| Sample | |
| S1 | Study provided clearly defined inclusion and exclusion criteria |
| S2 | The stage when initial measures were applied was clearly stated |
| S3 | Measures were applied at an appropriate stage to investigate the research question |
| S4 | The study used representative sampling techniques |
| S5 | Important characteristics of the sample were described |
| S6 | The setting and study site were clearly described |
| Prognostic indicators | |
| PI1 | Clearly defined constructs of what is measured were provided |
| PI2 | Justification of the measures used was given |
| PI3 | The selection of prognostic indicators recognises the multifactorial nature of RTW |
| PI4 | The study used standardised, psychometrically sound instruments for all measures taken |
| Analysis | |
| A1 | Multivariate techniques were used to adjust for potential confounding variables |
| A2 | The analysis avoided over-fitting the data |
| A3 | Prospective validation in another cohort was performed |
| Follow-up | |
| FU1 | RTW outcome was defined in detail, or measure was of sick leave duration |
| FU2 | The duration of follow-up was greater than or equal to 6 months |
| FU3 | The data were complete for at least 80% of the sample measured at baseline |
| FU4 | Outcome measurements were blinded |
Requirements to satisfy quality criteria are available from the corresponding author on request. RTW, return to work.