Beliefs About Working with Health Problems and Support at Work as Predictors of Sick Leave at Post-treatment and at Follow-Up: Secondary Analyses of a Randomised Controlled Trial with Registry Data.

PURPOSE: This study investigates the predictive value of the newly identified factors Beliefs about working with health problems and Support at work for patients on sick leave due to common mental disorders. The aim was to explore the validity of the two factors in a new sample, investigating the factor structure, reliability and construct validity. Further the predictive value was assessed from pre-to post-treatment and at 6- and 12-months follow-up using sick leave data from national registries. METHODS: The study had a longitudinal design conducting secondary analyses with data from a randomised controlled trial (N = 236). The patients filled out self-report questionnaires and sick leave data were collected from national registries. RESULTS: The principal component factor analysis identified the two factors, Beliefs about working with health problems and Support at work, with strong internal consistency α = 0.79 and 0.85 respectively. At pre-to post-treatment both factors separately predicted number of days on sick leave. Beliefs about working with health problems also predicted number of days on sick leave from post-treatment to 6- and 12-months follow-up. CONCLUSION: These findings highlight key predictors for return to work. Beliefs about working with health problems is especially important, predicting up to 12-months post-treatment. These factors can easily be assessed and addressed in therapy and increased focus may help more patients return to work.