Social inequalities in mental health and mortality among refugees and other immigrants to Sweden : epidemiological studies of register data

This thesis aimed to increase knowledge, using population-based registers, of how pre- and post-migration factors and social determinants of health are associated with inequalities in mental health and mortality among refugees and other immigrants to Sweden.

It addressed four research questions: (1) Are there differences in mental health status between refugees and non-refugee immigrants, and could the hypothesised differences explain mental health differences between immigrants from different countries or areas of origin? (2) Do refugee immigrants have higher mortality rates than non-refugee immigrants? (3) Does the combination of general social determinants of health and post-migration factors increase inequalities among men and women in the relative risk of hospitalisation because of depressive disorder? (4) Are there gender differences in how pre- and post-migration factors and social determinants of health are associated with mental health among immigrants?

Study I & II had cross-sectional designs and used logistic regression analysis to study differences in mental health status between refugee and non-refugee immigrants. In Study I, there was a significant difference in poor mental health (measured by prescribed and purchased psychotropic drugs) between female refugees and non-refugees (OR = 1.27; CI = 1.15–1.40) when adjusted for socioeconomic factors. This difference was not present among males. In Study II, refugee men had a higher likelihood of poor mental health than non-refugees and the Swedish born. Female immigrants had a higher likelihood of poor mental health than Swedish-born women. Adjusted for socioeconomic factors, refugees of most origins had a higher likelihood of poor mental health than non-refugees of the same origin. Study III had a cohort design and analysed mortality rates among non-labour immigrants, using Cox regression analysis. Male refugees had a higher relative risk of mortality from cardiovascular disease (HR = 1.53; CI = 1.04–2.24) and external causes (HR = 1.59; CI = 1.01–2.50) than male non-refugees did, adjusted for socioeconomic factors. Study IV had a cohort design, used Cox regression, and included the population with a strong connection to the labour market in 1999 to analyse the relative risk of hospitalisation due to depressive disorder following unemployment. The lowest relative risk of depressive disorder was found among employed Swedish-born men; the highest risk was among foreign-born females who experienced unemployment during follow-up (HR = 3.47; CI = 3.02–3.98).

In conclusion, immigrants, and particularly refugees, have poorer mental health than native Swedes. Refugee men have a higher relative mortality risk for cardiovascular disease and external causes of death than do non-refugees. The relative risk of hospitalisation due to depressive disorder following unemployment was highest among immigrant women. In order to promote mental health and reduce mortality among immigrants, it is important to consider pre- and post-migration factors as well as the general social determinants of health.

List of scientific papers

I. Hollander A-C, Bruce D, Burstrom B, Ekblad S: Gender-related mental-health differences between refugees and non-refugee immigrants—A cross-sectional register-based study. BMC Public Health. 2011, 11(1):180.
https://doi.org/10.1186/1471-2458-11-180

II. Hollander A-C, Bruce D, Burstrom B, Ekblad S: The association between immigrant subgroup and poor mental health—A population-based register study. [Accepted]
https://pubmed.ncbi.nlm.nih.gov/23896844

III. Hollander A-C, Bruce D, Ekberg J, Burstrom B, Borrell C, Ekblad S: Longitudinal study of mortality among refugees in Sweden. International Journal of Epidemiology. 2012, 41(4):1153–1161.
https://doi.org/10.1093/ije/dys072

IV. Hollander A-C, Bruce D, Ekberg J, Burstrom B, Ekblad S: Hospitalisation for depressive disorder following transition to unemployment—Differentials by gender and immigrant status. A population-based cohort study in Sweden. [Manuscript]