Depression-related work disability: socioeconomic inequalities in onset, duration and recurrence.

Objective: Depression is a major cause of disability in working populations and the reduction of socioeconomic inequalities in disability is an important public health challenge. We examined work disability due to depression with four indicators of socioeconomic status.

Methods: A prospective cohort study of 125 355 Finnish public sector employees was linked to national register data on work disability (>9 days) due to depressive disorders (International Classification of Diseases, codes F32-F34) from January 2005 to December 2011. Primary outcomes were the onset of work disability due to depressive disorders and, among those with such disability, return to work after and recurrent episodes of work disability due to depression.

Results: We found a consistent inverse socioeconomic gradient in work disability due to depression. Lower occupational position, lower educational level, smaller residence size, and rented (vs. owner-occupied) residence were all associated with an increased risk of work disability. Return to work was slower for employees with basic education (cumulative odds ratio = 1.21, 95% CI: 1.05-1.39) compared to those with higher education. Recurrent work disability episodes due to depression were less common among upper-grade non-manual workers (the highest occupational group) than among lower-grade non-manual (hazard ratio = 1.16, 95% CI: 1.07-1.25) and manual (hazard ratio = 1.14, 95% CI: 1.02-1.26) workers.

Conclusions: These data from Finnish public sector employees show persistent socioeconomic inequalities in work disability due to depression from 2005 to 2011 in terms of onset, recovery and recurrence.