Effectiveness of guideline-based care by occupational physicians on the return-to-work of workers with common mental disorders: design of a cluster-randomised controlled trial

Background: Sickness absence due to common mental disorders (such as depression, anxiety disorder, adjustment disorder) is a problem in many Western countries. Long-term sickness absence leads to substantial societal and financial costs. In workers with common mental disorders, sickness absence costs are much higher than medical costs. In the Netherlands, a practice guideline was developed that promotes an activating approach of the occupational physician to establish faster return-to-work by enhancing the problem-solving capacity of workers, especially in relation to their work environment. Studies on this guideline indicate a promising association between guideline adherence and a shortened sick leave duration, but also minimal adherence to the guideline by occupational physicians. Therefore, this study evaluates the effect of guideline-based care on the full return-to-work of workers who are sick listed due to common mental disorders. Methods/design: This is a two-armed cluster-randomised controlled trial with randomisation at the occupational physician level. During one year, occupational physicians in the intervention group receive innovative training to improve their guideline- based care whereas occupational physicians in the control group provide care as usual. A total of 232 workers, sick listed due to common mental disorders and counselled by participating occupational physicians, will be included. Data are collected via the registration system of the occupational health service, and by questionnaires at baseline and at 3, 6 and 12 months. The primary outcome is time to full return-to-work. Secondary outcomes are partial return-to-work, total number of sick leave days, symptoms, and workability. Personal and work characteristics are the prognostic measures. Additional measures are coping, self-efficacy, remoralization, personal experiences, satisfaction with consultations with the occupational physician and with contact with the supervisor, experiences and behaviour of the supervisor, and the extent of guideline adherence. Discussion: If the results show that guideline- based care in fact leads to faster and sustainable return-to-work, this study will contribute to lowering personal, societal and financial costs