Table 1

Summary information on the 14 studies that fulfilled all three inclusion criteria^20–³⁷

Reference	Country	Setting	Outcome definition	n	Inclusion time	Follow up time	Analysis	No. of factors	Study design
Abenhaim et al²⁰	CAN	Workers’ comp	⩾180 days off work	1848	Sickness absence <1 week	2 years	Multivariate logistic regression	6	Retrospective
Andersson et al²¹	SWE	General population	Sickness absence	940	Start sickness absence	22 years	Kaplan-Meier curves	2	Retrospective
Burdorf et al²²	NL	Occupational	Sickness absence	222	Start sickness absence	2 years	Multivariate Cox regression	1	Prospective
Butterfield et al²³	USA	Workers’ comp	Absenteeism days	340	Claim opening, >6 physician visits	3 years max.	Multiple linear regression	7	Retrospective
Fransen et al²⁴	NZ	Insurance setting	Compensation status at 3 months	854	After file claim and <2 weeks	3 months	Multivariate logistic regression	35	Prospective
Gatchel et al^25,²⁶	USA	Occupational/orthopaedic clinic	Return to work	421	<6 weeks since injury	1 year	Stepwise logistic regression	14	Prospective
Gluck et al and Oleinick et al^27,²⁸	USA	Work injury database	Return to work	8628	Start of claim	8 weeks	Multivariate Cox regression	9	Retrospective
Goertz²⁹	USA	Work comp/occ physician	Time loss from work	207	<30 days of onset	6 months	ANOVA   >Multivariate regression	9	Retrospective
Hagen and Thune³⁰	NOR	Insurance setting	Duration of work incapacity	89190	After 2 weeks	1 year	Wilcoxon rank sum test/Kruskal Wallis	3	Retrospective
Dasinger et al and Krause et al^31,³²	USA	Workers’ comp	Duration of work disability	433	1 day of temporary disability within 14 days of injury	1–4 years	Multivariate Cox regression	18	Retrospective
Nordin et al³³	USA	Clinical setting	Return to work	162	Within 1 week of onset of pain	?	Multiple logistic regression	13	Prospective
Schultz et al³⁴	CAN	Workers’ comp	Occupational disability	192	Sub acute phase (4–6 weeks)	3 months	Stepwise logistic regression	33	Prospective
van der Weide et al^35,³⁶	NL	Workers/occ physician	Time to RTW	120	>10 days of sickness absence	12 months	Multivariate Cox regression	25	Prospective
van Doorn³⁷	NL	Insurance setting	Time loss from work	1119	<72 hours after onset of disability	13 years	Multivariate Cox regression	5	Retrospective