FROM:
Am J Ind Med 2021 (May); 64 (5): 323337 ~ FULL TEXT
Jeanne M. Sears PhD, MS, RN | Deborah Fulton-Kehoe PhD, MPH |
Sheilah Hogg-Johnson PhD, MMath
Department of Health Services,
University of Washington,
Seattle, Washington, USA.
Canadian Memorial Chiropractic College,
Toronto, Ontario, Canada.
FROM: Texas Workers' Compensation Report
Background: Roughly 10% of injured workers experience work injuries that result in permanent impairment and a
permanent partial disability (PPD) award. This study aimed to characterize and quantify long-term employment outcomes for injured workers, by the degree of whole body impairment (WBI) and by participation in several workers' compensation (WC)-based return-to-work (RTW) programs.
Methods: A retrospective cohort of 43,968 Washington State workers were followed for up to 10 years after WC claim closure (2009-2017). Degree of impairment was classified as:
(1) no PPD award,
(2) PPD award with WBI < 10%, or
(3) PPD award with WBI ≥ 10%.
State wage files were used to construct employment outcomes for regression, modeling:
(1) time to first RTW,
(2) time to first RTW interruption,
(3) RTW volatility, and
(4) employment gaps.
Results: Wage patterns and employment outcomes differed significantly by the degree of impairment. Compared to other workers, workers with WBI ≥ 10% had delayed RTW, shorter average times to first RTW interruption, and higher rates of both RTW interruptions and quarters without wages. Time to first RTW averaged over a year, increasing with the degree of impairment. About 9% overall-and 27% of workers with ≥10% WBI-had no observed wages after claim closure. In adjusted models, workers with WBI ≥ 10% had significantly poorer employment outcomes, compared to workers with no PPD award (p < 0.001).
Conclusions: State wage files provide an efficient approach to identifying RTW patterns. Workers with permanent impairment were at substantially higher risk of poor employment outcomes. WC-based RTW programs may promote better employment outcomes.
Keywords: Functional Comorbidity Index; disability evaluation; occupational injuries; permanent impairment; permanent partial disability; return to work; unemployment; vocational rehabilitation; workers' compensation.
From the FULL TEXT Article:
INTRODUCTION
In Washington State and across the United States, roughly 10% of all
workers injured at work experience serious work injuries that result
in permanent impairment and a permanent partial disability (PPD)
award. [1] Workers' compensation (WC)-based PPD awards provide
compensation for Work-related permanent impairments that do not
preclude return to work (RTW) but do prevent working at full physical
capacity (e.g., vision or hearing loss, amputation, spinal impairment).
Work-related permanent impairment is associated with longterm
functional disability, pain, and unstable health, all of which may
interfere with timely and sustained RTW. [28] Compared to other
workers, disabled workers have 50% higher unemployment rates,
and they are more likely to work part-time and in entry-level jobs. [9, 10]
Disabled workers may also face negative treatment by managers and
co-workers, lack of accommodation, and discrimination. [1113] Moreover,
workers with permanent impairments are at higher risk for
reinjury [14] and mortality. [15]
Initial RTW does not necessarily indicate successful RTW. After
RTW, many injured workers with permanent impairments face RTW
interruption (i.e., breaks in employment due to reinjury, unstable health,
disability, lay-off, etc.). [2] For example, in an early Ontario-based study of
workers with permanent impairments, 85% of workers were observed
to RTW at least briefly, while only 50% exhibited sustained RTW. [2] A
more recent Australian study, which did not specifically assess permanent
impairment, found that time to sustained RTW was 1.8 times
longer than time to initial RTW (proxied by the cessation of time-loss
payments); further, although 94% of injured workers had RTW at least
briefly, only 79% achieved sustained RTW during the 2-year follow-up
period. [16] Among Canadian workers who were 5064 years of age and
had a permanent impairment, a higher (more severe) impairment rating
was associated with earlier labor force exit. [17]
Employment is a critical social determinant of health, [18, 19] and
sustained RTW after occupational injury or illness is important for
the health and economic stability of workers, as well as for workplace
productivity. Substantial economic disparities for permanently
impaired workers have been documented using a variety of economic
measures, including wage losses (based on unemployment insurance
data), [2022] earnings losses more broadly (based on tax data), [23] and
poverty. [24] Estimates of the magnitude of these disparities vary
substantially by jurisdiction, which may be due in part to the impairment
rating system used, and to jurisdictional variation in benefit
adequacy. [20] Nevertheless, there is consistent evidence that workers
with permanent impairments are economically disadvantaged relative
to the general working population, [24] to matched uninjured
workers, [22] and to injured workers without permanent impairment. [21, 23] The negative economic impact of permanent impairment
may lessen over time, but it persists long-term. For example, a RAND
study of California workers with permanent impairments documented
that earnings for permanently impaired workers in the first
quarter after injury were 60% of earnings for a matched control
group of uninjured workers; at 5 years after injury, earnings
remained only 72% of those for the control group. [22]
Injured workers with permanent impairments account for a large
share of WC-based vocational rehabilitation program participants. [14]
Accumulating evidence suggests that vocational rehabilitation and
other RTW programs affect injured workers in both positive and
negative ways. [5, 2529] Even after vocational retraining to facilitate
RTW, workers disabled by an occupational injury face substantial
employment challenges. [5] A Washington State study found that about
50% of workers who completed a vocational retraining plan RTW
within 2 years, while fewer than 45% of workers with incomplete
plans had RTW nearly 5 years later. [27] However, there is little existing
research on the impact of WC-based programs on employment
outcomes beyond initial RTW, such as sustained RTW and RTW interruption.
To understand how vocational rehabilitation and other
RTW programs can best assist workers, we need to better understand
the impact of these programs on specific employment patterns.
In sum, injured workers often face delayed, temporary, or intermittent
RTW, or may never RTW at all. The primary aim of this
study was to characterize and quantify long-term employment outcomes,
including RTW and subsequent RTW interruption, by the
degree of permanent impairment. To broadly characterize various
attributes of long-term employment patterns, we used several regression
approaches designed to model a set of employment metrics
that were based on the timing, order, volatility, and prevalence of
presence/absence of quarterly wages after WC claim closure. Secondarily,
we explored the potential impact of several WC-based
RTW programs on employment outcomes.
DISCUSSION
In this study, we found that wage patterns and employment outcomes
significantly differed by the degree of impairment. For the
most part, there were monotonic associations between a higher
degree of impairment and poorer employment outcomes; however,
there was little difference between workers with no PPD and
workers with WBI < 10% regarding timing or frequency of RTW interruption.
Workers with WBI ≥ 10% took longer on average to
RTW, and then had shorter average times to the first RTW interruption,
compared to workers in the other two impairment categories.
Workers with WBI ≥ 10% also had the highest frequency of
RTW interruptions and the highest frequency of quarters with no
wages. A higher risk of reinjury among workers with ≥10% WBI may
contribute to their higher risk of RTW interruption. In a previous
related study, workers with ≥10% WBI had an estimated 34% higher
risk of reinjury, compared to workers with no PPD award, based on
adjusted models that accounted for working time at risk. [14]
It is important to note that all workers in this cohort would have
been classified as having RTW, had we used cessation of time-loss
compensation or WC claim closure as a proxy. Yet 8.98% of the
overall cohort, and 27.32% of workers with ≥10% WBI, had no observed
wages after claim closure. Although most workers RTW
within the same calendar quarter that their claim first closed, many
workers experienced lengthy delays before the first RTW. The
average time from first claim closure to first RTW was more than a
year (restricted mean: 4.18 quarters), monotonically increasing with
increasing degree of impairment.
Several recent studies have demonstrated the importance of
characterizing employment trajectories beyond simply measuring
initial RTW, whether that be via measuring time to sustained RTW, [16]
or via using sequence and/or cluster analysis to identify specific
employment patterns. [43, 44] In this cohort, some workers exhibited
intermittent RTW patterns over an extended period; for other
workers, intermittent RTW patterns eventually stabilized into a
longer stretch of either employment or unemployment (Table 3). By
modeling four different employment outcomes in this study (i.e., time
to first RTW, time to first RTW interruption, RTW volatility, employment
gaps), we were able to broadly characterize various attributes
of long-term employment patterns. In adjusted models
(Table 4), workers with WBI ≥ 10% had substantially and significantly
poorer employment outcomes, compared to workers with no PPD
award, for all four modeling approaches. However, findings were
mixed for workers with WBI < 10%. Compared to workers with no
PPD award, workers with WBI < 10% had significantly poorer outcomes
with respect to time to first RTW and employment gaps, but
not with respect to first RTW interruption and RTW volatility. There
may be quite different mechanisms of effect for initial RTW versus
RTW interruption; RTW may depend on the availability of the preinjury
(perhaps modified) job or the ability to be hired into a new job,
while RTW interruption may depend more upon workplace conditions
that support or interfere with sustained RTW, reinjury incidence,
etc. RTW volatility (rate of transitions from periods of
employment to periods of unemployment) is related to the intermittent
nature of RTW, whether due to employment type (seasonal,
temporary), workplace characteristics, or worker/injury characteristics.
Strikingly, as many as 15 RTW interruptions for an individual
worker were observed over 10 years of follow-up. This observation is
even more striking when we consider that these data represented
quarterly intervals, and thus RTW interruptions lasting less than a
calendar quarter would not have been observed.
We found that participation in the Stay at Work program was
associated with significantly and substantially better employment
outcomes, compared to outcomes for those who did not participate.
Employment outcomes for injured workers participating in WC vocational
rehabilitation programs were of particular interest because
nearly 90% of these workers had a Work-related permanent impairment.
Further, the choice of Option 2 was more prevalent among
workers with permanent impairment; 56.7% of the WBI ≥ 10% group
chose Option 2, compared to only 36.6% of those with no PPD award.
Among workers who chose the conventional retraining plan, workers
with permanent impairment were less likely to complete their plan;
38.2% of the WBI ≥ 10% group completed their plan, compared to
more than half (51.7%) of those with no PPD award. Consistent with
findings from an earlier evaluation, [27] completion of a conventional
vocational retraining plan was associated with significantly and substantially
better employment outcomes, compared to outcomes for
those who did not complete their plan. In contrast, we found that
choosing self-directed retraining funds (Option 2) was significantly and
substantially associated with poorer employment outcomes, compared
to choosing a conventional retraining plan (whether completed or not).
In an earlier related study, [14] we found a higher risk of reinjury among
injured workers who: (1) did not complete their approved vocational
retraining plan, compared to those who did; and (2) chose Option 2,
compared to those who chose a conventional retraining plan (the Stay
at Work program was not assessed).
These program-related findings are descriptive and exploratory,
and, at least in part, they likely reflect selection effects into each of
these programs (whether by WC staff, employers, or workers themselves).
However, these findings merit further inquiry into the underlying
mechanisms, especially as these programs operate at the WC
system level and thus could have important impacts on the health and
safety of large numbers of workers. Every year, roughly 300,000 U.S.
workers experience serious work injuries that result in permanent
impairment and a PPD award. [1] However, there has been little systematic
research regarding the impact of WC-based programs on
long-term employment outcomes for workers with permanent
impairments. In a California study, researchers found that RTW programs
led to significant reductions in the duration of workinjury
absences, and that most of that impact was driven by a large improvement
in RTW for injured workers with permanent impairments. [28] Previous research documenting WC benefit inadequacy
demonstrates the importance of promoting good employment outcomes
to minimize workers' economic losses. In a Wisconsin study of
injured workers (19891990), WC benefits for workers with PPD
awards were estimated to cover 83% of 10-year after-tax projected
losses for men, and 63% for women. [21] In a more recent New Mexico
study linking WC claims (19942000) to federal tax data, WC benefits
for workers with PPD awards were estimated to cover 35% of 10-year
after-tax losses for men, and 28% for women. [23]
While our regression models were not specifically designed to assess
other covariates, most had strong associations with employment
outcomes, and the observed associations may provide exploratory
fodder for further research. A higher score on the Functional Comorbidity
Index was significantly associated with poorer employment
outcomes for three of the four modeling approaches, but was not associated
with time to first RTW. This suggests that, for workers with
comorbidities, sustained RTW is more challenging than initial RTW.
Other research has found that injured workers with multiple chronic
comorbidities had significantly higher odds of not working post-injury
and poorer hours and earnings recovery (using state wage data) compared
to those with no chronic comorbidities. [45] Using data from the
Health and Retirement Study, researchers found that workers with
multimorbidity had a higher risk of transitioning to partial retirement
and to full retirement, when compared to workers without chronic
conditions or to those who had just one comorbidity. [46] Our findings
that women, compared to men, had delayed RTW followed by quicker
RTW interruption, along with more quarters with no wages, generally
comport with other studies showing women at higher risk for RTW
interruption [16] and economic losses [21, 23] after work injury. Our findings
that older workers generally exhibited poorer employment outcomes
compared to younger workers, particularly in the upper age categories,
comport with other studies showing older age as a risk factor for both
RTW interruption16 and early retirement after work injury. [17, 47] Higher
pre-injury wages were associated with better employment outcomes.
Other studies have documented that workers with low income before a
work injury are particularly likely to exit the labor force early, [17] are
more vulnerable to poverty, [24] and face a substantially greater risk of
being unable to escape poverty after Work-related permanent
impairment. [24]
Strengths and limitations
Strengths of this study included the large cohort, and identification
of the first-known WC claim filed in Washington State. Assembling
the cohort based on the first-known WC claim allowed for definitive
identification of the PPD rating with the initial injury; for subsequent
claims, the PPD rating can reflect the adjustment of a rating from a
prior injury that caused permanent impairment a circumstance that
would not be clearly distinguishable using the available WC claims
data. Washington State is one of only four states with no private WC
insurers, which facilitates population-based research. [32, 33] In addition,
access to state wage files enabled us to avoid conflating the end of
time-loss compensation with actual RTW, thereby avoiding an inherent
limitation of studies that rely solely on WC claims data and do
not measure employment directly. [16, 4850] Though common practice,
using the end of time-loss compensation as a proxy for RTW leads to
the underestimation of time lost from work. [51] State wage files are an
efficient but underutilized approach for identifying RTW patterns. [52]
This study also had several limitations. First, with respect to the
initial claim closure quarter (Q0), we were unable to determine from
wage files whether the worker was already working when the WC claim
closed, or whether RTW occurred after claim closure but within the
same quarter (up to 3months later). Second, our addition of a small
constant term to the time variable would have no impact on estimates
based on the regression models, but would have a minor impact on
estimates of mean and median times to first RTW. Third, state wage
files do not capture earnings for workers who are self-employed or
work in exempt occupations. [34] A study based on the Current Population
Survey found that self-employment rates were higher among
workers with limitations, compared to workers without limitations, and
the self-employment differential also increased with education and
age.53 Such differential inclusion in wage files may have affected our
estimates for permanent impairment and age subgroups, to an unknown
degree. Finally, all covariates were also based on administrative
data, and thus have measurement limitations. The Functional Comorbidity
Index was almost certainly underestimated, because diagnoses
unrelated to theWC injury may not be reported toWC for billing
purposes. [38] The WBI variable was essentially a lower bound estimate, [8]
and the strength of association between impairment ratings and economic
losses varies by jurisdiction and rating system. [20, 5457] Although
there is evidence that impairment ratings are associated with earnings
losses,56 there is also strong evidence that impairment ratings are inaccurate
representations of work disability and at best explain a small
amount of related earnings losses.54,55,57 This may in part explain the
relatively small and inconsistent directions of effect (along with inconsistent
statistical significance) that we found across the four employment
outcomes, when comparing workers with <10% WBI to workers
with no PPD award.
CONCLUSIONS
Injured workers may face delayed RTW, may RTW temporarily or intermittently,
or may never RTW at all. Though underutilized, state wage
files provide an efficient approach to identifying RTW patterns, and can
be used as an alternative to proxies that overestimate successful RTW,
such as the end of time-loss compensation or WC claim closure. We
found that workers with permanent impairment were at substantially
higher risk of poorer employment outcomes compared to other workers,
and that WC-based vocational rehabilitation and RTW programs
may be useful to promote better employment outcomes.