Employment opportunities for people with long-term work disability is difficult to determine

This thesis describes the results of PREDIS (PREdicting DISability), a prospective cohort study with one year follow-up on mental disorders and long-term work disability among 375 persons claiming disability benefit after two years of sickness absence at the regional UWV office in Groningen, the Netherlands, in 2008 and 2009. At two moments, respondents were interviewed with the Composite International Diagnostic Interview (CIDI) to provide DSM-IV classifications of mental disorders, and filled in a questionnaire. These data were linked to data obtained from the UWV on disorders certified as cause of disability, disability assessment outcomes and work status.

The PREDIS prospective cohort study identifies persons claiming disability benefit after two years of sickness absence as a vulnerable group. We found a high prevalence of single and comorbid mental disorders that start in early working careers, are for a large part serious, are substantially undetected by insurance physicians assessing the disability benefit claim. Moreover, mental disorders were found to be substantially undertreated in the years preceding the disability assessment. To aid adequate diagnosis by insurance physicians, three short scales were shown to be reliable screeners for poor mental health. To diagnose adjustment disorder, a new interview schedule, the Diagnostic Interview Adjustment Disorder (DIAD), was developed, which was shown to have good initial validity. In our systematic review of the literature we found older age to be a strong predictor of longer duration of disability. In PREDIS, we found poorer mental health at baseline to predict substantial functional improvement after one year. Having work at baseline and being assessed with no or partial work disability were found to predict a positive work status after one year. Contact with a medical specialist was negatively associated with future work status. Despite substantial functional improvement in about one third of disability claimants, only few of them returned to work during follow up. Predictions of this functional improvement either by claimants or by insurance physicians, were hardly better than chance.