| Study | Participants employees at start of study? | Participants work disabled because of MI or cLBP at start of study? | Follow-up ⩾1 year? | Loss to follow-up ⩽20% | Adjustment for other prognostic factors? | Justification for used set of prognostic factors? | Total |
| Froom et al 199910 | Yes | Yes | Yes | Yes | Yes | Yes | 6 |
| Boudrez and de Backer 200011 | Yes | Yes | Yes | Yes | Yes | Yes | 6 |
| Hansson and Hannsson 200012 | Yes | Yes | Yes | Yes | Yes | Yes | 6 |
| Van der Giezen et al 200013 | Yes | Yes | Yes | Yes | Yes | Yes | 6 |
| Nielsen et al 200414 | Yes | Yes | Yes | Yes | Yes | Not mentioned | 5 |
| Hamalainen et al 200415 | Yes | Yes | Yes | Not mentioned | Yes | Yes | 5 |