Epilepsy in immigrants and Swedish-born: A cohort study of all adults 18 years of age and older in Sweden

Abstract

PurposeWe aimed to study the association between country of birth and incident epilepsy in several immigrant groups using Swedish-born individuals as referents. MethodThe study population included all adults aged 18 years and older in Sweden, living and deceased, 6,690,598 in the first-generation and 6,683,125 in the second-generation sub-study. Epilepsy was defined as having at least one registered diagnosis of epilepsy in the National Patient Register. The incidence of epilepsy in different immigrant groups, using Swedish-born as referents, was assessed by Cox regression, expressed as hazard ratios (HRs) and 95 % confidence intervals (CI). The models were stratified by sex and adjusted for age, geographical residence in Sweden, educational level, marital status, and neighbourhood socioeconomic status. ResultsIn the first-generation sub-study, totally 76,541 individuals had at least one registered diagnosis of epilepsy (1.14 % in total; men 1.22 % and women 1.07 %), and in the second-generation study 72,545 (1.09 %; men 1.18 % and women 0.99 %). After adjusting for confounders, in first-generation immigrants compared to their Swedish-born counterparts the incidence was somewhat lower among both men (HR 0.92, 0.90-0.96) and women (HR 0.93, 0.90-0.96), and in the second-generation immigrants among women (HR 0.95, 0.92-0.99) but not men (HR 0.99; 0.96–1.02). Among immigrant groups, a higher incidence of epilepsy was observed among first-generation women from Africa and Iraq, and second-generation men and women from Bosnia, and women from Finland. ConclusionsRisk of epilepsy was lower in immigrants in general compared to the Swedish-born population; but with higher incidence in some specific groups.