BACKGROUND & AIMS The population-based epidemiology of Budd-Chiari syndrome (BCS), a rare disease of hepatic venous outflow obstruction, is largely unknown. This study aimed to elucidate the nationwide population-based incidence, prevalence, complications, case fatalities and direct medical cost of BCS in South Korea from 2009 to 2013.

METHODS Using two large data sources, the Health Insurance Review and Assessment Service Claims database and Rare Intractable Disease registration program database in Korea, we identified all patients with BCS who were registered under International Classification of Diseases 10 (code I82.0). The age- and sex-adjusted incidence and prevalence of BCS were calculated with analysis of complications and direct medical costs.

RESULTS A total of 424 patients with BCS were identified in 2009-2013, with a female-to-male ratio of 1.8 and a median age of 51 years old. The average age- and sex-adjusted incidence from 2011 to 2013 was 0.87 per million per year, and the average age- and sex-adjusted prevalence from 2009 to 2013 was 5.29 per million population. Among them, 10.3% accompanied liver cancer and 3.3% underwent liver transplantation. Annual case-fatality rate was 2.8%. Direct medical costs excluding uninsured services for BCS increased by year from 385 720 USD in 2009 to 765 983 USD in 2013.

CONCLUSIONS This is the first population-based study on the epidemiology of BCS in an Asian country, which presented a higher prevalence than in Western studies. It suggests early diagnosis or improved prognosis of BCS in recent years, and clinical features of BCS that differ by geography.