1217The prevalence of post-traumatic stress disorder in Syrian refugees increased after long-distance migration

Background Refugees are forced migrants but there is a large variation in the distance that refugees cover. Previous studies suggest an inverse association between long-distance migration and self-reported health in the general population but there is a knowledge gap in the health effects of migration in refugee populations. Here, we estimate the association between long-distance migration and post-traumatic stress disorder (PTSD), a severe mental health disorder associated with deteriorating mental and somatic health. Methods Included were 712 adult Syrian refugees and asylum seekers newly arrived in Lebanon and Denmark. PTSD was assessed using the Harvard Trauma Questionnaire, confounding was handled by propensity score-weighting with covariates age, sex, socioeconomic status, trauma experience, and WHO-5-score after multiply imputing missing data, and the 95-percentile confidence interval (CI) was computed by bootstrapping. Results The prevalence of PTSD was high in both Lebanon (55%) and Denmark (60%). After adjusting for biases the prevalence difference increased to 9 percentage point (95-percentile CI: [-1; 19] percentage point). All sensitivity analysis produced estimates of the same magnitude and direction, except when grossly violating the assumption of multiple imputation which halved the magnitude of the association. Conclusions Long-distance migration was associated with an estimated 87 additional cases of PTSD for every 1000 Syrian refugees. This is a first step in examining the effects of migration in refugee health. Key messages Long-distance migration was positively associated with prevalence of post-traumatic stress disorder in Syrian refugees.