Method: Almost 100% of the population of South Korea is automatically registered as insured or qualified for Medicaid using an automated hospital billing system established throughout the country, since 2005. Hence we used Korean National Health Insurance (NHI) claims data to estimate the prevalence of RA from 2007 to 2009 and the incidence of RA in 2008. Changes in the use of DMARDs for RA during those three years were also documented.
Result: Using only the ICD-10 diagnostic code for RA, estimates for the prevalence of RA in 2007, 2008, and 2009 were 1.4%, 1.3%, and 1.2%, respectively. However, using our predefined operational definition of RA (a prescription for any DMARD or biologic drug with an RA diagnostic code in the same claim), the corresponding prevalence estimates were 0.26%, 0.27%, and 0.28%. The incidence of RA in 2008 was estimated at 42/100,000 in the general population of South Korea. The prevalence of biologic drug use for RA patients in 2007 was 0.84% and increased to 1.91% in 2009. During that period the prevalence of leflunomide use increased from 5.85% to 11.48%.
Conclusion: Use of data gathered nationwide through the NHI yielded estimates of RA prevalence and incidence in South Korea that are comparable to values for other countries in Asia. The use of leflunomide and anti-TNF agents is increasing in South Korea.
Disclosure: Y. K. Sung, None; S. K. Cho, None; C. B. Choi, None; J. H. Kim, None; J. J. Kim, None; J. H. Lee, None; Y. B. Joo, None; S. C. Bae, None.