Table 3. Characteristics of outcomes.
| Study | Follow-up | Return to work outcomes (definition); patient reported outcomes (assigned outcome group) |
| Bültmann 2009 | 12 months | RTW 1 : proportion at work at end of study16, sickness absence (mean number of work days off including all episodes of sick leave); PROs 17,18 : pain during last month (pain), Oswestry Low Back Pain Disability Questionnaire (general function); Not analysed: pain during last week (n.r.) |
| Davey 1994 | 6 months | RTW 2 : proportion at work (full or part time), proportion ever returned to work (full or part time); PROs 17 : Hospital Anxiety and Depression Scale5 (depression), Nottingham Health Profile (physical and social function)5; Not analysed: self-rated anxiety |
| Donceel 1999 | 12 months | RTW 4 : proportion at work at end of study (full time) = proportion ever returned to work, time until RTW6 (full-time, “stable” at end of follow up) |
| Feuerstein 2003 | 16 months | RTW 1: time until RTW7,8,9,10, 11 (full time), proportion ever returned to work (full time) 8,10, 11; PROs 17 : Patient satisfaction, Upper extremity function scale7 (pain), SF-127 (physical and mental function); Not analysed: Levine symptom scale (overlap with other functional scales) |
| Lambeek 2010 | 12 months | RTW 3 : time until RTW (full-time, for at least 4 weeks), proportion ever returned to work8, sickness absence (mean number of work days off including all episodes of sick leave); PROs: Roland disability questionnaire (physical function)18, visual analogue scale (pain)18, EQ5D (general function)7,17 |
| Lindh 1998 | 60 months12 | RTW 1 : proportion at work at end of study8,10,12, 13 (full or part time), proportion ever returned to work8,10,12,13 (full or part time) |
| Purdon 2006 | 20 to 36 weeks | RTW 2 : proportion at work at end of study, proportion ever returned to work (full-time, for at least 2 weeks14); PROs 17 : SF-36 (physical, mental and social function, pain, general health); Not analysed: Hospital Anxiety and Depression Scale15, cumulative sickness absence15, cumulative Incidence of RTW for a spell of 13 weeks14; SF-36 (physical role, emotional role, energy/fatigue), self-assessed general health, health improvement |
| Rossignol 2000 | 6 months | RTW 1 : time until RTW (full or part time, for at least 2 days)11; PROs 18 : visual analogue scale (pain), Quebec Back Pain Disability Scale (physical function), Oswestry low back pain disability questionnaire (overall function); Not analysed: Dallas pain questionnaire (overlap with other functional scales), Health care satisfaction (n.r.) |
| Van der Feltz-Cornelis 2010 | 6 months | RTW 3 : time until RTW (full-time, for at least 4 weeks, all who returned stayed at work)8,10,13, proportion at work at end of study10,13 = proportion ever returned to work10,13; PROs 18 : PHQ9 (depression); Not analysed: PHQ15, SCL-90 (no subscales reported), EQ5D (reported in Quality Adjusted Life Years) |
RTW = return to work, PROs = patient reported outcomes, n.r. = not reported.
Data source: 1administrative data,
diary, interview, or survey, 3combination of diary or interview and administrative data,
not reported.
SD not reported. We imputed missing standard deviations (SDs) with the weighted average of the SDs of the remaining trials.
Hazard ratio estimated from log-rank test.
From personal correspondence.
Data extracted from graph.
Time between a claimant’s initial evaluation by a case manager (not randomization) and RTW.
Missing or unclear number of participants.
Cessation of disability benefits as surrogate for RTW (Rossignol, Feuerstein).
Data presented for two subgroups (immigrant and swedes) which we recombined. Only the number of patients who started the intervention reported. To prevent attrition bias at 60 month, we used 18 month data (ensuring a slightly longer follow up than other studies) and conducted sensitivity analysis using 15 or 12 months.
Data in graph conflicting with text or table.
RTW for at least 2, 6 or 13 weeks reported. We disregarded the 13 weeks outcome which most participants could not achieve due to short follow-up. To ensure longest follow-up, we used 2 weeks and conducted sensitivity analysis using 6 weeks.
Data presented in groups, variance not estimable.
Full-time and part-time RTW reported separately. We used full time RTW and conducted sensitivity analyses using part-time combined with full-time.
End scores.
Change scores.