Issues to consider for judging overall rating of risk of bias		Study methods and comments	Rating of reporting
Proportion of baseline sample available for analysis	Response rate (i.e. proportion of study sample completing the study and providing outcome data) is adequate.
Attempts to collect information on participants who dropped out	Attempts to collect information on participants who dropped out of the study are described.
Reasons and potential impact of subjects lost to follow‐up	Reasons for loss to follow‐up are provided.
Outcome and prognostic factor information on those lost to follow‐up	Participants lost to follow‐up are adequately described for characteristics of: individual (e.g. age, sex, depression), back pain condition (history of LBP, current functioning), work (type and characteristics of work environment), treatment (type and extent of care received) and social context (compensation status).