Sickness absence and disability pension in a cohort of employees initially on long-term sick leave due to psychiatric disorders in Sweden

Background Over the last decade sickness absence and disability pension (DP) due to psychiatric disorders have increased considerably in Western countries. The scientific knowledge base about prognoses for such absences is very limited, but employers and clinicians often predict them to be very long. The aim of this study was to investigate sickness absence and disability pension in a cohort of employees who initially were on long-term sick leave due to psychiatric disorders, with regard to gender, age, socioeconomic status, and previous sickness absence. Methods The cohort included 4,891 employees in Sweden, who, in 1999 were aged 20–61 and had a new sick-leave spell >90 days with a psychiatric disorder. Retrospective and prospective registry data on sickness absence and DP for 1996–2002 were obtained. Logistic regressions were performed to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for having a low, intermediate, or high level of sickness absence (<17, 17–90, and 91–365 days, respectively) or DP in 2002. Results The mean number of sick-leave days per person per year 3 years prior to inclusion was low; 17 days, but had increased to 211 days by 2000. In 2002, 26% had been granted DP, significantly higher rate among men, while a higher rate of the women had long-term sickness absence. Of all 4,891 subjects, 35% had <17 sick-leave days in 2002. The OR of having low, intermediate, or long-term sickness absence decreased with age. The reverse was found for obtaining DP, for which also low socioeconomic status was an independent predictor of an increased risk (OR = 3.40, CI 2.28–5.08). Conclusions Employees with long-term sick leave due to psychiatric disorders did not have a high level of sickness absence in the 3 years prior to inclusion in the study. Also, 3 years after inclusion, only 35% had very low levels of sickness absence, whereas 26% had been granted DP. Employees who were aged 55–61 showed the lowest risk of sick leave but the highest risk of DP. Low SES was a significant predictor of DP in 2002.