Effects of Inpatient Occupational Rehabilitation vs. Outpatient Acceptance and Commitment Therapy on Sick Leave and Cost of Lost Production: 7-Year Follow-Up of a Randomized Controlled Trial

Previously, we reported that an inpatient multimodal occupational rehabilitation program (I-MORE) was more effective than outpatient Acceptance and Commitment Therapy (O-ACT) in reducing sickness absence and was cost-effective over a 24-month period. Here we present 7-years of follow-up on sick leave and the cost of lost production. We randomized individuals aged 18–60, sick-listed due to musculoskeletal or mental health disorders to I-MORE (n = 82) or O-ACT (n = 79). I-MORE, lasting 3.5 weeks, integrated ACT, physical training, and work-related problem-solving. In contrast, O-ACT mainly offered six weekly 2.5 h group sessions of ACT. We measured outcomes using registry data for days on medical benefits and calculated costs of lost production. Our analysis included regression analyses to examine differences in sickness absence days, logistic general estimating equations for repeated events, and generalized linear models to assess differences in costs of lost production. Unadjusted regression analyses showed 80 fewer days of sickness absence in the 7-year follow-up for I-MORE compared to O-ACT (95