Methodological components.

RTW = return to work, PRO = patient reported outcomes, Y = yes, (Y) = probably Yes, N = No, (N) = probably no, ? = unclear, n.a. = not applicable.
1Participants analysed in the group to which they were initially assigned.
2“No” if protocol published and all outcomes correctly reported; “?” if no protocol published and selective reporting not obvious.
3From personal correspondence.
4Participants were probably not aware of the intervention.
5RTW-outcomes not published, incomplete outcome information (see table 3).
6Results presented in subgroups, incomplete outcome information (see table 3).
7Primary outcome not mentioned in protocol.
8Incomplete outcome information (see table 3).
9Cluster randomised trials: No risk of recruitment bias. Baseline information of individual clusters not reported. Effects of RTW-outcomes not corrected for possible design effects (risk of inflated precision).