Effect of Inpatient Multicomponent Occupational Rehabilitation Versus Less Comprehensive Outpatient Rehabilitation on Sickness Absence in Persons with Musculoskeletal- or Mental Health Disorders: A Randomized Clinical Trial.

Purpose To assess effects of an inpatient multicomponent occupational rehabilitation program compared to less comprehensive outpatient rehabilitation on sickness absence in persons with musculoskeletal- or mental health disorders. Methods Randomized clinical trial with parallel groups. Participants were individuals 18-60 years old on sick-leave for 2-12 months with a sick-leave diagnosis within the musculoskeletal, psychological or general and unspecified chapters of ICPC-2, identified in a national register. The inpatient program (4 + 4 days) consisted of Acceptance and Commitment Therapy (ACT), physical training and work-related problem-solving including creating a return to work plan and a workplace visit if considered relevant. The outpatient program consisted primarily of ACT (6 sessions during 6 weeks). Both programs were group based. Primary outcome was cumulated number of sickness absence days at 6 and 12 months follow-up. Secondary outcome was time until sustainable return to work. Results 168 individuals were randomized to the inpatient program (n = 92) or the outpatient program (n = 76). We found no statistically significant difference between the programs in median number of sickness absence days at 6 and 12 months follow-up. In the outpatient program 57% of the participants achieved sustainable return to work (median time 7 months), in the inpatient program 49% (log rank, p = 0.167). The hazard ratio for sustainable return to work was 0.74 (95% CI 0.48-1.32, p = 0.165), in favor of the outpatient program. Conclusions This study provided no support that the more comprehensive 4 + 4 days inpatient multicomponent occupational rehabilitation program reduced sickness absence compared to the outpatient rehabilitation program.