Prevalence, incidence, and mortality of sarcoidosis in Korea, 2003-2015: A nationwide population-based study.

BACKGROUND:The prevalence and incidence of sarcoidosis, a granulomatous disorder involving multiple organ systems, varies among geographical regions and ethnicities. This study evaluated the incidence, prevalence, and mortality of sarcoidosis in a large nationwide population-based cohort in Korea. METHODS:We used data of the National Health Insurance Service database, which is an extensive health-related database including most Korean residents. Adults with a primary diagnosis of sarcoidosis, as determined by International Classification of Disease-Tenth Revision coding (D86), were identified between 2003 and 2015. The incidence, prevalence, and mortality of sarcoidosis were analysed by sex and age. RESULTS:A total of 6376 individuals had a primary diagnosis of sarcoidosis. Their mean age was 48.8 years, and 58.6% were women. The age-adjusted incidence and prevalence of sarcoidosis were 1.3 and 3.4 per 100,000 population respectively; both tended to increase between 2003 and 2015. The all-cause mortality rate was 13.1 per 1000 sarcoidosis patients. The standardised mortality ratio of sarcoidosis patients to the general population was 1.7 (95% confidence interval, 1.5 to 1.8). CONCLUSIONS:This is the largest epidemiologic study of sarcoidosis in an Asian population to date. In Korea, the annual incidence and prevalence of sarcoidosis were relatively low but tended to increase over the 13 years of the study period. Importantly, the overall mortality rate of patients with sarcoidosis was higher than that of the general population.