Background Despite the increasing pattern of sick leave associated with depression in western countries, little is known about future work disability patterns among such sickness absentees. Aim To identify work disability (sick leave and disability pension) trajectories after the 21st day of a sick-leave spell due to depressive episode, and to investigate sociodemographic and morbidity characteristics of individuals in different trajectory groups. Methods This is a prospective cohort study using Swedish nationwide register data. We studied future work disability days (mean net days of sick leave and disability pension per month) among all individuals with a new sick-leave spell due to depressive episode (ICD-10 F32) ≥ 21 days during the first 6 months of 2010 (n = 10,327). Using group-based trajectory modeling, we identified work disability trajectories for the following 13 months. BIC value, group sizes, and average group probability were used to determine number of trajectories. Sociodemographic and morbidity characteristics were compared by χ2 tests. Results We identified six trajectories of work disability: "decrease to 0 after 4 months" (43% of the cohort); "decrease to 0 after 9 months" (22%); "constant high" (11%); "decrease, then high increase" (9%); "slow decrease" (9%); and "decrease, then low increase" (6%). Those in the groups "constant high" and "decrease then high increase" were older and had the highest proportion with sick leave the year before. Conclusion A majority of the cohort (65%) had no work disability by the end of follow up. Sociodemographic and morbidity characteristics differed between trajectory groups among people on sick leave due to a depressive episode.
Keywords: Depression; Group-based trajectory modelling; Sick leave.