Nationwide epidemiological characteristics of chronic fatigue syndrome in South Korea

Chronic fatigue syndrome (CFS) is a long-term disabling illness accompanied by medically unexplained fatigue. This study aimed to explore the epidemiological characteristics of CFS in South Korea. Using the nationwide medical records provided by the Korean Health Insurance Review & Assessment Service (HIRA), we analyzed the entire dataset for CFS patients diagnosed by physicians in South Korea from January 2010 to December 2020. The annual mean incidence of CFS was estimated to be 44.71 ± 6.10 cases per 100,000 individuals [95% CI: 40.57, 48.76], and the prevalence rate was 57.70 ± 12.20 cases per 100,000 individuals [95% CI: 49.40, 65.79]. These two rates increased by 1.53- and 1.94-fold from 2010 to 2020, respectively, and showed an increasing trend with aging and an approximately 1.5-fold female predominance. This study is the first to report the nationwide epidemiological features of CFS, which reflects the clinical reality of CFS diagnosis and care in South Korea. This study will be a valuable reference for studies of CFS in the future.