Mortality and major disease risk among migrants of the 1991-2001 Balkan wars to Sweden: A register-based cohort study

Background In recent decades, millions of refugees and migrants have fled wars and sought asylum in Europe. The aim of this study was to quantify the risk of mortality and major diseases among migrants during the 1991-2001 Balkan wars to Sweden in comparison to other European migrants to Sweden during the same period. Methods and findings We conducted a register-based cohort study of 104,770 migrants to Sweden from the former Yugoslavia during the Balkan wars and 147,430 migrants to Sweden from 24 other European countries during the same period (1991-2001). Inpatient and specialized outpatient diagnoses of cardiovascular disease (CVD), cancer, and psychiatric disorders were obtained from the Swedish National Patient Register and the Swedish Cancer Register, and mortality data from the Swedish Cause of Death Register. Adjusting for individual-level data on sociodemographic characteristics and emigration country smoking prevalence, we used Cox regressions to contrast risks of health outcomes for migrants of the Balkan wars and other European migrants. During an average of 12.26 years of follow-up, being a migrant of the Balkan wars was associated with an elevated risk of being diagnosed with CVD (HR 1.39, 95% CI 1.34-1.43, p < 0.001) and dying from CVD (HR 1.45, 95% CI 1.29-1.62, p < 0.001), as well as being diagnosed with cancer (HR 1.16, 95% CI 1.08-1.24, p < 0.001) and dying from cancer (HR 1.27, 95% CI 1.15-1.41, p < 0.001), compared to other European migrants. Being a migrant of the Balkan wars was also associated with a greater overall risk of being diagnosed with a psychiatric disorder (HR 1.19, 95% CI 1.14-1.23, p < 0.001), particularly post-traumatic stress disorder (HR 9.33, 95% CI 7.96-10.94, p < 0.001), while being associated with a reduced risk of suicide (HR 0.68, 95% CI 0.48-0.96, p = 0.030) and suicide attempt (HR 0.57, 95% CI 0.51-0.65, p < 0.001). Later time period of migration and not having any first-degree relatives in Sweden at the time of immigration were associated with greater increases in risk of CVD and psychiatric disorders. Limitations of the study included lack of individual-level information on health status and behaviors of migrants at the time of immigration. Conclusions Our findings indicate that migrants of the Balkan wars faced considerably elevated risks of major diseases and mortality in their first decade in Sweden compared to other European migrants. War migrants without family members in Sweden or with more recent immigration may be particularly vulnerable to adverse health outcomes. Results underscore that persons displaced by war are a vulnerable group in need of long-term health surveillance for psychiatric disorders and somatic disease. Author summary Why was this study done? Understanding the toll of war on the health of migrants is a highly relevant and pressing issue in light of the global humanitarian crisis, with more people than ever affected by forced displacement. The 1991-2001 Balkan wars were marked by war crimes such as genocide, ethnic cleansing, rape, and torture. More than 100,000 adults and children migrated to Sweden from the former Yugoslavia during the Balkan wars. What did the researchers do and find? Using Swedish registry data, we assessed morbidity and mortality among 104,770 migrants to Sweden from former Yugoslavia during the Balkan wars and 147,430 migrants from 24 other European countries immigrating to Sweden from 1991 to 2001. We found that compared to other European migrants, being a migrant of the Balkan wars was associated with an elevated risk of overall psychiatric disorders, particularly post-traumatic stress disorder, along with a reduced risk of suicide and suicide attempt. Being a migrant of the Balkan wars was also associated with being diagnosed with and dying from both cancer and cardiovascular disease. Later migration to Sweden and having no first-degree relatives in Sweden at immigration was associated with the greatest risk elevation of psychiatric disorders and cardiovascular disease among migrants fleeing armed conflict. What do these findings mean? These findings indicate that being a war migrant may be associated with considerable elevations in post-traumatic stress disorder as well as risks of cardiovascular- and cancer-related morbidities and mortality, particularly among those migrating late in the wars and without family members. War migrants are a particularly vulnerable group that health professionals should monitor over the long term. Host countries should make availability and accessibility of healthcare and social services to war migrants a priority. Potential limitations of this study include lack of information about health status at the time of immigration as well as behavioral factors possibly contributing to increased disease risk such as smoking and alcohol consumption.