WITHDRAWN: Disparities in Somatic Comorbidities among Immigrants and Norwegians with and without Mental Disorders. A National Register Study

Abstract

Background: Comorbidity between mental disorders and somatic diseases is well-documented. At the same time there are large differences in the prevalence of both mental disorders and somatic diseases such as cardiovascular (CVDs), tumours, metabolic and infectious diseases between immigrants and majority populations in receiving countries. However, whether the comorbidity of mental disorders and somatic diseases differs across immigrant groups and the majority population is currently unclear. This study aimed to explore inequalities in the risk relationship between mental disorder and twenty-two somatic diseases, with differences in these associations between the Norwegians, and eight immigrant groups being of particular interest. Methods: This national register study uses information from 3 142 925 Norwegian residents aged 18+ on any diagnosed mental disorder and twenty-two somatic diseases for years 2008-2016, extracted from the Norwegian Patient Registry and linked with demographic information from National Population Registry. Poisson regression models were used to study the association between mental disorder and each of the twenty-two somatic diseases, divided into CVDs, endocrine and metabolic diseases, cancers, infectious and skin diseases. Differences in risk between Norwegians and eight immigrant groups were investigated by introducing interactions between mental disorder and immigrant background to the analysis and were presented as marginal probabilities.Results: Overall, immigrants had a lower or similar risk of the investigated somatic diseases compared to Norwegians, regardless of any diagnosed mental disorder. However, for CVDs, diabetes mellitus and infectious and skin diseases, the relative differences compared to Norwegians were greater among some immigrant groups with mental disorder than those without, i.e., particularly Sub-Saharan African immigrants.Conclusion: To reduce comorbid inequalities between immigrants and Norwegians, a particular focus should be given to somatic diseases such as CVDs, diabetes, and infectious and skin diseases which often cooccur with mental disorders. However, it is important to recognize the probability of underestimation of the studied associations due to lower use of specialist healthcare services among immigrants, and for mental disorders in particular. Future research should aim to investigate the reasons for such inequalities in comorbidity between immigrants and non-immigrants.