Table 2 Characteristics of the included studies

Study	Country	n	Outcomes	Time between onset and baseline	Follow-up(weeks)	Sample
Boersma and Linton28	SWE	185	>15 Days sick leave	<3 Months	52	Seeking care for non-chronic neck or back pain
Cats-Baril and Frymoyer21	USA	232	Employed or not at 6 months	<3 Months	26	New episodes attending two secondary-care clinics
Coste et al22	FRA	75	RTW or not at 15, 30, 60 and 90 days	<72 h	12	Self-referring to primary care, no radiation below gluteal fold
Deyo and Diehl29	USA	61	Employed or not at 3 months	78% <1 month	12	Clinical trial of bed-rest strategies at outpatient clinic of public hospital. Seeking compensation at baseline excluded.
Dionne et al30	CAN	860	RTW in good health (4 categories)	Mean 70.8 (SD 490) days	104	First time, recurrent and persistent LBP in primary care setting
Fritz et al26 27	USA	77	RTW with or without restrictions at 4 weeks	Mean 5.5 (SD 4.6) days	4	Clinical trial comparing different PT approaches for acute, work-related LBP. Recruited from occupational care providers
Gatchel et al31	USA	227	Disabled or not disabled at 1 year	<6 Weeks	52	Seeking care at orthopaedic or industrial medicine clinic
Hagen et al32	NOR	457	RTW (full duties) or not at 3 and 12 months	8–12 Weeks of sick leave	52	Sick-listed for 8–12 weeks identified from database
Haldorsen et al33	NOR	260	RTW or not at 3, 6 and 12 months	8–12 Weeks	52	Sick leave for 8–12 weeks referred by national insurance office
Hazard et al34	USA	163	Working or not due to LBP at 3 months	<15 Days	12	Work-related injuries identified by Department of Labour and Industry database
Infante-Rivard and Lortie35	CAN	291	RTW or not, duration of time off work	81% <30 days	>104	Referrals to rehabilitation centre
Karjalainen et al36	FIN	156	Duration of sick leave (0, 1–30, >30 days) at 12 months	4–12 Weeks	52	RCT comparing interventions for subacute LBP, recruited from primary care clinics
Klenerman et al25	ENG	123	Pain preventing work attendance or not at 12 months	<1 Week	52	Seeking care at general practice for first or new episode
Lanier and Stockton37	USA	104	Number of lost working days at 6 and 12 weeks	<28 Days	12	Seeking care at family practice
Lehmann et al24	USA	55	Able to RTW or not at 6 months, time to RTW	Mean 27.5 days work absence	26	Referred by occupational physician if between 2 and 6 weeks work absence
Nordin et al38	USA	162	>28 days lost work time or not	<1 Week	4	Employees of New York City Transit Authority, first episode
Ohlund et al39	SWE	103	Duration of sick leave up to 2 years after inclusion. Return to same job at least half time or not.	<7 Weeks of absence	104	Employees of car manufacturer identified on database
Schultz et al (2004)40	CAN	159	RTW or not at 3 months. Number of days lost in 18 months	4–6 Weeks	78	Identified on workers’ compensation database
Schultz et al (2005)46	CAN	100	RTW or not at 3 months	4–6 Weeks	12	Identified on workers’ compensation database
Shaw et al42	USA	291	Return to work (modified, alternate or full duty) or not at 1 month	<14 Days	4	Referral to occupational health clinic by employer or hospital
Steenstra et al23	NL	596	Duration of work absence	<2 Days	26	Identified on occupational health service database at a university hospital
Truchon and Cote43	CAN	321	RTW or not at 6 months	3–12 Weeks	26	Identified on workers’ compensation database
Turner et al44	USA	1068	Number of days of wage replacement at 6 months	Mean 21 (SD 9.7) days	26	Identified on workers’ compensation database
Van der Weide et al45	NL	116	Time to return to same number of hours over 1 year	Mean 18 (SD 6.3) days sick leave	52	Occupational health services for health care and university workers

LBP, low back pain; PT, physiotherapy; RCT, randomised controlled trial; RTW, return to work.