Lambeek 2010.

Methods	RCT
Participants	134 adults aged 18‐65 years sick listed for at least 12 weeks owing to low back pain
Interventions	Integrated care: consisted of a workplace intervention based on participatory ergonomics, involving a supervisor, and a graded activity programme based on cognitive behavioural principles. Coordination was done by a clinical occupational physician. Usual care: Usual treatment by medical specialist, occupational physician, general practitioner and/or allied health professional
Outcomes	return‐to‐work defined as duration of sick leave due to low back pain in calendar days from the day of randomisation until full return‐to‐work in own or other work with equal earnings for at least four weeks without recurrence, partial or full. Measured at 3,6,9, and 12 months.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Block randomization of four allocations, using a computer generated random sequence table
Allocation concealment (selection bias)	Low risk	For every stratum, an independent statistician carried out the block randomization. A research assistant prepared opaque, sequentially numbered and sealed coded envelopes for each stratum, containing a referral for either the integrated care group or the usual care group.
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors?	Low risk	All patients received a code according to which a research assistant entered all data in the computer. This ensured blinded analysis of the data by the researcher.
Blinding (performance bias and detection bias) All outcomes ‐ patients?	High risk	Patients were not blinded for treatment allocation
Blinding (performance bias and detection bias) All outcomes ‐ care provider?	High risk	Care providers were also not blinded
Incomplete outcome data (attrition bias) All outcomes ‐ drop‐outs?	Low risk	7% loss to follow‐up
Incomplete outcome data (attrition bias) All outcomes ‐ ITT analysis?	Low risk	intention‐to‐treat (ITT) analysis
Selective reporting (reporting bias)	Low risk	No suggestion found
Similarity of baseline characteristics?	Low risk	No significant differences at baseline.
Co‐interventions avoided or similar?	High risk	More co‐interventions in the control group.
Compliance acceptable?	Unclear risk	5 participants did not participate in the integrated care interention. 12 participants received only two elements of the integrated care.
Timing of the outcome assessment similar?	Low risk	Yes, at 3, 6, 9, and 12 months follow up