Abstract
Introduction Early return-to-work (RTW) after sick leave is considered to support employees' quality of life. Successful RTW requires adequate cooperation between absent employees and their supervisors. This study assesses the effectiveness of an intervention for COoperation regarding RTW between Sick-listed employees and their Supervisors (COSS; i.e. 'conversation roadmap', monitoring of cooperation and, if necessary, extra occupational physician support). Methods In this field study, employees on sick leave for 2-10 weeks, aged 18 up to and including 60, and performing paid labour for at least 12 h per week were included. Terminally ill were excluded. Multivariate regression (correcting for baseline quality of life) was used to compare 6-months follow up data regarding quality of life between the groups. Using Cox regression analyses, time until first-, full-, and sustainable RTW was compared between groups. Results In total 64 employees received COSS or common practice. No significant group differences were found regarding all study outcomes. The COSS group had a higher chance of work resumption than the common practice group. The hazard ratio was 1.39 for first RTW (95 % CI 0.81-2.37), 1.12 for full RTW (95 % CI 0.65-1.93) and 1.10 for sustainable RTW (95 % CI 0.63-1.95). Conclusions COSS has no significant effects. Yet, the results regarding work resumption show a tendency towards effectiveness. Therefore, COSS can be further developed and applied in practice. Researchers should try to prevent some limitations of the present study in future research, for instance by finding a more common research setting.