Differences in predictors of permanent work disability between immigrants and natives: a cohort study of adults with sick leave due to common mental disorders

Objectives: Immigrants with common mental disorders (CMDs) are reported to have a higher risk of disability pension (DP) compared with native residents; however, the reasons for this are not fully understood. This study aimed to investigate (1) differences in morbidity (3 measures) and socioeconomic status in native Swedes, `Western' and `non-Western' immigrants with CMDs and (2) interactions between morbidity and socioeconomic status and immigrant status regarding subsequent DP. Design: The study was a prospective populationbased cohort study using national register data. Crude and multivariate HRs with 95% CIs were calculated using the Cox regression (2007-2010). Participants: All individuals aged 18-59 with an incident sick-leave spell due to CMDs during 2006 were included in the study (N= 66 097). The study population was divided into 3 groups based on country of birth: (1) Sweden, (2) immigrants from `Western' countries (EU25, Norway, Iceland, North America and Oceania) and (3) immigrants from `non-Western' countries (east Europe, Africa, Asia and South America). Results: Particularly, immigrants born in non-Western countries had higher levels of morbidity and lower socioeconomic status than natives (P > 0.001). No significant differences in the associations between specialised psychiatric and somatic care with regard to subsequent DP were found between immigrants and native Swedes. Being prescribed more than 1 type of psychiatric medication was associated with higher HRs for DP in immigrants from Western (HR 3.34; CI 2.3 to 4.9) and non-Western countries (3.6; 1.9 to 6.4) than in native Swedes (2.55; 2.3 to 2.8) (pinteraction= 0.003). Low education was a marginally stronger predictor for DP in non-Western immigrants than in native Swedes and Western immigrants (pinteraction= 0.03). Conclusions: Morbidity measured by medication, but not by specialised healthcare, was a stronger predictor for DP in immigrants than in native Swedes, warranting scrutiny of differences in care and treatment in immigrants and native Swedes with CMDs.