Table 2

Characteristics of included studies by reporting on AEs

	Overall (n=154), n (%)	Reports on AE (n=94), n (%)	Does not report on AE (n=60), n (%)
ICMJE journal
Published in ICJME journal	53 (34.4)	33 (35.1)	20 (33.3)
Risk of bias
Low risk	13 (8.4)	10 (10.6)	3 (5.0)
Some concerns	47 (30.5)	29 (30.9)	18 (30.0)
High risk	94 (61.0)	55 (58.5)	39 (65.0)
Impact factor
Upper tertile	47 (30.5)	36 (38.3)	11 (18.3)
Middle tertile	54 (35.1)	37 (39.4)	17 (28.3)
Lower tertile	53 (34.4)	21 (22.3)	32 (53.3)
Spinal region
Cervical	24 (15.6)	17 (18.1)	7 (11.7)
Thoracic	33 (21.4)	15 (16.0)	18 (30.0)
Lumbopelvic	28 (18.2)	13 (13.8)	15 (25.0)
Mixed/unclear	69 (44.8)	49 (52.1)	20 (33.3)
Type of practitioner
Chiropractor	36 (23.4)	29 (30.9)	7 (11.7)
Osteopath	15 (9.7)	6 (6.4)	9 (15.0)
Physiotherapist	63 (40.9)	35 (37.2)	28 (46.7)
Medical practitioner	9 (5.8)	4 (4.3)	5 (8.3)
Mixed/other/unclear	31 (20.1)	20 (21.2)	11 (18.3)
Sample size spinal manipulation group*
Upper tertile	51 (33.3)	40 (42.6)	11 (18.6)
Middle tertile	50 (32.7)	28 (29.8)	22 (37.3)
Lower tertile	52 (34.0)	26 (27.7)	26 (44.1)

*One study with unclear sample size excluded.

AE, adverse event;