Epilepsy in second-generation immigrants: a cohort study of all children up to 18 years of age in Sweden.

Abstract

Our purpose was to study the association between country of birth and incident epilepsy in second-generation immigrants in Sweden. The study population included all children (n=4023149) aged up to 18years in Sweden. Epilepsy was defined as at least one registered diagnosis of epilepsy in the National Patient Register. The incidence of epilepsy, using individuals with Swedish-born parents as referents, was assessed by Cox regression, expressed in hazard ratios (HRs) and 95% confidence interval (95% CI). All models were stratified by sex and adjusted for age, geographical residence in Sweden, educational level, marital status, neighbourhood socioeconomic status and comorbid conditions, also using data from the Total Population Register. A total of 26310 individuals had a registered epilepsy event, i.e. 6.5/1000 (6.6/1000 amongst boys and 6.3/1000 amongst girls). After adjustment, the risk of epilepsy was lower than in children of Swedish-born parents. Amongst girls the significant HR was 0.85 (95% CI 0.81-0.88), but in boys only when adjusting also for comorbidity (HR0.96, 95% CI 0.92-0.99). Amongst specific immigrant groups, a higher incidence of epilepsy was observed amongst boys with parents from Turkey and Africa, but not when adjusting for comorbidity, and a lower risk was observed in many other groups (boys with parents from Latvia, girls with parents from Finland, Iceland, Southern Europe, countries from the former Yugoslavia, and Asia). The risk of epilepsy was lower in second-generation immigrant children compared to children with Swedish-born parents, but with substantial differences between different immigrant groups.