Health-related effects of early part-time sick leave due to musculoskeletal disorders: a randomized controlled trial.

OBJECTIVE: Previously we reported that early part-time sick leave enhances return to work (RTW) among employees with musculoskeletal disorders (MSD). This paper assesses the health-related effects of this intervention. METHODS: Patients aged 18-60 years who were unable to perform their regular work due to MSD were randomized to part- or full-time sick leave groups. In the former, workload was reduced by halving working time. Using validated questionnaires, we assessed pain intensity and interference with work and sleep, region-specific disability due to MSD, self-rated general health, health-related quality of life (measured via EuroQol), productivity loss, depression, and sleep disturbance at baseline, 1, 3, 8, 12, and 52 weeks. We analyzed the repeated measures data (171-356 observations) with the generalized estimating equation approach. RESULTS: The intervention (part-time sick leave) and control (full-time sick leave) groups did not differ with regard to pain intensity, pain interference with work and sleep, region-specific disability, productivity loss, depression, or sleep disturbance. The intervention group reported better self-rated general health (adjusted P=0.07) and health-related quality of life (adjusted P=0.02) than the control group. In subgroup analyses, the intervention was more effective among the patients whose current problem began occurring <6 weeks before baseline and those with ≤30% productivity loss at baseline. CONCLUSIONS: Our findings showed that part-time sick leave did not exacerbate pain-related symptoms and functional disability, but improved self-rated general health and health-related quality of life in the early stage of work disability due to MSD.