory evidence that various general exercise/physical fitness programmes may reduce future LBP and work loss; any effect size appears to be modest.

T1: (Lahad et al. 1994) (Gebhardt 1994)
T1: (van Poppel et al. 1997) (Dishman et al. 1998)
T2: (Kaplansky 1998) (Volinn 1999)

C2 *** There is strong evidence that traditional biomedical education based on an injury model does not reduce future LBP and work loss.

T1: (Lahad et al. 1994) (van Poppel et al. 1997) (Dishman et al. 1998)
T2: (Frank et al. 1996a) (Kaplansky 1998)
T3: (Daltroy et al. 1997)

C3 - There is preliminary evidence that educational interventions which specifically address beliefs and attitudes may reduce future work loss due to LBP.

T3: (Symonds et al. 1995)

C4 *** There is strong evidence that lumbar belts or supports do not reduce work-related LBP and work loss.

T1: (Lahad et al. 1994) (van Poppel et al. 1997)
T3: (van Poppel et al. 1998)

C5 *** There is strong evidence that low job satisfaction and unsatisfactory psychosocial aspects of work are risk factors for reported LBP, health care use and work loss, but the size of that association is modest.

T1: (Bongers et al. 1993) (NIOSH 1997) (Vingard & Nachemson 2000) (Davis & Heaney 2000)

C6 * There is limited evidence but general consensus that joint employer-worker initiatives (generally involving organisational culture and high stakeholder commitment to identify and control occupational risk factors and improve safety, surveillance measures and 'safety culture') can reduce the number of reported back 'injuries' and sickness absences, but there is no clear evidence on the optimum strategies and inconsistent evidence on the effect size.

T1: (Westgaard & Winkel 1997) (Ferguson & Marras 1997) (Dishman et al. 1998) (Polyani et al. 1998)
T3: (Hunt & Habeck 1993) (Shannon et al. 1996) (Ostry et al. 1999)
T5: (Kazimirski 1997)

D Assessment of the worker presenting with back pain
There is general consensus that a simple clinical interview and examination can distinguish between simple back pain manageable at the primary care level and those pathological conditions requiring specialist referral ('red flags' - see Figure 1). However, conventional clinical tests of spinal and neurological function are of limited value in determining appropriate clinical or occupational management of non-specific LBP. Furthermore, 'diagnostic labelling' may have detrimental effects on outcome. X-rays and MRI are primarily directed to the investigation of nerve root problems and serious spinal pathology. Much more relevant to occupational health management is the identification of individual and work-related psychosocial issues which form risk factors for chronicity ('yellow flags' - see Figure 2). General disaffection with the work situation, attribution of blame, beliefs and attitudes about the relationship between work and symptoms, job dissatisfaction and poor employer-employee relationships may also constitute 'obstacles to recovery'.

T2: (Hadler 1997)
T3: (Abenhaim et al. 1995)
T5: (Royal College of General Practitioners 1999) (Kendall et al. 1997)
T5: (Agency for Health Care Policy and Research. 1994)

D1 ** There is moderate evidence that screening for 'red flags' and diagnostic triage is important to exclude serious spinal diseases and nerve root problems.

T5: (Royal College of General Practitioners 1999)

D2 ** There is moderate evidence that patients who are older (particularly > 50 years), have more prolonged and severe symptoms, have radiating leg pain, whose symptoms impact more on activity and work, and who have responded less well to previous therapy are likely to have slower clinical progress, poorer response to treatment and rehabilitation, and more risk of long term disability.

T2: (Andersson 1997)
T3: (Cheadle et al. 1994) (Oleinick et al. 1996) (Baldwin et al. 1996)
T3: (Infante-Rivarde & Lortie 1997) (Hazard et al. 1997) (Haldorsen et al. 1998)
T4: (Lancourt & Kettelhut 1992)

D3 ** There is moderate evidence that examination findings, including in particular height, weight, lumbar flexibility and SLR are of limited value in planning occupational health management or in predicting the prognosis of non-specific LBP.

T1: (van den Hoogen et al. 1995)
T2: (Andersson 1997)

D4 *** There is strong evidence that individual and work-related psychosocial factors play an important role in persisting symptoms and disability, and influence response to treatment and rehabilitation. Screening for 'yellow flags' can help to identify those workers with LBP who are at risk of developing chronic pain and disability. Workers' own beliefs that their LBP was caused by their work and their own expectations about inability to return to work are particularly important.

T1: (Ferguson & Marras 1997)
T2: (Garg & Moore 1992a) (Waddell 1998) (Burton & Main 2000)
T4: (Sandstrom & Esbjornsson 1986) (Lancourt & Kettelhut 1992)
T4: (Carosella et al. 1994) (Fishbain et al. 1997) (Nordin et al. 1997)
T5: (Kendall et al. 1997)

D5 *** There is strong evidence that in patients with non-specific LBP, x-ray and MRI findings do not correlate with clinical symptoms or work capacity.

T1: (van Tulder et al. 1997) (Nachemson & Vingard 2000)

E Management principles for the worker presenting with back pain
Clinical aspects of management should follow the RCGP clinical guidelines (1999). Occupational health management should focus on supporting the worker with LBP and facilitating remaining at work or returning to work as rapidly as possible, and should deal with any occupational issues that may form obstacles to achieving these goals. Occupational health practitioners should liase closely with primary care. All stakeholders (i.e. the worker with LBP, supervisor(s) and management, union and health & safety representatives, the occupational health team and other health professionals undertaking clinical management) need to work closely together with a common, consistent approach to agreed goals.

T2: (Frank et al. 1996b) (Snook & Webster 1998) (Nadler et al. 1999)
T5: (Kazimirski 1997)

Clinical:
E1 *** There is strong evidence that advice to continue ordinary activities of daily living as normally as possible despite the pain can give equivalent or faster symptomatic recovery from the acute symptoms, and leads to shorter periods of work loss, fewer recurrences and less work loss over the following year than 'traditional' medical treatment (advice to rest and 'let pain be your guide' for return to normal activity).

T1: (Waddell et al. 1997) (Abenhaim et al. 2000)

E2 ** There is moderate evidence that the above advice can be usefully supplemented by simple educational interventions specifically designed to overcome fear avoidance beliefs and encourage patients to take responsibility for their own self-care.

T3: (Burton et al. 1999) (Moore et al. 2000) (Pfingsten et al. 2000)

Occupational:
E3 ** There is moderate evidence that communication, co-operation, and common agreed goals between the worker with LBP, the occupational health team, supervisors, management, and primary health care professionals is fundamental for improvement in clinical and occupational health management and outcomes.

T2: (Frank et al. 1996b) (Frank et al. 1998)
T2: (Snook & Webster 1998) (Nadler et al. 1999)
T3: (Hunt & Habeck 1993) (Shannon et al. 1996) (Ostry et al. 1999) (Loisel et al. 1997)
T4: (Wood 1987) (van Doorn 1995)
T5: (Kazimirski 1997) (van der Weide et al. 1997a)

E4 *** There is strong epidemiological evidence that most workers with LBP are able to continue working or to return to work within a few days or weeks, even if they still have some residual or recurrent symptoms, and that they do not need to wait till they are completely pain free.

T2: (Andersson 1997) (Dionne 1999) (Burton & Main 2000) (Hartigan 1996) (Hadler 1997)

E5 * Advice to continue ordinary activities as normally as possible, in principle, applies equally to work. The scientific evidence confirms that this general approach leads to shorter periods of work loss, fewer recurrences and less work loss over the following year, although most of the evidence comes from intervention packages and the clinical evidence focusing solely on advice about work is limited.

T1: (Waddell et al. 1997) (Abenhaim et al. 2000)
T2: (Hartigan 1996)
T4: (Catchlove & Cohen 1982) (Hiebert et al. 2000) (Hall et al. 1994)

E6 * There is general consensus but limited scientific evidence that workplace organisational and/or management strategies (generally involving organisational culture and high stakeholder commitment to improve safety, provide optimum case management and encourage and support early return to work) may reduce absenteeism and duration of work loss.

T1: (Westgaard & Winkel 1997) (Ferguson & Marras 1997) (Dishman et al. 1998)
T2: (Frank et al. 1996b) (Frank et al. 1998) (Snook & Webster 1998) (Nadler et al. 1999) (Hadler 1997)
T3: (Hunt & Habeck 1993) (Shannon et al. 1996)
T4: (Wiesel et al. 1994) (Nassau 1999) (van der Weide et al. 1999)

Return to work with back pain
Concern about return to work with residual symptoms is often expressed by workers themselves, their representatives, primary care health professionals, and occupational health professionals as well as supervisors and management, particularly if the LBP is attributed to work and if there is thought to be a risk of 're-injury'. This concern is natural but illogical. A recent study has highlighted the variability in physician advice on return to work and that recommendations often reflect personal attitudes of the physicians and their perception of the severity of symptoms (Rainville et al. 2000). Studies of the natural history show that LBP is commonly a persistent or recurrent problem, and most workers do continue working or return to work while symptoms are still present (Carey et al. 2000): if nobody returned to work till they were 100% symptom free only a minority would ever return to work (E4). Epidemiological and clinical follow-up studies show that early return to work (or continuing to work) with some persisting symptoms does not increase the risk of 're-injury' but actually reduces recurrences and sickness absence over the following year (E1). Conversely, the longer someone is off work the lower the chance of recovery (F1). Undue caution will form an obstacle to return to work and lead to protracted sickness absence, which then aggravates and perpetuates chronic pain and disability, and actually increases the risk of a poor long term outcome: this clearly is not in the interest of either the worker or the employer. Concerns are also sometimes expressed about legal liability for 're-injury' if the worker returns to work before they are completely 'cured' which is also illogical. Again, the natural history shows that LBP is commonly a persistent or recurrent problem, so expectations of 'cure' are unrealistic and recurrences are likely irrespective of work status. Refusing to allow a worker to return to work because they still have some LBP increases the likelihood of a break-down in worker-employer relationships and of the worker making a claim; and the longer the sickness absence the higher the cost of any claim. Helping and supporting the worker to remain at work, or in early return to work, is in principle the most promising means of reducing future symptoms, sickness absence and claims (E1, E5). Reducing any legal liability is best achieved not by forcing the worker into protracted sickness absence and possibly an adversarial situation, but by addressing the issues of job reassessment ('newly assessed duties'), the provision of modified work with adequate support, and good worker-employer relationships. All of these goals may best be achieved by the proposed active rehabilitation programme and organisational interventions (F3, Figure 3). That is also more in keeping with the spirit and the requirements of the Disability Discrimination Act.

T1: (Krause et al. 1998)
T2: (Frank et al. 1998) (Johanning 2000)
T4: (Garcy et al. 1996) (Sinclair et al. 1997) (Tate et al. 1999)
T5: (Harris 1997) (Kazimirski 1997)

F Management of the worker having difficulty returning to normal occupational duties at approximately 4-12 weeks
In general, the longer a worker is off work with LBP the more disabling the condition becomes, the less successful any form of treatment, and the greater the probability of long term sickness absence (F1). This could be explained to some extent by selection bias in that those who are off work longer are simply those with a more severe problem. However, the clinical evidence suggests that there is little if any physical difference in their backs and intervention studies show that there is usually no insurmountable physical barrier to rehabilitation (F3). There are strong logical and humanitarian arguments, and strong empirical evidence, that treatment at the sub-acute stage (approximately 4-12 weeks) is more effective at preventing chronic pain and disability than attempts to treat chronic, intractable pain and disability once it is established (F2). There is strong evidence that intervention packages at the sub-acute stage can produce desirable occupational outcomes (F3), and these efforts are likely to be more cost-effective (though there is only limited empirical evidence on costs and cost-effectiveness). There is therefore a convincing argument for intense efforts to get workers with LBP back to work before disability and sickness absence become protracted.

T1: (van Tulder & Waddell 2000) (van Tulder et al. 2000a)
T5: (Royal College of General Practitioners 1999) (INSERM 2000)
T5: (Aulman et al. 1999)

F1 *** There is strong evidence that the longer a worker is off work with LBP, the lower their chances of ever returning to work. Once a worker is off work for 4-12 weeks they have a 10-40% risk (depending on the setting) of still being off work at one year; after 1-2 years absence it is unlikely they will return to any form of work in the foreseeable future, irrespective of further treatment.

T2: (Andersson 1997) (Waddell 1998)

F2 *** Various treatments for chronic LBP may produce some clinical improvement, but there is strong evidence that most clinical interventions are quite ineffective at returning people to work once they have been off work for a protracted period with LBP.

T1: (van der Weide et al. 1997b) (van Tulder et al. 2000a) (Scheer et al. 1997)

F3 ** There is moderate evidence that for the patient who is having difficulty returning to normal activities at 4-12 weeks, changing the focus from purely symptomatic treatment to a 'back school' type of rehabilitation programme can produce faster return to work, less chronic disability and less sickness absence. There is no clear evidence on the optimum content or intensity of such packages, but there is generally consistent evidence on certain basic elements (Figure 3). There is moderate evidence that such interventions are more effective in an occupational setting than in a health care setting.

T1: (van Tulder et al. 1999) (Di Fabio 1995) (Karjalainen et al. 1999)

F4 ** From an organisational perspective, there is moderate evidence that the temporary provision of lighter or modified duties facilitates return to work and reduces time off work.

T1: (Krause et al. 1998)
T2: (Frank et al. 1998)

F5 - Conversely, there is some suggestion that clinical advice to return only to restricted duties may act as a barrier to return to normal work, particularly if no lighter or modified duties are available.

T4: (Hiebert et al. 2000) (Hall et al. 1994)

[Note: These two evidence statements are not incompatible. The agreed goal should be to return to as near normal duties as possible as rapidly as possible, and clinical advice and management must not undermine that, but the best means of achieving this goal may be by the provision of modified or lighter duties for a limited period.]

F6 ** There is moderate evidence that a combination of optimum clinical management, a rehabilitation programme, and organisational interventions designed to assist the worker with LBP return to work, is more effective than single elements alone.

T1: (van Tulder et al. 1999) (Di Fabio 1995)
T2: (Frank et al. 1996b) (Frank et al. 1998) (Snook & Webster 1998) (Nadler et al. 1999)
T3: (Loisel et al. 1997)
T4: (Haig et al. 1990) (Ryan et al. 1995) (van Doorn 1995) (Yassi et al. 1995) (Tate et al. 1999)
T5: (Kazimirski 1997) (van der Weide et al. 1997a)

Rehabilitation Programmes
Most of the above principles could be combined in an active rehabilitation programme (see Figure 3), although there is wide variation, lack of clear definition and considerable confusion about exactly what constitutes an effective programme. Some forms of 'back school' or 'multidisciplinary rehabilitation' at the sub-acute stage have produced faster recovery of pain and disability, faster return to work and fewer recurrences over the following year than other treatments to which they have been compared (E1, F3). However, the results are inconsistent, probably because most studies are of packages of interventions of widely varying content and intensity. There is no clear evidence on the optimum content or intensity of such packages, although there is generally consistent evidence on certain basic elements.

Education alone is a relatively weak intervention. Traditional biomedical information and advice based on spinal anatomy, biomechanics and an injury model is largely ineffective (T3: (Roland & Dixon 1989) (Cherkin et al. 1996)) but completely different information and advice, designed to overcome fear avoidance beliefs and promote self-responsibility and self-care, can produce positive shifts in beliefs and reduce disability (T3: (Burton et al. 1999) (Moore et al. 2000)) (Snook et al. 1998).

All of the effective rehabilitation programmes have included a progressive active exercise and physical fitness element (T1: (Di Fabio 1995) (van Tulder et al. 1999)). Such exercise programmes can produce short-term improvement in pain and disability for sub-acute and chronic LBP, although there is no clear evidence that any specific type of exercise has any specific physical effect (T1: (van Tulder et al. 2000b)).

There are theoretical considerations and empirical evidence that most of the effective programmes are based on behavioural principles of pain management (T1: (van Tulder et al. 1999) T2: (Waddell 1998)), but there are few studies which look at this approach in isolation ((Fordyce et al. 1986) (Turner 1996)). There is moderate evidence that these programmes are more effective in an occupational setting (T1: (van Tulder et al. 1999)).

The interventions, resources and costs should be strictly controlled. There is insufficient evidence to justify intensive and expensive programmes and they are likely to be less cost effective. The rehabilitation programme should be closely audited and evaluated to check that it is effective and not having any unplanned adverse effects.

Previous guidelines
A number of guidelines (Table 5) were identified that are relevant to the occupational health management of LBP; though some focus mainly on clinical management. They adopted differing methods for locating and assessing the evidence base, which vary from highly systematic, through consensus appraisal to personal interpretation, and they have been published in varying forms through various media.

Despite the differing methodologies and target audiences, the guidance on LBP has come to broadly similar conclusions in a number of important respects (Burton & Waddell 1998). The clinical guidelines consistently advocate some sort of diagnostic triage to distinguish between non-specific LBP and back pain due to an identifiable pathology (see Figure 1). For non-specific LBP, the guidance stresses the fundamental importance of prevention of chronicity, and advocates an early, active management approach involving consideration of psychosocial factors. In general terms, for primary care management at the acute stage, patients are advised to remain active and then at the sub-acute stage progressive exercise is encouraged, but there is some inconsistency as to where the dividing line should be drawn. The most recent of these guidelines is the 1999 revision of the 1996 RCGP guidelines in UK (Royal College of General Practitioners 1999). The earlier CSAG report (Clinical Standards Advisory Group. 1994) also addressed the provision of NHS and rehabilitation services in UK.

Most primary care guidelines mention occupational issues, in particular the question of early return to work, as part of general advice on activity but they do not fully address the issues facing the worker with LBP or the occupational health practitioner. A few do address occupational issues slightly more fully, but they come from development groups with differing perspectives and none of them are evidence-linked. In general, the guidelines simply follow the primary care approach of early active management as a strategy to prevent undue disability, whilst the work-related guidance follows a broadly consistent pattern, focusing particularly on workplace factors. There is a general tendency to address obstacles to recovery rather than primary prevention, and job modification is seen as an appropriate aid to remaining at work or early resumption of work. A major feature of the occupational (as opposed to clinical) guidance is the concept that work organisation and communication between workers and supervisors/management are important elements of occupational health management; education both of workers and employers is seen as important.

There is now extensive scientific evidence and general agreement in the guidelines about how the clinical and occupational management of non-specific LBP can and should be improved. There is at present very little empirical evidence on whether such guidelines are implemented or change practice, or if the recommended practice does actually deliver improved clinical and occupational outcomes.

T2: (Volinn 1999)
T5: (Westgaard & Winkel 1996) (van der Weide et al. 1997a)

Evidence gaps in occupational health management of LBP
This review has found considerably more scientific evidence on the occupational health management of LBP than originally anticipated, despite the methodological problems in a workplace setting (Zwerling et al. 1997). There is sufficient evidence to permit a number of strong and moderate evidence statements and recommendations for occupational health management, but this review, however, has also identified inadequacies in the evidence in some important areas.

There is a need for further rigorously designed and carefully controlled studies (where appropriate by RCTs and with sub-categorisation of patients) on:
· Pre-placement assessment, particularly matching (strong) previous history of LBP, physical capabilities and job demands.
· 'Innovative' education approaches to prevention and management specifically designed to overcome psychosocial issues (eg fear avoidance beliefs) and encourage patients to take responsibility for their own self-care.
· Company policies on accident prevention, 'safety culture', surveillance and monitoring to reduce reported back 'injuries' and claims.
· The relative benefits and costs of prescribing sick certification for LBP.
· Early interventions to overcome obstacles to recovery (e.g. focused clinical interventions targeting individual 'yellow flags' for chronicity).
· The optimum combination and relative importance of individual components in an active rehabilitation programme.
· The optimum organisation, content and combination of case management, active rehabilitation and return to work programmes.
When possible, cost-effectiveness analysis should be included in future studies.

Acknowledgements
The reviewers would like to express their appreciation and thanks to Serena Bartys, BSc for her assistance with the literature searches and for securing copies of the selected papers. Thanks are also expressed to Debbie Brown for her administrative and secretarial contribution.

 

7 EVIDENCE TABLES

Table 1a - Systematic reviews

Authors
Date
Subject

Occup.
setting


Occup. outcomes
Number of studies Additional Comments
Background
(Bongers et al. 1993)
1993
Psychosocial risk factors at work
+/-
-
30 30
(NIOSH 1997)
1997
Risk factors
+
+
49 physical
13 psychosocial
(Burdorf & Sorock 1997)
1997
Occupational and individual risk factors
+
-
35 Estimates strength of association
(Bigos et al. 1998)
1998
Risk factors & primary prevention
+
+
17 prospective cohort & case control studies risk factors + 3 RCTs prevention
(Vingard & Nachemson 2000)
1999
Occupational risk factors
+
-
41 Physical 27 psychosocial Largely symptoms
(Hoogendoorn et al. 1999)
1999
Physical load during work and leisure time as risk factors for LBP
+
-
28 cohort 3 case-referent Largely symptoms
(Bovenzi & Hulshof 1999)
1999
Whole body vibration
+
-
17 cross-sectional, longitudinal and case control Meta-analysis
(Davis & Heaney 2000)
2000
Psychosocial work characteristics
+
-
66 psychosocial Symptoms only. Methodological critique
Prevention
(Lahad et al. 1994)
1994
Primary prevention
+
-
62 studies with original data Back exercises Educational strategies Lumbar supports
(Gebhardt 1994)
1994
Training
+
+
6 Meta-analysis
(Westgaard & Winkel 1997)
1997
Ergonomic and workplace interventions
+
+
20 ergonomic modification 32 production system 39 secondary prevention 'Musculoskeletal health'
(van Poppel et al. 1997)
1997
Primary prevention in industry
+
+
11 controlled trials Back exercises Educational strategies Lumbar supports
(Ferguson & Marras 1997)
1997
Surveillance measures and risk factors
+
+
57
(Dishman et al. 1998)
1998
Worksite physical activity interventions
+
-
26 Outcome: activity level or physical fitness. Not specifically LBP
(Polyani et al. 1998)
1998
Workplace organisational changes
+
+
21 case studies Health outcomes. Not specifically LBP
Assessment of the worker presenting with back pain
(van den Hoogen et al. 1995)
1995
Accuracy of history & physical examination
-
-
36 (cohort studies) Meta-analysis of sensitivity and specificity
(van Tulder et al. 1997)
1997
X-rays
-
-
35 Meta-analysis
(Nachemson & Vingard 2000)
1999
MRI
-
-
14 studies
Management principles for the worker presenting with back pain
(van Tulder & Waddell 2000) 1999 Clinical treatment Acute & subacute LBP - +/- 98 RCTs SBU In press
(Waddell et al. 1997) 1997 Bed rest Advice to stay active -
+/-

+/-
+/-
10 RCTs
8 RCTs
(Abenhaim et al. 2000) 1999 Activity +/- +/- Systematic review and guideline. Paris Task Force In press
(van Tulder et al. 1999) 1999 Back schools +/- +/- 15 RCTs Cochrane review
(Faas 1996) 1996 Specific back exercises - - 11 RCTs 4 acute
1 sub-acute
6 chronic
(van Tulder et al. 2000b) 1999b Exercise therapy - - 39 RCTs No conclusions about occupational outcomes
(Scheer et al. 1995) 1995 Occupational outcomes acute LBP + + 10 RCTs <4 weeks duration conservative interventions
(van der Weide et al. 1997b) 1997 Occupational outcomes + + 40 RCTs
Management of the worker having difficulty returning to normal occupational duties at approximately 4-12 weeks
(van Tulder et al. 2000a)
1999c
Clinical treatment chronic LBP
-
-
96 RCTs SBU In press
(Scheer et al. 1997)
1997
Occupational outcomes sub-acute & chronic LBP
+
+
12 RCTs Non-surgical interventions
(Cutler et al. 1994)
1994
Pain centre treatment
+/-
+
37 cohort studies Employment outcomes + meta-analysis
(Di Fabio 1995)
1995
Comprehensive rehabilitation programmes
+/-
+
19 RCTs Meta-analysis
(Faucett 1999)
1999
Early interventions Acute and sub-chronic LBP
+/-
+
16 quantitative 6 qualitative 10 RCTs
(Feuerstein & Zastowny 1999)
1999
Multidisciplinary occupational rehabilitation
+
+
7 controlled studies(1 RCT) Chronic LBP
(Karjalainen et al. 1999)
1999
Multidisciplinary rehabilitation
+
+
12 Musculoskeletal disorders
(Krause et al. 1998)
1998
Modified work & return to work
+
+
29 empirical studies Few RCTs

Table 1b - Main conclusions of systematic reviews
* Original authors' main conclusions from Abstract, Results and Discussion. (Present reviewers' comments in brackets and italics)

Systematic review Subject Original authors' main conclusions *
Background
(Bongers et al. 1993)

Psychosocial risk factors at work

The high correlation between psychosocial factors and mechanical loading makes it difficult to draw firm conclusions. Nevertheless, there is evidence that monotonous work, high perceived workload and time pressure, and suggestive evidence that low control on the job and lack of social support are associated with musculoskeletal symptoms. Stress may be an intermediary.
(NIOSH 1997)

Risk factors

A large, systematic review considering the epidemiological evidence on risk factors for a wide variety of work-related musculoskeletal disorders, including LBP. It concluded that there is strong evidence for a causal relationship between lifting/forceful movements and whole body vibration and LBP; there is evidence for a causal relationship between awkward postures and heavy physical work and LBP; there is insufficient evidence to assume a causal relationship between static work posture and LBP. It is noted that the association applies when exposures are intense, prolonged and multiple, but it is accepted that the multifactorial origins of LBP may be associated with both work and non-work-related factors. There is increasing evidence that psychosocial aspects of work play a role in the development of LBP, and seem to be independent of physical factors. (This review does not clearly distinguish between incidence, prevalence, injury, chronicity, and work loss, and simply assumes that statistical associations represent a causal relationship. Because of the focus on risk factors as opposed to outcomes, it provides little information on work retention or return-to-work issues where some of these factors may actually be more important.) See also Table 2: National Research Council 1999
(Burdorf & Sorock 1997)

 






 

 

Occupational and individual risk factors





 

 

 

This review aimed to identify important risk factors for work-related back disorders, to present information on the strength of association and estimate their relative contribution to the occurrence of back disorders in occupational populations. Considers physical and psychological factors + certain individual factors. Lifting or carrying loads, whole-body vibration and frequent bending and twisting were found to be consistently associated with back disorders. There were contradictory and generally negative findings on static work postures and repetitive movements. Job dissatisfaction and low decision latitude found to be important, but somewhat inconsistent (though this review only included a small number of studies on psychosocial aspects of work). Age, smoking and education are confounding factors in epidemiological studies. Gender, height, weight, exercise and marital status were found not to be associated with back disorders in occupational populations.
(Bigos et al. 1998) Risk factors & primary prevention This (methodologically very rigorous) review only accepted a limited number of high quality studies: 3 on prevention, 12 retrospective cohort studies and 5 case control studies. The authors concluded that there is insufficient evidence to assess the outcome of specific interventions to prevent back injury or back complaints at work.
(Vingard & Nachemson 2000)




Occupational risk factors

 

Most studies are cross-sectional and concern reports of pain. Nevertheless, the authors concluded that there is a constant but weak relationship between physical work load factors and reports of LBP. The impact of occupation on LBP is modest except for extreme working conditions for prolonged periods without the possibility of changing work tasks. Whole body vibration is a particular risk. Certain psychosocial factors at work also appear to be related to reporting LBP, but most of the studies are cross-sectional, there is confounding with physical work load, and the effect is probably weak. There are theoretical arguments that improving psychosocial aspects of work has the potential for reducing back complaints at work, but at present there is little or no empirical evidence.
(Hoogendoorn et al. 1999)

Physical load during work and leisure time as risk factors for LBP

(This is the most up-to-date and comprehensive review of the effect of physical demands of work.) There is strong evidence for manual materials handling (lifting, moving, carrying and holding loads), bending and twisting, and whole-body vibration as risk factors for reporting LBP; moderate evidence for patient handling and heavy physical work; contradictory evidence for standing or walking, sitting, sports, and total leisure-time physical activity.
(Bovenzi & Hulshof 1999)

Whole body vibration

Occupational exposure to whole body vibration is associated with an increased risk for LBP, sciatic pain and degenerative changes, but the cross-sectional nature of most of the evidence is insufficient to establish a clear exposure-response relationship.
(Davis & Heaney 2000)

Psychosocial work characteristics

 

(This is the most comprehensive and methodologically critical review of psychosocial aspects of work.) There are considerable methodological weaknesses to most studies. Controlling for physical work load significantly weakens the association between psychosocial aspects of work and LBP. In view of the methodological weaknesses it is difficult to draw firm conclusions. Nevertheless, there is strong evidence for a weak relationship between certain psychosocial aspects of work and reported LBP. Workers' reactions to psychosocial aspects of work (e.g. job dissatisfaction and job stress) are more consistently related to reported LBP than psychosocial aspects of work themselves (e.g. work overload, lack of control over work, quality of relationship with co-workers).
Prevention
(Lahad et al. 1994)

Primary prevention

Review of four specific interventions. The authors concluded that there is limited evidence that exercises to strengthen back and abdominal muscles and improve physical fitness can reduce the incidence and duration of LBP episodes. They found minimal evidence for educational strategies and insufficient evidence about lumbar supports. There is no evidence for any specific effects from stopping smoking and reducing weight.

(Gebhardt 1994)

Training

Meta-analysis of six experimental studies showed that training programmes including education and physical fitness had a statistically significant but modest effect on the incidence and duration of work loss due to LBP.
(Westgaard & Winkel 1997)

Ergonomic and workplace interventions

Although this review included 92 studies, they were not strictly ergonomic and very few were RCTs. The most effective interventions were 1) 'organisational culture' using multiple interventions with high stakeholder commitment to reduce identified risk factors, and 2) modifier interventions focussing on workers at risk and using measures which actively involve the individual. However, serious methodological weaknesses mean that there is insufficient scientific evidence to draw any firm conclusions about the impact or effect sizes of these interventions.
(van Poppel et al. 1997)

Primary prevention in industry

This review included 11 controlled studies of which 7 were RCTs. 4 out of 5 studies of lumbar supports showed that they were ineffective. 5 out of 6 studies of very varied types of 'education' showed no effect. All three studies of various exercise programmes showed a medium effect.
(Ferguson & Marras 1997)

Surveillance measures and risk factors Surveillance measures fall into four main types (adapted slightly by the present reviewers): survey of symptoms; reported injury; incidence surveillance from medical or occupational health records, lost time from work. These different surveillance measures may be viewed as a temporal or severity progression. The authors analysed a wide range of physical and psychosocial risk factors at work against these different surveillance measures, and showed that the findings depended on which surveillance measure was used. As LBP progresses from symptoms to disability, psychosocial (as opposed to physical exposure) factors play a more prominent role.
(Dishman et al. 1998) Worksite physical activity interventions These interventions are classified as health risk appraisal, health education, behavioural modification or cognitive behavioural programmes, exercise prescription, or combinations of these. Meta-analysis showed that the studies were heterogeneous and the effect size small (r = 0.11) and non-significant.
(Polyani et al. 1998) Workplace organisational changes Interventions directed to improving job satisfaction and psychosocial aspects of work are difficult and only 4 out of 11 case studies demonstrated any significant effect on worker stress, mental health or absenteeism. (However, none of that evidence is specifically about LBP.)
(van den Hoogen et al. 1995) Accuracy of history & physical examination This is a systematic review of individual items of clinical history and examination, focused mainly on the diagnosis of specific spinal pathologies. It points out the limited reliability and validity of most clinical data.
Assessment of the worker presenting with back pain
(van Tulder et al. 1997) X-rays There is no firm evidence for a causal relationship between radiographic findings and LBP. There is an association between diagnostic disc degeneration, age and history of LBP, but the relationship is relatively weak and insufficient to make any assessment of the individual patient, and the nature of the evidence does not permit any causal interpretation. There is no relationship between LBP and spondylosis, spondylolysis/spondylolisthesis, spina bifida or transitional vertebrae. Any relationship to Scheuermann changes is inconclusive. This very extensive review only found two prospective studies of the predictive value of plain x-rays (Riihimaki et al 1989, Symmons et al 1991, Table 4).
(Vingard & Nachemson 2000) MRI High prevalence of abnormal findings in normal asymptomatic subjects. The authors questioned the reliability of routine reporting. MRI findings bear little relationship to past or present clinical symptoms.
Management principles for the worker presenting with back pain
(van Tulder & Waddell 2000) Clinical treatment Acute & subacute LBP Evidence base for current clinical management as in RCGP (1999) clinical guidelines. Strong evidence for NSAIDs, muscle relaxants, avoiding bed rest and advice to stay active. Conflicting interpretation of evidence on manipulation, (although most other reviews consider there is strong evidence for manipulation in acute LBP.)
(Waddell et al. 1997) Bed rest

Advice to stay active

Bed rest is not an effective treatment for acute LBP but may delay recovery. Advice to stay active and continue normal activities results in faster return to work, less chronic disability and less time off work in the following year.
(Abenhaim et al. 2000) Activity More extensive discussion of the practical implications of the evidence against bed rest and for advice to maintain or resume normal activities, as far as pain allows. Patients with subacute, intermittent or recurrent LBP should be encouraged to follow an active exercise programme. In principle, recommendations about activities of daily living are equally applicable to return to work, but there is a lack of scientific evidence.
(van Tulder et al. 1999) Back schools Although this review included 15 RCTs, they were a very heterogeneous group of interventions and the methodological quality was low. The authors concluded that there is moderate evidence that 'back schools' have better short term effects than other treatments for chronic LBP and that there is moderate evidence that 'back schools' in an occupational setting are more effective than placebo or waiting list controls. (The major problem to this review is the difficulty of defining what constitutes a 'back school' and the authors do not attempt to distinguish which elements are associated with successful outcomes.)
(Faas 1996) Back exercises Only 11 RCTs were included published up to early 1995. In acute LBP specific exercises are ineffective. In sub-acute LBP, there was limited evidence at that time for a graded activity programme. In chronic LBP (>12 weeks), there was some evidence for the short-term efficacy of an intensive exercise programme.
(van Tulder et al. 2000b) Exercise therapy There is strong evidence that exercise therapy is not effective for acute LBP. There is strong evidence that exercise therapy is more effective than 'usual care' and that exercise therapy and conventional physiotherapy are equally effective for chronic LBP. The authors conclude that exercises may be useful within an active rehabilitation programme if they aim at improving return to normal daily activities and work, but specific back exercises have no clinical effect.
(Scheer et al. 1995) Occupational outcomes acute LBP Lack of evidence at that time that any treatment was effective in terms of return to work outcomes.
(van der Weide et al. 1997b) Occupational outcomes 40 RCTs of clinical interventions for all durations of LBP reported vocational outcomes. For acute patients there was limited or moderate evidence that avoiding or restricting the duration of bed rest, and spinal manipulation produced better vocational outcomes.
Management of the worker having difficulty returning to normal occupational duties at approximately 4-12 weeks
(van Tulder et al. 2000a) Clinical treatment chronic LBP (>12 weeks) Evidence base for clinical management. There is strong evidence for the effectiveness of manipulation, exercise therapy and multidisciplinary pain treatment programmes, especially with regard to short term effects. There is moderate evidence for behavioural therapy. However, there is a lack of evidence that any treatment has much effect on long-term outcomes or for any effect on the long-term natural history of LBP.
(Scheer et al. 1997) Occupational outcomes sub-acute & chronic LBP This review included 12 RCTs published by 1993 of non-surgical clinical interventions for sub-acute (4-12 weeks) and chronic (> 12 weeks) LBP which gave vocational outcomes. The authors considered most of the trials had serious methodological weaknesses. 4 trials of various types of exercise therapy and 5 trials of various types of cognitive and behavioural therapy did not provide any clear evidence of any significant effect on vocational outcomes.
(Cutler et al. 1994) Pain centre treatment This review included 37 studies but very few were RCTs and many were uncontrolled. Meta-analysis showed that a multidisciplinary, functional restoration approach for chronic LBP doubled the number of patients who returned to work. (However, Teasell & Harth 1996 (T2) pointed out that these authors completely failed to consider the lack of proper controls for these results.)
(Di Fabio 1995) Comprehensive rehabilitation programmes This review contrasted 'back schools' as a primary intervention with 'back schools' as part of comprehensive rehabilitation programmes. Meta-analysis showed that back schools coupled with a comprehensive programme were more effective for clinical outcomes of pain, physical impairment and knowledge/compliance. However, disability and vocational outcomes were not significantly better than control groups for either approach.
(Faucett 1999) Early interventions for LBP (Comprehensive review of prospective studies of natural history and outcome and of the perspectives of patients with chronic LBP.) The review included 10 RCTs of a wide range of educational and counselling interventions and considered they 'fall within the scope of nursing practice' (but did not provide clear conclusions about the evidence.)
(Feuerstein & Zastowny 1999) Multidisciplinary occupational rehabilitation for chronic LBP and disability This is a review of multidisciplinary occupational rehabilitation programmes for chronic LBP published 1984-1994. It includes 7 controlled studies but only one of these was an RCT. The mean return to work rate for these interventions was 71% (range 59-85%) compared with 44% for the controls, but the authors point out the lack of proper randomised controls.
(Karjalainen et al. 1999) Multidisciplinary rehabilitation This is the most recent Cochrane review of multidisciplinary rehabilitation for subacute LBP and various other musculoskeletal disorders. It includes 12 relevant studies but none were high quality RCTs. Two studies were of LBP alone, though most of the others included patients with LBP. The authors concluded that there is moderate evidence for the effectiveness of multidisciplinary rehabilitation for sub-acute LBP for functional outcomes and return to work. (However, only Lindstrom et al 1992 and Loisel et al 1997 are included in this review.)
(Krause et al. 1998) Modified work & return to work This review of 29 empirical studies showed that modified work programmes doubled the number of injured workers who return to work and halved the number of lost work days. 11 studies dealt with LBP alone and another 11 were of all injuries including LBP: the results for LBP appear to be comparable. Most modified work consisted of light duties, although there were also some trials of graded work exposure and work trial periods, and in most studies modified work formed part of a much broader programme. (There was only one RCT - Loisel et al 1996).

Table 2 - Narrative reviews
* Original authors' main conclusions from Abstract, Results and Discussion. (Present reviewers' comments in brackets and italics)

Authors Original authors' main conclusions *
Background
(Garg & Moore 1992a) LBP is an extremely significant cause of disability with major socio-economic impact, but many different personal and job factors are associated with incidence and prevalence of complaints. It is difficult to relate LBP to the workplace because it is common in sedentary as well as heavy physical work, but increased physical demands and heavy lifting, particularly lifting combined with bending and twisting, are associated with more reported LBP and sickness absence. The inherent variability between and within workers precludes assigning risk to any particular individual.
(Krause & Ragland 1994) Proposal of an eight-phase classification of disabling LBP, based on duration of work disability and taking account of other biomedical and social characteristics of work disability resulting from LBP. Prevention of disability requires interdisciplinary approach.
(IASP 1995) Focus on disentangling pain and disability aspects of LBP. Promotes biopsychosocial perspective and time-contingent as opposed to pain-contingent management.
(Wilder & Pope 1996) Review of epidemiological evidence linking whole body vibration exposure and LBP, with discussion of potential aetiological factors. Concludes that there is a clear relationship between whole body vibration environments and LBP. However, the relationship between intrinsically and extrinsically applied mechanical stresses and the accompanying hard and soft tissue deformations (both acute and chronic) requires further definition.
(Andersson 1997) A (comprehensive and authoritative) review of the epidemiology of spinal disorders.
(Burton 1997) Biomechanics/psychosocial aspects: Biomechanics/ergonomics related to LBP symptom reports but not to disability and work loss - here psychosocial and work organisational factors dominate; this distinction impacts on strategies for management.
(Waddell 1998) Comprehensive review of the evidence base for the biopsychosocial model and current clinical guidelines. Reproduces the 1996 RCGP and New Zealand guidelines, and 'yellow flags' document. (Chap 5: epidemiology. Chap 6: risk factors. pp 96-7: psychological predictors of LBP. pp 107-112: rate of return to work. pp 113-116: predicting chronicity).
(Videman & Battié 1999) Occupational loading only has a small influence on disc degeneration, and there is no clear dose-response relationship. Twin studies indicate that the combined effect of genes and early childhood environment are more important than occupational exposure.
(Dionne 1999) IASP Epidemiology of pain. Up-to-date, critical review of the epidemiology of adult mechanical LBP. Also concludes that pre-employment selection methods (medical evaluation, strength testing and x-rays) are ineffective and raise ethical and legal questions.
(National Research Council 1999) Work-related musculoskeletal disorders: report of a workshop. There is a strong association between biomechanical stressors at work and reported musculoskeletal pain, injury, loss of work and disability. There is a strong biological plausibility to the relationship between the incidence of musculoskeletal disorders and high-exposure occupations, but methodological weaknesses make it difficult to draw strong causal inferences or to establish the relative importance of task and other factors. Evidence that lower levels of biomechanical stress are associated with musculoskeletal disorders remains less definite. Research clearly demonstrates that reducing the amount of biomechanical stress and interventions which tailor corrective action to individual, organisational and job characteristics can reduce the reported rate of musculoskeletal disorders for workers who perform high-risk tasks. (This review covered all musculoskeletal disorders and there is very little information specifically on LBP.)
Pre-placement assessment
(Bigos et al. 1992) Pre-employment screening 13 x-ray studies. X-rays do not predict future back injury claims or chronic disability. (Most of the studies are actually cross-sectional and not predictive.)
(Newton & Waddell 1993) Testing with back-function testing machines does not predict future LBP.
(Andersson 1997) P 114-125 (Comprehensive and authoritative) review of individual risk factors. Anthropometric or postural measurements, including in particular height, weight or body build, do not correlate strongly with LBP or predict future LBP (although there is conflicting evidence on whether tall subjects are more likely to develop disc prolapse). Four prospective studies considered isometric strength. Two studies (by the same author) found that workers whose job demands approached or exceeded their measured strength were 3x more likely to develop LBP during the following year. One study found that workers whose strength was matched to job demands tended to have fewer complaints during 1 year follow up. One study found that isometric strength did not predict future claims for back injury at work. Three out of four prospective studies showed that cardiovascular fitness did not predict future LBP (though that is a separate question from whether it influences recovery).
(Andersson & Deyo 1997) Theoretical analysis of the effect of pre-employment screening. History of LBP alone has low sensitivity and specificity. Because history of LBP is highly correlated with age, 20% of age 30 and 75% of age >50 would be judged 'at risk' of future low back disability, but 75% of future disability would be missed. Positive x-rays calculated to have only 40% predictive value for future work loss. No evidence available on predictive value of static strength tests.
(Szpalski & Gunzburg 1998) Whilst LBP patients have weaker trunk muscles than controls, the results from back-function testing machines have not been shown to have predictive value for future episodes of LBP.
Prevention
(Garg & Moore 1992b) Ergonomic job design and job-specific strength testing (related to manual load handling) have potential to identify high-risk workers, but require further validation.
(Frank et al. 1996a) Primary prevention of disability from occupational LBP. A review of the risk factors for the onset of LBP and associated disability. Studies of pre-employment screening, including medical examination, x-rays and strength tests are ineffective in predicting who will develop disabling LBP and 'need to be considered carefully in the context of human rights and employment legislation'. Most forms of workplace interventions attempting to change workers are ineffective, though exercise programmes show some promise. Ergonomic interventions have 'had a difficult time under controlled conditions trying to translate (their) theoretical potential into an observable and reliable reduction in LBP disability'.
(Hadler 1997) Compensable back injuries: distinguish between injury and pain; physical stress only partly explanatory; task context is as important as task content; workplace should be 'comfortable when we are well and accommodating when we are ill'.
(Kaplansky 1998) Job design/redesign and exercise programmes may have a protective effect, but trials are lacking. Evidence does not support use of structured workplace education, back belts or worker selection.
(Volinn 1999) Methodological critique. Whilst some workplace interventions have been reported to be effective in reducing back injuries, methodological problems inherent in pragmatic studies render their results inconclusive. There is suggestive evidence that workplace interventions (of various types) may have an effect but explanatory studies are required.
Assessment of the worker presenting with back pain
(Burton & Main 2000) This review suggests a paradigm shift from medical concepts of prevention and cure to concentration on removal of obstacles to recovery. In addition to individual psychosocial 'yellow flags', it is becoming apparent that work-related factors ('blue flags' such as attribution, beliefs about work/injury, disaffection, perceived work demands, work organisation, managerial attitudes, return-to-work policies) are especially important occupational obstacles to recovery.
Management
(Teasell & Harth 1996) Functional restoration. This is a highly critical review which points out the serious methodological short-comings of most published trials, including selection bias, lack of proper controls, limitations of outcome measures and inappropriate analysis. The only RCT at that time failed to show any efficacy of such a functional restoration programme.
(Hartigan 1996) This review suggests that patients with acute LBP should be educated that pain is a normal part of recovery, and that activity maintenance improves outcome; some may wish to develop a health-club or home maintenance regimen. Incorporation of direct return to work advice is important, along with direct communication with employer. Successfully managed patients will feel confident about abilities for work and general activities.
(Frank et al. 1996b) Secondary prevention of disability from occupational LBP. A review of the natural history of LBP and the risk factors for chronic disability, as the basis for secondary interventions to reduce the duration of occupational disability. Current clinical guidelines are based on extensive scientific evidence but there is little evidence that the guidelines are implemented or effective. Despite the lack of high quality RCTs, the authors conclude that there is strongly suggestive evidence for several workplace-based interventions. 1) Management retraining to more acceptance and accommodation of LBP, facilitating prompt reporting and treatment, including active rehab services at work, and the provision of modified duties. 2) Pro-active and employee-supported communication between the workplace, injured worker, health care and other involved parties. 3) 'Managed care' to ensure optimum medical treatment and rehabilitation, according to the best scientific evidence and current guidelines. 4) Integration of all these elements in a comprehensive intervention programme in the workplace.
(Frank et al. 1998) Secondary prevention of LBP disability, concentrating on the stage of intervention. Management in the first 3-4 weeks should be conservative according to current clinical guidelines. Interventions at the sub-acute stage (between 3-4 and 12 weeks) should focus on return to work and can reduce time lost from work by 30-50%. There is substantial evidence that appropriately modified work can reduce the duration of work loss by at least 30%. A combination of these approaches in a co-ordinated, guidelines-based and work place-linked care system can reduce sickness absence due to LBP by 50% at no extra cost.
(Snook & Webster 1998) Evidence-based approach to reduction of industrial LBP disability. Focus on co-operation between management and clinicians; training/educating supervisors and workers; concern by supervisors; early treatment access; adaptation of workplace; reduce attribution; pro-active, company-based, early return to work programme.
(Nadler et al. 1999) Sports medicine approach: Prompt evaluation and initiation of treatment, active as opposed to passive rehabilitation and early return to work. Communication with all parties (including case managers under managed care arrangements).
(Johanning 2000) A clinical practice review of occupational low back disorders, with the goal of optimising the quality of care by developing a model of care that integrates medical care with preventive efforts. Concludes that many injuries and pain syndromes are of multifactorial aetiology. Recommends 'standard ambulatory care' (and recognition of 'red flags'). Return to work should be based on thorough understanding of the workplace with control of identifiable risk factors to prevent further injury. Psychosocial factors, work organisational structures, and compensation benefits play an important part in rehabilitation. Occupational health physicians are well placed to be directly involved.

Table 3 - Individual scientific studies
* Original authors' main conclusions from Abstract, Results and Discussion. (Present reviewers' comments in brackets and italics)

Authors Type of study Subject Original authors' main conclusions *
Background
(Marras et al. 1993) Cross-sectional Biomechanics and epidemiology of LBP 400+ repetitive industrial lifting jobs categorised as high or low risk from medical/injury records and monitored biomechanically. Combination of 5 trunk motion and workplace factors (lifting frequency, load moment, trunk lateral velocity, trunk twisting velocity, trunk sagittal angle) distinguished between high and low risk. Though not proving causality, an association between biomechanical factors and low back disorder risk was indicated.
(Battié et al. 1995) Retrospective cohort Spinal degeneration MRI findings in identical twins showed that the extent of lumbar disc degeneration was explained primarily by genetic and familial influences and age; the influence of physical work load had very modest effects (0-7% of the variance).
(Norman et al. 1998) Case control study Biomechanical factors Analysis of exposure to peak and cumulative lumbar loading parameters in LBP cases and controls. Cumulative biomechanical variables stated to be important risk factors in the reporting of LBP. Workers in the top 25% of loading exposure about 6 times more likely to report LBP. This study concerns reported LBP as opposed to confirmed 'injury' or work loss.
(Brinckmann et al. 1998) Retrospective cohort Overload injuries and exposure to physical stressors Radiological findings show that spinal loading (from heavy physical work and vibration) can result in irreparable overload damage to lumbar discs. However the level of loading required to cause this damage is not likely to be met in modern workplaces. Relationship between damage and symptoms is unclear.
Pre-placement assessment
(Croft et al. 1995) Prospective population study Psychological distress Symptoms of psychological distress in individuals free of LBP predict onset of new episodes during following 12-months. Proportion of new episodes potentially attributable to psychological factors is 16%.
(Papageorgiou et al. 1997) Prospective cohort Work-related psychosocial factors People dissatisfied with work are more likely to report LBP for which they do not consult a physician, whilst lower social status and perceived inadequacy of income are independent risk factors for seeking consultation because of LBP during the follow-up year.
(Macfarlane et al. 1997) Prospective cohort Physical factors related to employment Occupational activities such as work with heavy objects or long periods of standing or walking were associated with occurrence of LBP in women but not in men. Short-term influences may be more important than cumulative exposure for new episodes.
(Adams et al. 1999) Prospective cohort Personal risk factors Previous history of any LBP, personal physical and psychological risk factors were highly significant predictors of 'any' and 'serious' LBP, but only accounted for 12% of the variance in total. Overall, these risk factors were relatively unimportant in the population studied, though they could still be decisive in the individual case. Anthropometric factors, body weight and back strength did not predict. Occupation had little predictive value, though the study was limited by most people being in similar work.
(Muller et al. 1999) 15 year prospective cohort Influence of previous LBP, previous sick listing and working conditions on future sick listing for LBP The strongest predictors were previous history of LBP, especially if sciatic pain, analgesics and previous sick listing, and sick listing behaviour in general. Blue collar work was a significant but weaker predictor, and there was an interaction between history of LBP and occupation.
(Riihimaki et al. 1989) 5 year prospective cohort. Clinical findings

X-rays

Previous history of LBP was the best predictor of sciatica. Degenerative changes on initial x-ray did not predict sciatica after adjustment for age.
(Symmons et al. 1991a)

(Symmons et al. 1991b)

9 year prospective population study of 1009 middle age women Clinical findings

X-rays

Degenerative changes on initial x-ray did not predict onset of new LBP in those with no previous history of LBP or recurrent LBP in those with a previous history of LBP. Continuing LBP was not related to deterioration of disc degeneration during follow up. The strongest predictor of progressive degenerative changes was the presence of degeneration at onset, but that was quite separate from symptoms.
(Savage et al. 1997) Prospective cohort MRI in asymptomatic subjects. No clear relationship between MRI findings and LBP. MRI findings not related to type of occupation. No change in MRI appearance in those subjects who developed new onset LBP during one year follow up. MRI findings did not predict new LBP on one year follow-up. Authors concluded that MRI is not suitable for pre-employment screening.
(Boos et al. 2000) Prospective cohort MRI in selected asymptomatic subjects with MRI abnormalities. MRI findings did not predict significant new LBP or sciatica or work absence or medical consultation with 5 year follow-up.
(Borenstein et al. 1998) Prospective cohort MRI in asymptomatic subjects. MRI did not predict significant new LBP or sciatica on 7 year follow-up.
(Mostardi et al. 1992) Prospective cohort Isokinetic lifting strength of high-risk nurses. Did not predict LBP or back injury on 2 year follow-up.
(Newton et al. 1993) Prospective cohort Cybex isokinetic assessment of normal subjects. Did not predict new LBP on 2.5 year follow-up.
(Dueker et al. 1994) Prospective cohort LIDO isokinetic trunk testing of job applicants No significant difference in initial isokinetic scores of workers who had occupational low back injury over 6 year follow-up.
(Masset et al. 1998) Prospective cohort Isostation B200 isoinertial trunk testing of workers with no previous history of LBP. Workers with history of LBP performed tests at lower velocity, but probability for development of LBP in following year greater for those performing tests at greater velocities. (Contrary to the author's own conclusions, the results showed no consistent relationship between isoinertial performance and new LBP on 2 year follow-up.)
Prevention
(Hunt & Habeck 1993) Cross-sectional Study of employer policies and practices. (The Michigan Disability Prevention Study) Safety diligence, Pro-active return to work programmes, and Safety training and Active safety leadership are associated with significantly fewer days off work. Ergonomic interventions and Wellness orientation did not have significant effects, while Disability case monitoring could be counter-productive.
(Shannon et al. 1996) Cross-sectional survey of 718 workplaces Study of employer policies and practices. Fewer lost-time WCB claims (all injuries) were associated with: concrete demonstration by management of its concern for the workforce; greater involvement of workers in company decision making; greater willingness of the Health & Safety Committee to solve problems internally; and an older, more stable, more experienced workforce.
(Symonds et al. 1995) Controlled trial Trial of educational pamphlet in industry An educational pamphlet produced a positive shift in beliefs about LBP that was accompanied by a concomitant reduction in 'extended' absence related to LBP. The pamphlet intended to reduce fears about LBP and advised on longer-term advantages from work retention and early return to work.
(Daltroy et al. 1997) RCT Primary prevention - back school This RCT in 4000 postal workers showed that a back school had no effect on low back injuries during 5.5 years follow-up.
(van Poppel et al. 1998) RCT Lumbar supports for primary prevention. Lumbar supports and/or instruction on lifting techniques did not reduce incidence of LBP or absence.
(Ostry et al. 1999) Cross-sectional Study of workplace organisation. Manager's assessment of high staff job satisfaction and senior management's review of health and safety performance; and labour's assessment of the involvement of senior management, supervisors and line employees in safety inspections and the availability of job retraining for injured workers; were associated with lower company claim rates.
Assessment of the worker presenting with back pain
(Cheadle et al. 1994) Cohort study Predictors of duration of work loss in 28,473 US WCB injuries Even after adjusting for severity of injury, older age, female gender and back strains were associated with longer time off. Heavier work and smaller firms also had a significant but weaker effect. The authors recommend that disability prevention efforts should be directed to those at higher risk.
(Abenhaim et al. 1995) Prospective cohort study Diagnostic labelling Physicians' making of 'specific' initial diagnoses such as sciatica, disc lesions, facet joint syndrome or osteoarthritis (without any independent verification of pathology) was highly associated with the risk of chronic disability at 6 months compared with 'non-specific' diagnoses of pain, sprains or strains . This was partly a question of case mix, but also reflected the effect of 'labelling'.
(Oleinick et al. 1996) Cohort study Predictors of acute (<8 weeks) and chronic (> 8 weeks) work loss in 8628 US WCB claimants with back injuries followed for 6 years. Different predictors at acute and chronic stages. For both acute and chronic disability the most important predictor was increasing age, particularly over age 55 years. Smaller companies also had higher risk of chronic disability. The authors conclude that management strategies may need to vary at different ages and that new strategies are required to encourage small and medium size companies to help injured workers return to work and earlier.
(Baldwin et al. 1996) Cohort study Ontario WCB survey of workers with permanent impairment followed for 17 years. Initial return to work was less likely with back strains, increasing age, unmarried men and married women, lower education, and various socio-economic factors. However, although 85% did initially return to work, more than half then had further absences. In a second analysis of long-term work patterns, 21% had further absences before successfully continued working, and 11% had further absences before giving up work. Further absences and eventually giving up work were most likely in those with back injuries, increasing age, less education and various socio-economic factors. The authors conclude that personal and socio-demographic factors are more important than biomedical factors in determining occupational outcome. Employers' accommodations of reduced hours and light work were associated with fewer further absences and more successful work retention.
(Infante-Rivarde & Lortie 1997) Cohort study Relapse and absence in first episode of compensated LBP Incidence of relapse or short sickness absence in first six months after return to work was predicted only by overall pain and pain associated with carrying out simple daily movements assessed at discharge (socio-demographic, clinical features and workers' views were not predictive).
(Ingermarsson et al. 1997) Clinical cohort study Predictors of duration of work loss. In workers with sub-acute LBP (4-8 weeks off work), the best predictor of sickness absence over the next year was total sickness absence in the previous year.
(Lehmann et al. 1993) Clinical cohort study Predictors of duration of work loss. In workers with sub-acute LBP (2-6 weeks off work), the best predictors of chronic incapacity at 6 months were perception that LBP was work-related and absence duration
(Hazard et al. 1997) RCT Early physician notification and guidelines A predictive questionnaire successfully identified patients at high risk of developing work absence at 3 months, but early physician referral and clinical guidance did not produce any significant improvement in pain, return to work or satisfaction with care.
(Nordin et al. 1997) Cohort study Prospective - workers with lost-work episode of LBP Model Clinic approach. Comprehensive clinical examination and assessment of psychosocial factors within 1-week of lost-work time. Multivariate model for prediction of delayed return to work (> 1 month) included physical, behavioural and job factors, and supported the biopsychosocial model of LBP. Biopsychosocial factors (yellow flags) should be considered at onset of injury.
(Haldorsen et al. 1998) Cohort study Predictors of failure to return to work within 12 months Patients sick listed for 8-12 weeks entered a light mobilisation programme that encouraged them to be active participants in management. Low benefit from the programme was predicted by low internal health locus of control, restricted lateral mobility and reduced work ability.
Management principles for the worker presenting with back pain
(Vroomen et al. 1999) RCT Bed rest for disc prolapse and sciatica Bed rest is no more effective than watchful waiting.
(Roland & Dixon 1989) RCT Trial of a traditional educational booklet in primary care. The booklet produced significant improvement in knowledge and significantly fewer repeat consultations with LBP, but made no difference to days off work over the next year.
(Cherkin et al. 1996) RCT Trial of a traditional educational booklet A traditional educational booklet had no significant effect compared with 'usual care'. An individual educational session with a practice nurse produced greater knowledge and patient satisfaction but did not influence clinical outcomes.
(Burton et al. 1999) RCT Trial of a novel educational booklet in primary care Primary care delivery of an educational booklet that specifically addresses fear avoidance beliefs by giving positive messages about prognosis, activity and work retention produced a positive shift in beliefs and short-tem reduction in disability.
(Moore et al. 2000) RCT Educational programme in primary care. A brief cognitive-behavioural intervention designed to provide accurate information, reduce fears and worries, encourage self care and improve functional outcomes produced significant improvement in worries, fear-avoidance, pain intensity and function, and more favourable attitudes about self care.
(Pfingsten et al. 2000) RCT Experimental study in patients with chronic LBP Inducing pain anticipation produced increased pain intensity, anxiety and fear-avoidance beliefs, and poorer performance during a non-provocative physical performance test. Reassurance produced the opposite effects.
Management of the worker having difficulty returning to normal occupational duties at approximately 4-12 weeks
(Greenwood et al. 1990) RCT Coal miners within 2 weeks of back injury. Early intervention, case management approach. Patients with psychosocial risk factors seen by nurse and counsellor who offered guidance, co-ordinated their primary and specialist care and physiotherapy, and if necessary arranged psychological services. No difference in time off work but increased medical costs in the early intervention group.
(Mitchell & Carmen 1990) RCT Trial of functional restoration for LBP 3-6 months off work. 79% of functional restoration patients working at 1 year compared with 78% of controls.
(Jarvikoski et al. 1993) Prospective trial: Quasi-experimental comparison of multi-modal treatment programmes Intensive training with 'no pain, no gain' rationale produced greater improvement in pain and functional capacity, but did not decrease absence compared with the less intensive programme. Suggests more active interventions addressing work and work-life are needed.
(Alaranta et al. 1994) RCT Trial of functional restoration Functional restoration improved range of movement, muscle strength and endurance but these effects fell off by 12 months. Functional restoration improved self-reported performance and disability. However. there was no difference in sick leave over the next year between the functional restoration group and controls.
(Loisel et al. 1997) RCT Trial of a model of management for sub-acute LBP (>4-6 weeks off work) This was a population-based trial of a highly organised system involving close co-operation between the injured worker, supervisor, and labour and management representatives. The occupational intervention started with assessments by an occupational health physician and an ergonomist. All of the parties then visited the work site to observe the worker's tasks, reach an 'ergonomic diagnosis' and prescribe specific improvements in work tasks, all directed to stable return to work. The clinical intervention consisted of a visit to a back specialist and a back school, followed by a multidisciplinary functional restoration rehabilitation programme if still off work at 12 weeks. The combination of the clinical and occupational interventions produced 2.4x faster return to regular work than usual care. The occupational part of the intervention had the larger impact.
(Ljunggren et al. 1997) RCT Physiotherapy patients Supervised motivated exercise programme -v- exercise on their own. Absenteeism reduced similarly in both groups in the second year; no effect from supervised programme.
(Bendix et al. 1998a) (Bendix et al. 1998b) Two separate RCTs Two trials of functional restoration for chronic LBP with > 6 months disability The first RCT showed that an intensive functional restoration programme produced significantly fewer sick days and contacts with the health care system than untreated controls. The second RCT showed that the intensive functional restoration programme produced a significantly higher proportion returning to work and significantly fewer sick leave days than a less intensive control programme. These effects were maintained at 2 and 5 years.
(Frost et al. 1998) RCT Trial of a fitness programme for chronic LBP An 8 session physical fitness programme over 4 weeks was based on a sports medicine approach and cognitive behavioural principles. This fitness programme combined with an educational back school produced significantly lower self-reported disability at 2 years compared with the back school alone.
(Friedrich et al. 1998) RCT Trial of a combined exercise and motivation programme with a standard physiotherapy exercise programme The motivation group had higher short term compliance and significantly less pain and self-reported disability at one year, but long-term exercise compliance was no different. 20% more of the compliance group returned to their previous level of work by 4 months, which was of borderline significance.
(Lonn et al. 1999) RCT Trial of an active back school Intensive, active back school of 20 sessions over 3 months significantly reduced the frequency and severity of recurrences over 1 year follow-up.
(Klaber-Moffett et al. 1999) RCT Trial of exercise programme with cognitive behavioural component in primary care Exercise programme produced significantly greater improvement in Roland disability scale at 6 and 12 months. Days off work during 12 month follow up was reduced by 30% but this did not reach statistical significance.
(Kankaanpaa et al. 1999) RCT Trial of active rehabilitation for chronic LBP Exercise programme produced significantly greater improvement in Roland disability scale at 6 and 12 months. Days off work during 12 month follow up was reduced by 30% but this did not reach statistical significance.

Table 4 - Additional studies on work retention and return to work.
* Original authors' main conclusions from Abstract, Results and Discussion. (Present reviewers' comments in brackets and italics)

Authors Subject Original authors' main conclusions *
Assessment of the worker presenting with back pain
(Sandstrom & Esbjornsson 1986) Prospective - rehabilitation programme Patients' own estimate of their ability to return to work before they undertook a rehabilitation programme was the best predictor of actual return to work after rehabilitation. The rehabilitation process seemed to have marginal influence on outcome in patients with clearly expressed negative attitudes.
(Lancourt & Kettelhut 1992) Prospective - workers with LBP Nonorganic factors are better predictors of return to work than organic findings. X-ray, myelogram and CT findings did not predict time off work. Length of time off work was highly predictive. Different factors important at different stages. For <6 months the important predictors were high disability score, leg pain, short tenure on job and examination findings of illness behaviour. For> 6 months off these were not predictive but previous injuries and stability of family living arrangements were.
(Carosella et al. 1994) Prospective - intensive rehab programme Patients' own beliefs about return to work were best predictor of dropping out of rehab programme, better than severity of pain, duration of time off work or perception of work.
(Fishbain et al. 1997) Prospective - chronic pain patients Multidisciplinary pain centre patients questioned on job perceptions and 'intent' to return to work. There was an association between pre-injury job perceptions and actual return to work. The patient's own assessment before treatment of inability to return to work was highly predictive of not returning to work after the treatment.
(Devereux et al. 1999) Cross-sectional study Looked at physical and psychosocial risk factors in a high-high, high-low, low-high, low-low exposure groups and compared with self-reports of LBP. Suggests an interaction between physical and psychosocial risk factors at work may exist to increase the risk of self-reported back disorders. Suggests ergonomic interventions should not only focus on physical but also on psychosocial factors at work.
Management of the worker presenting with back pain
(Catchlove & Cohen 1982) Retrospective - compensation patients Comparison of two groups attending a pain Management Unit. Patients in one group were positively instructed to return to work as an integral part of the treatment programme (rather than being the goal of treatment). Significantly more of this group (60% v 25%) returned to work, and at 10-month follow-up 90% were still at work and received less treatment.
(Hiebert et al. 2000) Historical cohort Prescription of work restrictions by the occupational health physician made no difference to duration of work loss. Work restrictions remained in place for longer than physiological healing time. Prescription of work restrictions was associated with reduced chance of return to original work in next 12-months. (There was no significant difference in the risk of recurrence: i.e. prescription of work restrictions did not reduce the risk of 're-injury').
(Hall et al. 1994) Prospective - comparing two recommendations about return to unrestricted work Therapists' advice on return to restricted or unrestricted duties is usually based on patients' reports of pain or therapists' unfounded fears that return to work would result in harm. During the first phase of this study (control) the therapist accepted pain as a reason for advising half the patients to return to restricted work only. In the second, study phase most patients were advised to return to normal work, irrespective of pain. Advice to return to normal work doubled the number who returned to normal duty, while patients advised about restricted duties were less likely ever to return to normal duties.
(Wiesel et al. 1994) Prospective 10-year study of management protocol for LBP. Evidence based, standardised diagnostic and treatment protocols and independent specialist monitoring produced 50% fall in new injuries, 40% fall in average days off, and total 55% fall in days lost from work.
(Nassau 1999) 10.5 year retrospective study - hospital employees. Integrated programme of pre-employment screening for at-risk jobs, close case management, early return to work policy and availability of modified work. In general, the injury rate did not change but the average duration of work loss fell slightly from 4.5 to 3.8 days. However, there was a dramatic and highly significant reduction in the injury rate and average number of lost work days among those workers screened.
(van der Weide et al. 1999) Cohort study Assessed implementation of OH guidelines (see van der Weide et al 1997 - Table 5) using criteria for physician compliance. If guidelines are met, then outcome is better (working status at 3 months and time lost). If patients attributed their LBP to work they were less satisfied with the intervention by the physician, but overall satisfaction with health care was not related to work outcomes.
Management of the worker having difficulty returning to normal occupational duties at approximately 4-12 weeks
(Wood 1987) Prospective - nursing workforce A Personnel Programme (hospital-wide effort to increase communication between claimants, doctors, compensation board and the employer, including in particular the worker's supervisor phoning to say: 'How are you? We are thinking about you. You are a vital part of the team. Your work is important and your job is waiting for you.') cut the number who stayed off long-term with back injuries from 7.1% to 1.7% A Back Programme (intensive feedback training on patient handling) did not significantly reduce back injuries.
(Haig et al. 1990) Prospective hospital workers

Historical controls

Aggressive early management by a specialist in physical medicine who evaluated employees at 2 days off work and delivered standard treatment more efficiently. Overall, this significantly reduced the duration of work loss, but for LBP only from an average of 8.8 to 7.5 days.
(Ryan et al. 1995) Prospective - miners A back pain programme was instituted comprising workforce education, early injury reporting, first aid at workplace, changing workplace psychosocial perceptions and involvement of management and employees. Compared with another mine, the programme significantly reduced the number of claims and costs per claim.
(van Doorn 1995) Prospective - self-employed health professionals claiming insurance. An early intervention programme delivered by an insurance physician reduced mean and cumulative LBP disability, and recurrence. A time-dependant approach involved mutual trust between physician and claimant, and focused on advice on active rehabilitation and early gradual return to work. Part-time or limited duties were always possible, but pain was not a reason for recommending this.
(Yassi et al. 1995) Prospective - nurses Compared with pre-programme data and control wards, an early intervention programme in 10 high risk wards (comprising prompt assessment, treatment and rehabilitation through modified work) reduced the number of reported back injuries by 23% and lost-time back injuries by 43%; intervention was cost-beneficial.
(Garcy et al. 1996) Prospective - chronic LBP Assessed incidence of claimed recurrence after functional restoration. Even for this sample of severe chronic disabling LBP patients, who completed a tertiary prevention programme, a relatively low risk for either recurrence was found. Neither physical nor psychological risk factors for recurrence could be found. Findings argue against employer bias in not rehiring employees with previous chronic LBP, or discrimination in pre- or re-employment on the basis of putative risk of re-injury after appropriate rehabilitation programme.
(Ehrmann-Feldman et al. 1996) Prospective - compensation cases Data collected from workers' compensation records of 2,147 LBP claimants. Of patients referred for physical therapy, those referred earlier tended to return to work sooner than those referred later.
(But no allowance for case mix or selection bias.)
(Burton et al. 1996) Retrospective - police officers Following first reported episode of LBP 8% of police officers changed duties (5% moved to heavier work; 3% to lighter work). Most returned to their previous tasks, many of which entailed hazards identified for first time LBP. Persistence at the same work was not related to persistence of symptoms over 6 years following onset. Attribution of LBP to police work and psychological distress were associated with work loss.
(Sinclair et al. 1997) Prospective - workers absent with LBP Large scale follow-up of Mitchell & Carmen 1990 (see Table 3). 1 year follow up of 2000 injured workers on an early, intensive rehab programme. Programme made no difference to pain, disability or quality of life but increased average duration of work loss by 7 days, attributed to too early intervention when many patients would have recovered anyway, keeping workers off work to attend the programme, and administrative stopping of communication between rehab physicians and the workplace.
(Tate et al. 1999) Prospective - cohort of nurses Back injured nurses targeted for workplace early intervention. Time loss due to LBP during 6 months after back injury analysed. Perceived disability was related to whether time loss would ensue. Self-reported pain strongly associated with duration of time loss once injury had become a time loss injury. Injury while lifting patients resulted in greater time loss. Participation in the return-to-work programme (including modified duties) reduced the duration of work loss. Focusing on reducing perception of disability at time of injury was considered critical to preventing time loss, but once time loss occurred, offer of modified work and attention to pain reduction were said to be warranted.
(Wigley et al. 1990) Early v late functional restoration programme Two cohorts entered the programme <6 months or> 6 months from injury. Those treated earlier achieved greater gains in functional performance (VO2 max, spinal flexion, lifting capacity).

Table 5 - Previous guidelines


Title/Source
Country
Main focus and recommendations
(Summarised by present reviewers)


Clinical
Clinical Practice Guideline: Acute low back problems in adults.

(Agency for Health Care Policy and Research. 1994)

USA
The first modern, evidence-based and -linked, clinical guideline for the management of LBP. Diagnostic triage and 'red flags'. Limited evidence for most therapies. Bed rest >4 days is not helpful and may be debilitating. Activity modification during acute LBP and then as recovering encourage to return to work and to normal activities as soon as possible. Psychological and socio-economic factors may be addressed.
Report on back pain.

(Clinical Standards Advisory Group. 1994)

UK
Report on present and future NHS services for LBP. First UK clinical guidelines with algorithms on diagnostic triage and primary care management of non-specific LBP. Advice on staying active and return to work. Need for biopsychosocial assessment at 6 weeks and the development of dedicated services and multidisciplinary rehab services for patients with non-specific LBP.
Counselling to prevent low back pain.

National Guideline Clearing House

(US Preventive Services Task Force 1996)

USA
Evidence linked recommendations on advice that may be given to prevent LBP. Insufficient evidence to recommend for or against counselling on exercise, educational intervention, back belts, risk factor modification, obesity, smoking.
Guidelines for the management of employees with compensable low back pain.

(Victorian Workcover Authority. 1996)

Australia
Assessment and clinical management of workers with compensable LBP to prevent disability. Advocates active management, advice and early return to work
New Zealand Acute Low Back Pain Guide

ACC/National Advisory Committee on Health and Disability

(ACC and the National Health Committee 1997)

New Zealand
Evidence based approach to assessment and treatment of acute LBP with a view to preventing chronicity and disability. Active management approach against suggested time frames with declared intention to change attitudes of clinicians and patients.
Guide to Assessing Psychosocial Yellow Flags in Acute Low Back Pain: Risk Factors for Long-Term Disability and Work Loss

ACC / National Advisory Committee on Health and Disability

(Kendall et al. 1997)

New Zealand
Assessment of psychosocial factors that are likely to increase the risk of chronicity in acute LBP. Screening for psychosocial factors and strategies for better management of those at risk. Active management and advice to reduce distress.
Health Care Guideline: adult low back pain.

Institute for Clinical Systems Integration

(ICSI 1998)

USA
Update of AHCPR (1994). Evidence based assessment protocols and treatment plans. Time contingent management. Continuance of activity (rather than rest); reassurance; educational leaflet; medication; self-care; physical therapy. Comprehensive re-evaluation at 6-weeks; then rehabilitation/exercise therapy.
Clinical guidelines for the management of acute low back pain.

Royal College of General Practitioners

(Royal College of General Practitioners 1999)

UK
Evidence-linked guidance on assessment and treatment of acute LBP in primary care. Diagnostic triage; medication to control pain; avoid bed rest; promote activity; maintain/resume work; consider manipulation; rehabilitation if not active at 6-weeks.
Paris Task Force.

The role of activity in the therapeutic management of back pain.

((Abenhaim et al. 2000)

(also listed in systemic reviews; Table 1)

France
Extensive discussion of the practical implications of the evidence against bed rest and for advice to maintain or resume normal activities, as far as pain allows. Patients with sub-acute intermittent or recurrent LBP should be encouraged to follow an active exercise programme. Theoretically, recommendations about activities of daily living appear applicable to return to work, but in view of the lack of scientific evidence the Task Force authorised rather than recommended return to work.
Occupational
Supervisor's Handbook: Supervising to prevent and manage back injuries.

The Saunders Group Inc

(Pollock et al. 1991)

(still being distributed in UK by BackCare)

USA
Didactic and not evidence based. Emphasises the importance of communication with and involvement of workers in back injury prevention. Management must be actively involved in claims control and management, with the aim of returning the injured worker to work as soon as possible. Detailed sequence of claims management programme. Supervisors should:
Educate workers about back care and set standards.
Supervise use of proper body mechanics.
Be involved in work site evaluation, modification and redesign.
Encourage team work and use of lifting devices.
Require use of proper safety clothing and equipment.
Design jobs to minimise size and bulk of loads, minimise reach and distance to be moved, and allow sufficient time.
Return injured worker to work as soon as possible.

(Westgaard & Winkel 1996)

(systematic review)

-
A systematic review of guidelines for occupational musculoskeletal load. Present guidelines are only based on laboratory studies aiming to reduce short-term physiological or psychological effects. Most guidelines are directed to the level of work load rather than the repetitions or duration of work load. There is little or no empirical evidence on the effectiveness of any of these guidelines. The authors conclude that current guidelines are inadequate and may be misleading.
Occupational Medicine Practice Guidelines.

(Harris 1997)

USA
Assessment and treatment of potentially work-related acute and sub-acute LBP. Largely a reproduction of AHCPR (1994) with a few supplementary comments on occupational health issues which are not evidence based or linked. Generally avoid bed rest; promote activity and/or job modification; promote exercise; early return to work; investigate and address psychosocial, workplace or socio-economic factors.
Guidelines on work site prevention of low back pain.

Labour Standards Bureau

(Yamamoto 1997)

Japan
Un-referenced guidance on work site prevention through ergonomic factors; work organisation; pre-placement examinations; education; manual handling. Advice on handling, accommodation, sitting, pre-work and at-work exercises.
The physician's role in helping patients return to work after an illness or injury.

Canadian Medical Association

(Kazimirski 1997)

Canada
Policy statement addressing the clinician's role. Highlights communication between patient and employer for early treatment and return to work; importance of addressing obstacles to recovery; developing modified work plan; recognition of employees' family and workplace roles; importance of employer-employee relationship in return to work.
(van der Weide et al. 1997a)

(guidelines audit)

Netherlands
Guidelines for occupational LBP rehabilitation developed. Intervention between 2 and 4 weeks. Diagnostic triage, match abilities/demands, co-operation from 'relevant others' - treatment/management with focus on barriers to early return to work. Authors recommend use of guidelines with recording of physician 'performance' of guideline principles.
Practice guidelines for occupational physicians: workers with low-back pain.

(Aulman et al. 1999)

Netherlands
Adaptation of Dutch clinical guideline for occupational physicians, evidence based but not evidence linked. Target - workers off sick with LBP. Aim - to prevent unnecessarily long sickness absence and chronic disability. Assessment includes psychosocial problems, illness behaviour, experience of disabilities, adequacy of treatment, work environment & psychosocial factors, fitness for work. For non-specific LBP, advice includes reassurance about the good prognosis and the importance of maintaining usual activities. If no further problems, return to work within two weeks, if necessary conferring with the treating physician, and providing temporary adaptations in working hours or tasks and psychological support. If problems: re-evaluate within two weeks. If no progress within two weeks: refer to a graded activity programme. If no progress within 12 weeks: refer to a rehabilitation or back care centre.
Low back pain at the workplace: risk factors and prevention.

(INSERM 2000)

France
Expert literature synthesis (rather than a systematic review). Risk factors generally consistent with other reviews. Recommendations include disseminating information ('The Back Book' (Anon 1996)), better surveillance, better follow-up and advice to those at risk of chronicity. Early prevention: awareness campaigns, joint worker-management campaigns to reduce occupational risks and improve organisational aspects of work, and general safety training rather than specifically on LBP. Prevention of chronicity: evaluate workers off sick for 4 weeks with LBP and develop combined health care and occupational interventions. Proposed pilot project and evaluation of a rehab programme for chronic LBP.
(Poole 1999)
UK
Describes a pre-placement health assessment to classify high, medium and low risk for future sickness absence. Includes LBP and aspects of its previous history. (This is a personal, untested view and is not based on a systematic review.)
 

8 REFERENCES

Abenhaim L, Rossignol M, Gobeille D, Bonvalot Y, Fines P, Scott S 1995. The prognostic consequences in the making of the initial medical diagnosis of work-related back injuries. Spine; 20: 791-795.

Abenhaim L, Rossignol M, Valat J-P, Nordin M 2000. The role of activity in the therapeutic management of back pain. Spine; (in press)

ACC and the National Health Committee 1997. New Zealand acute low back pain guide. Wellington, NZ, Ministry of Health (www.nhc.govt.nz).

Adams MA, Mannion AF, Dolan P 1999. Personal risk factors for first-time low back pain. Spine; 24: 2497-2505.

Agency for Health Care Policy and Research. 1994. Acute Lower Back Problems in Adults. Clinical Practice Guideline No. 14. Washington DC, US Government Printing Office.

Alaranta H, Rytokoski U, Rissanen A, Talo S, Ronnemaa T, Puukka P, Karppi S-L, Videman T, Kallio V, Slatis P 1994. Intensive physical and psychosocial training program for patients with chronic low back pain: A controlled clinical trial. Spine; 19: 1339-1349.

Andersson GBJ 1997. The epidemiology of spinal disorders. in Frymoyer JW (ed). The adult spine: principles and practice. 93-141. Philadelphia, Lippincott-Raven.

Andersson GBJ, Deyo R 1997. Sensitivity, specificity and predictive value. in Frymoyer JW (ed). The adult spine: principles and practice. 2nd: 308-310. Philadelphia, Lippincott-Raven.

Anon 1996. The Back Book. Norwich, The Stationery Office (www.tsonline.co.uk).

Aulman P, Bakker-Rens RM, Dielemans SF, Mulder A, Verbeek JHAM 1999. Hendelen van de bedrijfsarts bij werkemers met Lage-Rugklachten (Practice guidelines for occupational physicians: workers with low-back pain). Eindoven, Nederlanse Vereniging voor Arbeids-en Bedrijfsgeneekunds (NVAB) (in Dutch).

Baldwin ML, Johnson WG, Butler RJ 1996. The error of using returns-to-work to measure the outcomes of health care. Amer J Industr Med; 29: 632-641.

Battié MC, Videman T, Gibbons L, Fisher L, Manninen H, Gill K 1995. Determinants of lumbar disc degeneration: a study relating lifetime exposures and MRI findings in identical twins. Spine; 20: 2601-2612.

Bendix AF, Bendix T, Haestrup C, Busch E 1998. A prospective, randomized 5-year follow-up study of functional restoration in chronic low back pain patients. European Spine Journal; 7: 111-119.

Bendix AF, Bendix T, Labriola M, Boekgaard P 1998. Functional restoration for chronic low back pain: two-year follow-up of two randomized clinical trials. Spine; 23: 717-724.

Bigos SJ, Battié MC, Fisher LD, Hansson TH, Spengler DM, Nachemson AL 1992. A prospective evaluation of preemployment screening methods for acute industrial back pain. Spine; 17: 922-926.

Bigos SJ, Wilson MR, Davis GE 1998. Reliable science about avoiding low back problems at work. in Wolter D, Seide K (ed). Berufsbedingte Erkrankungen der Lendenwirbelsaule. 415-425. Hamburg, Springer-Verlag.

Bongers PM, de Winter CR, Kompier MAJ, Hildebrandt VH 1993. Psychosocial factors at work and musculoskeletal disease. Scandinavian Journal of Work and Environmental Health ; 19: 297-312.

Boos N, Semmer N, Elfering A, Schade V, Gal I, Hodler J, Zanetti M, Main CJ 2000. Psychosocial factors and not MRI-based disc abnormalities predict future low-back pain-related medical consultation and work absence. Spine; (in press)

Borenstein G et al 1998. A 7-year follow-up study of the value of lumbar spine MR to predict the development of low back pain in asymptomatic individuals. Presented to International Society for the Study of the Lumbar Spine, Brussels, June 9-13.

Bovenzi M, Hulshof CT 1999. An updated review of epidemiologic studies on the relationship between exposure to whole-body vibration and low back pain (1986-1997). International Archives of Occupational and Environmental Health; 72: 351-365.

Brinckmann P, Frobin W, Biggemann M, Tillotson M, Burton K 1998. Quantification of overload injuries to thoracolumbar vertebrae and discs in persons exposed to heavy physical exertions or vibration at the work-place. Part II. Occurrence and magnitude of overload injury in exposed cohorts. Clinical Biomechanics; 13 (Suppl. 2): S(2)1-S(2)36.

Burdorf A, Sorock G 1997. Positive and negative evidence of risk factors for back disorders. Scandinavian Journal of Work and Environmental Health; 23: 243-256.

Burton AK 1997. Back injury and work loss: Biomechanical and psychosocial influences. Spine; 22: 2575-2580.

Burton AK, Main CJ 2000. Relevances of biomechanics in occupational musculoskeletal disorders. in Mayer TG, Gatchel RJ, Polatin PB (ed). Occupational musculoskeletal disorders: function, outcomes and evidence. 157-166. Philadelphia, Lipincott-Raven.

Burton AK, Tillotson KM, Symonds TL, Burke C, Mathewson T 1996. Occupational risk factors for the first-onset of low back trouble: a study of serving police officers. Spine; 21: 2612-2620.

Burton AK, Waddell G 1998. Clinical guidelines in the management of low back pain. Bailliere's Clinical Rheumatology; 12: 17-35.

Burton AK, Waddell G, Tillotson KM, Summerton N 1999. Information and advice to patients with back pain can have a positive effect: a randomized controlled trial of a novel educational booklet in primary care. Spine; 24: 2484-2491.

Carey TS, Garrett JM, Jackman AM 2000. Beyond the good prognosis: Examination of an inception cohort of patients with chronic low back pain. Spine; 25: 115-120.

Carosella AM, Lackner JM, Feuerstein M 1994. Factors associated with early discharge from a multidisciplinary work rehabilitation program for chronic low back pain. Pain; 57 : 69-76.

Catchlove R, Cohen K 1982. Effects of a directive return to work approach in the treatment of workman's compensation patients with chronic pain. Pain; 14: 181-191.

Cheadle A, Franklin G, Wolfhagen C 1994. Factors influencing the duration of work-related disability: a population-based study in Washington State Workers Compensation. Am J Public Health; 84: 190-196.

Cherkin DC, Deyo RA, Street JH, Hunt M, Barlow W 1996. Pitfalls of patient education. Limited success of a program for back pain in primary care. Spine; 21: 345-355.

Clinical Standards Advisory Group. Back Pain. Report of a CSAG committee on back pain. 1994. London, HMSO.

Croft, P., Macfarlane, G., Papageorgiou, A. (1998).
Outcome of low back pain in general practice:
A prospective study

British Medical Journal 1998 (May 2); 316 (7141): 1356–1359

Croft PR, Papageorgiou AC, Ferry S, Thomas E, Jayson MIV, Silman AJ 1995. Psychologic distress and low back pain : evidence from a prospective study in the general population. Spine; 20: 2731-2737.

Cutler RB, Fishbain DA, Rosomoff HL, Abdel-Moty E, Khalil TM, Rosomoff RS 1994. Does nonsurgical pain center treatment of chronic pain return patients to work? A review and meta-analysis of the literature. Spine; 19: 643-652.

Daltroy LH, Iversen MD, Larson MG, Lew R, Wright E, Ryan J, Zwerling C, Fossel AH, Liang MH 1997. A controlled trial of an educational program to prevent low back injuries. The New England Journal of Medicine; 337: 322-328.

Davis KG, Heaney CA 2000. The relationship between psychosocial work characteristics and low back pain: underlying methodological issues. Clinical Biomechanics; (in press)

Department of Health 1999. The Prevalence of Back Pain in Great Britain in 1998. Internet, (www.doh.gov.uk/public/backpain.htm).

Devereux JJ, Buckle PW, Vlachonikolis IG 1999. Interactions between physical and psychosocial risk factors at work increase the risk of back disorders; an epidemiological approach. Occupational and Environmental Medicine; 56: 343-353.

Di Fabio RP 1995. Efficacy of comprehensive rehabilitation programs and back school for patients with low back pain : a meta-analysis. Physical Therapy; 75: 865-878.

Dionne CE 1999. Low back pain. in Crombie IK, Croft PR, Linton SJ, LeResche L, Von Korff M (ed). Epidemiology of pain. 283-297. Seattle, IASP Press.

Dishman RK, Oldenburg B, O'Neal H, Shephard RJ 1998. Worksite physical activity interventions. Am J Prev Med; 15: 344-361.

Dueker JA, Ritchie SM, Knox TJ, Rose SJ 1994. Isokinetic trunk testing and employment. Journal of Occupational Medicine; 36: 42-48.

Ehrmann-Feldman D, Rossignol M, Abenhaim L, Gobielle D 1996. Physician referral to physical therapy in a cohort of workers compensated for low back pain. Physical Therapy; 76: 150-157.

Faas A 1996. Exercises: which ones are worth trying, for which patients, and when? Spine; 21: 2874-2877.

Faucett J 1999. Chronic low back pain: Early interventions. Annual Review of Nursing Research; 17: 155-182.

Ferguson SS, Marras WS 1997. A literature review of low back disorder surveillance measures and risk factors. Clinical Biomechanics; 12: 211-226.

Feuerstein M, Zastowny TR 1999. Occupational Rehabilitation: Multidisciplinary Management of Work-Related Musculoskeletal Pain and Disability. in Gatchel R, Turk DC (ed). Psychological Approaches to Pain Management: A Practitioner's Handbook. 458-485. London, The Guildford Press.

Fishbain DA, Cutler R, Rosomoff HL, Khalil TM, Steele-Rosomoff R 1997. Impact of chronic pain patients' job perception variables on actual return to work. Clin J Pain; 13: 197-206.

Fordyce WE, Brockway JA, Bergman JA, Spengler D 1986. Acute back pain: a control group comparison of behavioral -vs- traditional management methods. J Behav Med; 9: 127-140.

Frank J, Sinclair S, Hogg-Johnson S, Shannon H, Bombardier C, Beaton D, Cole D 1998. Preventing disability from work-related low-back pain. New evidence gives new hope - if we can just get all the players onside. Canadian Medical Association Journal; 158: 1625-1631.

Frank JW, Brooker AS, DeMaio SE, Kerr MS, Maetzel A, Shannon HS, Sullivan TJ, Norman RW, Wells RP 1996. Disability resulting from occupational low back pain: Part II: what do we know about secondary prevention? a review of the scientific evidence on prevention after disability begins. Spine ; 21: 2918-2929.

Frank JW, Kerr MS, Brooker AS, DeMaio SE, Maetzel A, Shannon HS, Norman RW , Sullivan TJ, Wells RP 1996. Disability resulting from occupational low back pain: Part I: what do we know about primary prevention? a review of the scientific evidence on prevention before disability begins. Spine; 21: 2908-2917.

Friedrich M, Gittler G, Halberstadt Y, Cermak T, Heiller I 1998. Combined exercise and motivation program: Effect on the compliance and level of disability of patients with chronic low back pain: A randomized controlled trial. Archives of Physical Medicine & Rehabilitation; 79: 475-487.

Frost H, Lamb SE, Klaber-Moffett JA, Fairbank JCT, Moser JS 1998. A fitness programme for patients with chronic low back pain: 2-year follow-up of a randomised controlled trial. Pain; 75: 273-280.

Garcy P, Mayer T, Gatchel RJ 1996. Recurrent or new injury outcomes after return to work in chronic disabling spinal disorders: tertiary prevention efficacy of functional restoration treatment. Spine; 21: 952-959.

Garg A, Moore JS 1992. Epidemiology of low back pain in industry. Occupational Medicine; 7: 593-608.

Garg A, Moore JS 1992. Prevention strategies and the low back in industry. Occupational Medicine; 7: 629-640.

Gebhardt WA 1994. Effectiveness of training to prevent job-related back pain: a meta-analysis. British Journal of Clinical Psychology; 33: 571-574.

Greenwood JG, Harvey HJ, Pearson JC, Woon CL, Posey P, Main CF 1990. Early intervention in low back disability among coal miners in West Virginia: negative findings. Journal of Occupational Medicine; 32: 1047-1052.

Hadler NM 1997. Back pain in the workplace. What you lift or how you lift matters far less than whether you lift or when. Spine; 22: 935-940.

Haig AJ, Linton P, McIntosh M 1990. Aggressive early medical management by a specialist in physical medicine and rehabilitation: effect on lost time due to injuries in hospital employees. Journal of Occupational Medicine; 32: 241-244.

Haldorsen EMH, Indahl A, Ursin H 1998. Patients with low back pain not returning to work: a 12-month follow-up study. Spine; 23: 1202-1208.

Hall H, McIntosh G, Melles T, Holowachuk B, Wai E 1994. Effect of discharge recommendations on outcome. Spine; 19: 2033-2037.

Harris JS 1997. Occupational Medicine Practice Guidelines. Harris JS (ed). Beverly (MA), OEM Press.

Hartigan C 1996. Rehabilitation of acute and subacute low back and neck pain in the work-injured patient. Orthop Clin North Am; 27: 860.

Hazard RG, Haugh LD, Reid S, McFarlane G, MacDonald L 1997. Early physician notification of patient disability risk and clinical guidelines after low back injury. Spine; 22: 2951-2958.

Hiebert R, Skovron ML, Nordin M, Crane M 2000. Work restrictions and outcome of non-specific low back pain. Spine; (in press)

Hoogendoorn WE, van Poppel MNM, Bongers PM, Koes BW, Bouter LM 1999. Physical load during work and leisure time as risk factors for back pain. Scandinavian Journal of Work and Environmental Health; 25: 387-403.

HSE 1998. Manual Handling Operations Regulations 1992: Guidance on Regulations (L23). Norwich, Her Majesty's Stationery Office.

Hunt A, Habeck R 1993. The Michigan Disability Prevention Study. Kalamazoo (MI), W.E Upjohn Institute for Employment Research.

IASP 1995. Back Pain in the Workplace: Management of Disability in Nonspecific Conditions. Fordyce WE (ed). Seattle, IASP Press.

ICSI 1998. Health Care Guideline: Adult Low Back Pain. Internet, Institute for Clinical Systems Integration (www.icsi.org/guide/).

Infante-Rivarde C, Lortie M 1997. Relapse and short sickness absence for back pain in the six months after return to work. Occup Environ Med; 54: 328-334.

Ingermarsson HA, Nordholm L, Sivik T 1997. Risk for long-term disability among patients with back pain. Scandinavian Journal of Rehabilitation Medicine; 29: 205-212.

INSERM 2000. Les lombalgies en milieu professionel: quels facteurs de risque et quelle prevention? (Low back pain at the workplace: risk factors and prevention). Paris, Les editions INSERM. Synthese bibliographique realisee a la demande de la CANAM (in French).

Jarvikoski A, Mellin G, Estlander A, Harkapaa K, Vanharanta H, Hupli M, Heinonen R 1993. Outcome of two multimodal back treatment programs with and without intensive physical training. Journal of Spinal Disorders; 6: 93-98.

Johanning E 2000. Evaluation and management of occupational low back disorders. American Journal of Industrial Medicine; 37: 94-111.

Jones JR, Hodgson JT, Clegg TA, Elliott RC 1998. Self-reported work-related illness in 1995. Results from a household survey. 1-282. Norwich, Her Majesty's Stationery Office.

Kankaanpaa M, Taimela S, Airaksinen O, Hanninen O 1999. The efficacy of active rehabilitation in chronic low back pain: Effect on pain intensity, self-experienced disability, and lumbar fatigability. Spine; 24: 1034-1042.

Kaplansky BD 1998. Prevention strategies for occupational low back pain. Occupational Medicine; 13: 33-45.

Karjalainen K et al 1999. Multidisciplinary rehabilitation for subacute low back pain among working age adults. (Protocol for Cochrane Review). in The Cochrane Library, Issue 4. Oxford, Update Software. (Review submitted).

Kazimirski JC 1997. CMA Policy Summary: The physician's role in helping patients return to work after an illness or injury. Canadian Medical Association Journal; 156: 680A-680C.

Kendall NAS, Linton SJ, Main CJ 1997. Guide to assessing psychological yellow flags in acute low back pain: Risk factors for long-term disability and work loss. 1-22. Wellington, NZ, Accident Rehabilitation & Compensation Insurance Corporation of New Zealand and the National Health Committee.

Klaber-Moffett J, Torgerson D, Bell-Seyer S, Jackson D, Llewelyn-Phillips H, Farrin A, Barber J 1999. Randomised controlled trial of exercise for low back pain: clinical outcomes, costs, and preferences. BMJ; 319: 279-283.

Krause N, Dasinger LK, Neuhauser F 1998. Modified work and return to work: a review of the literature. Journal of Occupational Rehabilitation; 8: 113-139.

Krause N, Ragland DR 1994. Occupational disability due to Low Back Pain: A new interdisciplinary classification based on a phase model of disability. Spine; 19: 1011-1020.

Lahad A, Malter A, Berg AO, Deyo R 1994. The effectiveness of four interventions for the prevention of low back pain. Journal of the American Medical Association; 272: 1286-1291.

Lancourt J, Kettelhut M 1992. Predicting return to work for lower back pain patients receiving workers compensation. Spine; 17: 629-640.

Lehmann TR, Spratt KF, Lehmann KK 1993. Predicting long-term disability in low back injured workers presenting to a spine consultant. Spine; 18: 1103-1112.

Ljunggren AE, Weber H, Kogstad O, Thom E, Kirkesola G 1997. Effect of exercise on sick leave due to low back pain: a randomized, comparative, long-term study. Spine; 22: 1610-1616.

Loisel P, Abenhaim L, Durand P, Esdaile JM, Suissa S, Gosselin L, Simard R , Turcotte J, Lemaire J 1997. A population-based, randomized clinical trial on back pain management. Spine; 22: 2911-2918.

Lonn JH, Glomsrod B, Soukup MG, Bo K, Larsen S 1999. Active back school: Prophylactic management for low back pain: A randomized, controlled, 1-year follow up study. Spine; 24: 865-871.

Macfarlane GJ, Thomas E, Papageorgiou AC, Croft PR, Jayson MIV, Silman AJ 1997. Employment and physical work activities as predictors of future low back pain. Spine; 22: 1143-1149.

Marras WS, Lavender SA, Leurgens SE, Rajulu SL, Allread WG, Farthallah FA, Ferguson SA 1993. The role of dynamic three-dimensional trunk motion in occupationally-related low back disorders: The effects of workplace factors trunk position and trunk motion characteristics on risk of injury. Spine; 18: 617-628.

Masset DF, Piette AG, Malchaire JB 1998. Relation between functional characteristics of the trunk and the occurrence of low back pain: Associated risk factors. Spine; 23: 359-365.

Mitchell RI, Carmen GM 1990. Results of a multicenter trial using an intensive active exercise program for the treatment of acute soft tissue and back injuries. Spine; 15: 514-521.

Moore JE, Von Korff M, Cherkin D, Saunders KLKA 2000. A randomized trial of a cognitive-behavioral program for enhancing back self care in a primary care setting. (manuscript submitted);

Mostardi RA, Noe DA, Kovacik MW, Porterfield JA 1992. Isokinetic lifting strength and occupational injury: a prospective study. Spine; 17: 189-193.

Muller CF, Monrad T, Biering-Sorensen F, Darre E, Deis A, Kryger P 1999. The influence of previous low back trouble, general health, and working conditions on future sick-listing because of low back trouble: A 15-year follow-up study of risk indicators for self-reported sick-listing caused by low back trouble. Spine; 24: 1562-1570.

Nachemson A, Jonsson E 2000. Swedish SBU report. Evidence based treatment for back pain. Stockholm/Philadelphia, Swedish Council on Technology Assessment in Health Care (SBU)/Lippincott (English translation) - (in press).

Nachemson A, Vingard E 2000. Assessment of neck and back pain syndromes. in Nachemson A, Jonsson E (ed). Swedish SBU report. Evidence based treatment for back pain. Stockholm/Philadelphia, Swedish Council on Technology Assessment in Health Care (SBU)/Lippincott (English translation) - (in press).

Nadler SF, Stitick TP, Malanga GA 1999. Optimizing outcome in the injured worker with low back pain. Critical Reviews in Physical and Rehabilitation Medicine; 11: 139-169.

Nassau DW 1999. The effects of prework functional screening on lowering an employer's injury rate, medical costs, and lost work days. Spine; 24: 269-274.

National Research Council 1999. Work-related musculoskeletal disorders: report, workshop summary and workshop papers. Washington, DC, National Acadmey Press (www.nap.edu).

Newton M, Thow M, Somerville D, Henderson I, Waddell G 1993. Trunk strength testing with iso-machines: Part 2: Experimental evaluation of the Cybex II back testing system in normal subjects and patients with chronic low back pain. Spine; 18: 812-824.

Newton M, Waddell G 1993. Trunk strength testing with iso-machines: Part 1: Review of a decade of scientific evidence. Spine; 18: 801-811.

NIOSH 1997. Musculoskeletal Disorders and Workplace Factors. A critical review of epidemiologic evidence for work-related musculoskeletal disorders of the neck, upper-extremity, and low back . Bernard BP (ed). Cincinnati, NIOSH.

Nordin M, Skovron ML, Hiebert R, Weiser S, Brisson PM, Campello M, Harwood K, Crane M, Lewis S 1997. Early predictors of delayed return to work in patients with low back pain. Journal of Musculoskeletal Pain; 5: 5-27.

Norman R, Wells R, Neumann P, Frank J, Shannon H, Kerr M, Ontario Universities Back Pain Study (OUBPS) Group. 1998. A comparison of peak vs cumulative physical work exposure risk factors for the reporting of low back pain in the automotive industry. Clinical Biomechanics; 13: 561-573.

Oleinick A, Gluck JV, Guire KE 1996. Factors affecting first return to work following a compensable occupational back injury. American Journal of Industrial Medicine; 30: 540-555.

Ostry A, Stringer B, Berkowitz J, Schultz I 1999. Workplace organisation questionnaire (poster presentation). Presented to the 9th World Congress on Pain, Vienna, August 1999.

Papageorgiou AC, Macfarlane GJ, Thomas E, Croft PR, Jayson MIV, Silman AJ 1997. Psychosocial factors in the workplace - Do they predict new episodes of low back pain?: Evidence from the South Manchester back pain study. Spine; 22: 1137-1142.

Pfingsten M, Kroner-Herwig B, Harter W, Hempel D, Kronshage U, Hildebrandt J 2000. Fear-avoidance behavior and anticipation of pain in patients with chronic low back pain - a randomised controlled study. Spine (in press);

Pollock RA, Saunders HD, Melnick MS 1991. Your Healthy Back. Chaska, Minnesota, The Saunders Group, Inc.

Polyani MFD, Eakin J, Frank JW, Shannon HS, Sullivan T 1998. Creating healthier work environments: a critical review of the health impacts of workplace organisational change interventions. National forum on health, Canada Health Action: building on the legacy. Quebec; Ste Foy, Editions Multimondes.

Poole CJM 1999. Can sickness absence be predicted at the pre-placement health assessment? Occupational Medicine; 49: 337-339.

Rainville J, Carlson N, Polatin P, Gatchel RJ, Indahl A 2000. Exploration of physicians' recommendations for activities in chronic low back pain. Spine; (in press)

Riihimaki H, Wickstrom G, Hanninen K, Luopajarvi T 1989. Predictors of sciatic pain among concrete reinforcment workers and house painters - a five-year follow-up. Scandinavian Journal of Work and Environmental Health; 15: 415-423.

Roland M, Dixon M 1989. Randomized controlled trial of an educational booklet for patients presenting with back pain in general practice. Journal of the Royal College of General Practitioners; 39 : 244-246.

Royal College of General Practitioners. 1995. The development and implementation of clinical guidelines. Report of the Clinical Guidelines Working Group. 1-31. London, Royal College of General Practitioners

Royal College of General Practitioners 1999. Clinical Guidelines for the Management of Acute Low Back Pain. London, Royal College of General Practitioners (www.rcgp.org.uk).

Ryan WE, Krishna MK, Swanson CE 1995. A prospective study evaluating early rehabilitation in preventing back pain chronicity in mine workers. Spine; 20: 489-491.

Sandstrom J, Esbjornsson E 1986. Return to work after rehabilitation. The significance of the patient's own prediction. Scandinavian Journal of Rehabilitation Medicine; 18: 29-33.

Savage RA, Whitehouse GH, Roberts N 1997. The relationship between the magnetic resonance imaging appearance of the lumbar spine and low back pain, age and occupation in males. European Spine Journal; 2: 106-114.

Scheer SJ, Radack KL, O'Brien Jr DR 1995. Randomized controlled trials in industrial low back pain relating to return to work. Part 1 acute interventions. Archives of Physical Medicine & Rehabilitation; 76: 966-973.

Scheer SJ, Watanabe TK, Radack KL 1997. Randomized controlled trials in industrial low back pain. Part 3 Subacute/chronic interventions. Archives of Physical Medicine & Rehabilitation; 78: 414-423.

Shannon HS, Walters V, Lewchuk W, Richardson J, Moran LA, Haines T, Verma D 1996. Workplace organizational correlates of lost-time accident rates in manufacturing. American Journal of Industrial Medicine; 29: 258-268.

Sinclair SJ, Hogg-Johnson S, Mondloch MV, Shields SA 1997. The effectiveness of an early active intervention program for workers with soft-tissue injuries: The early claimant cohort study. Spine; 22: 2919-2931.

Snook SH, Webster BS 1998. An evidence-based approach for managing low back pain and disability in industry. Project 97-7. Hopkinton, Massachusetts, Liberty Mutual Research Centre.

Snook SH, Webster BS, McGorry RW, Fogleman MT, McCann KB 1998. The reduction of chronic nonspecific low back pain through the control of early morning lumbar flexion. Spine; 23: 2601-2607.

Symmons DPM, van Hemert AM, Vandenbrouke JP, Valkenburg HA 1991. A longitudinal study of back pain and radiological changes in the lumbar spines of middle-aged women.I. Clinical findings. Annals of the Rheumatic Diseases; 50: 158-161.

Symmons DPM, van Hemert AM, Vandenbrouke JP, Valkenburg HA 1991. A longitudinal study of back pain and radiological changes in the lumbar spines of middle-aged women.II. Radiographic findings. Annals of the Rheumatic Diseases; 50: 162-166.

Symonds TL, Burton AK, Tillotson KM, Main CJ 1995. Absence resulting from low back trouble can be reduced by psychosocial intervention at the work place. Spine; 20: 2738-2745.

Szpalski M, Gunzburg R 1998. Methods of trunk function testing. Seminars in Spine Surgery; 10: 104-111.

Tate RB, Yassi A, Cooper J 1999. Predictors of time loss after back injury in nurses. Spine; 24: 1930-1936.

Teasell RW, Harth M 1996. Functional restoration: returning patients with chronic low back pain to work - revolution or fad ? Spine; 21: 844-847.

Turner JA 1996. Educational and behavioral interventions for back pain in primary care. Spine; 21: 2851-2857.

U.S.Preventive Services Task Force 1996. Counselling to prevent low back pain. Internet, National Guidelines Clearing House (www.guideline.gov).

van den Hoogen HMM, Koes BW, van Eijk JTM, Bouter LM 1995. On the accuracy of history, physical examination, and erythrocyte sedimentation rate in diagnosing low back pain in general practice : a criteria-based review of the literature. Spine; 20: 318-326.

van der Weide WE, Verbeek JHAM, van Dijk FJH 1999. Relation between indicators for quality of occupational rehabilitation of employees with low back pain. Occupational and Environmental Medicine; 56: 488-493.

van der Weide WE, Verbeek JHAM, van Dijk FJH, Doef F 1997. An audit of occupational health care for employees with low-back pain. Occupational Medicine; 47: 294-300.

van der Weide WE, Verbeek JHAM, van Tulder MW 1997. Vocational outcome of intervention for low back pain. Scandinavian Journal of Work and Environmental Health; 23: 165-178.

van Doorn JWC 1995. Low back disability among self-employed dentists, veterinarians, physicians and physical therapists in the Netherlands. Acta Orthopaedica Scandinavica; 66 (Suppl 263): 1-64.

van Poppel MNM, Koes BW, Smid T, Bouter LM 1997. A systematic review of controlled clinical trials on the prevention of back pain in industry. Occup Environ Med; 54: 841-847.

van Poppel MNM, Koes BW, van der Ploeg T, Smid T, Bouter LM 1998. Lumbar supports and education for the prevention of low back pain in industry. Journal of the American Medical Association; 279: 1789-1794.

van Tulder MW, Assendelft JJ, Koes BW, Bouter LM 1997. Spinal radiographic findings and nonspecific low back pain: a systematic review of observational studies. Spine; 22: 427-434.

van Tulder MW, Esmail R, Bombardier C, Koes BW 1999. Back schools for non-specific low back pain (Cochrane Review). In: The Cochrane Library, Issue 3. Oxford, Update Software.

van Tulder MW, Goossens M, Waddell G, Nachemson A 2000. Conservative treatment of chronic low back pain. in Nachemson A, Jonsson E (ed). Swedish SBU report. Evidence based treatment for back pain. Stockholm/Philadelphia, Swedish Council on Technology Assessment in Health Care (SBU)/Lippincott (English translation) - (in press).

van Tulder MW, Malmivaara A, Esmail R, Koes BW, Bouter LM 2000. Exercise therapy for low back pain. Cochrane Review (in press);

van Tulder MW, Waddell G 2000. Conservative treatment for acute and subacute low back pain . in Nachemson A, Jonsson E (ed). Swedish SBU report. Evidence based treatment for back pain. Stockholm/Philadelphia, Swedish Council on Technology Assessment in Health Care (SBU)/Lippincott (English translation) - (in press).

Victorian Workcover Authority. 1996. Guidelines for the management of employees with compensable low back pain . Melbourne, Victorian Workcover Authority.

Videman T, Battié MC 1999. The influence of occupation on lumbar degeneration. Spine; 24: 1164-1168.

Vingard E, Nachemson A 2000. Work related influences on neck and low back pain. in Nachemson A, Jonsson E (ed). Swedish SBU report. Evidence based treatment for back pain. Stockholm/Philadelphia, Swedish Council on Technology Assessment in Health Care (SBU)/Lippincott (English translation) - (in press).

Volinn E 1999. Do workplace interventions prevent low-back disorders? If so, why?: a methodologic commentary. Ergonomics; 42: 258-272.

Vroomen PCAJ, de Krom MCTFM, Wilmink JT, Kester ADM, Knottnerus JA 1999. Lack of effectiveness of bed rest for sciatica. The New England Journal of Medicine; 340: 418-423.

Waddell G 1998. The Back Pain Revolution. Edinburgh, Churchill Livingstone.

Waddell G, Feder G, Lewis M 1997. Systematic reviews of bed rest and advice to stay active for acute low back pain. British Journal of General Practice; 47: 647-652.

Waddell G, Feder G, McIntosh A, Lewis M, Hutchinson A 1996. Low back Pain Evidence Review. London, Royal College of General Practitioners.

Waddell G, McIntosh A, Hutchinson A, Feder G, Lewis M 1999. Low back Pain Evidence Review. London, Royal College of General Practitioners (www.rcgp.org.uk).

Waddell G, Waddell H 2000. A review of social influences on neck and back pain and disability. in Nachemson A, Jonsson E (ed). Swedish SBU report. Evidence based treatment for back pain. Stockholm/Philadelphia, Swedish Council on Technology Assessment in Health Care (SBU)/Lippincott (English translation) - (in press).

Westgaard RH, Winkel J 1996. Guidelines for occupational musculoskeletal load as a basis for intervention: a critical review. Applied Ergonomics; 27: 79-88.

Westgaard RH, Winkel J 1997. Ergonomic intervention research for improved musculoskeletal health: A critical review. Industrial Ergonomics; 20: 463-500.

Wiesel SW, Boden SD, Feffer HL 1994. A quality-based protocol for management of musculoskeletal injuries: a ten-year prospective outcome study. Clinical Orthopaedics and Related Research; 301: 164-176.

Wigley RD, Carter N, Woods J, Ahuja M, Couchman KG 1990. Rehabilitation in chronic back pain: employment status after four years. New Zealand Medical Journal; 103: 9-10.

Wilder DG, Pope MH 1996. Epidemiological and aetiological aspects of low back pain in vibration environments - an update. Clinical Biomechanics; 11: 61-71.

Wood DJ 1987. Design and evaluation of a back injury prevention program within a geriatric hospital. Spine; 12: 77-82.

Yamamoto S 1997. Guidelines on Worksite Prevention of Low Back Pain Labour Standards Bureau Notification No.57. Industrial Health; 35: 143-172.

Yassi A, Tate R, Cooper JE, Snow S, Vallentyne S, Khokhar JB 1995. Early intervention for back injuries in nurses at a large Canadian tertiary care hospital: an evaluation of the effectiveness and cost benefits of a two-year pilot project. Occupational Medicine; 45: 209-214.

Zwerling C, Daltroy LH, Fine LJ, Johnston JJ, Melius J, Silverstein BA 1997. Design and conduct of occupational injury intervention studies: a review of evaluation strategies. American Journal of Industrial Medicine; 32: 164-179.