103 - Prevalence and Incidence of Rheumatoid Arthritis in South Korea

Sunday, November 6, 2011: 9:00 AM-6:00 PM
Hall F2 - Poster Hall (McCormick Place West)
Yoon-Kyoung Sung1, Soo-Kyung Cho1, Chan-Bum Choi1, Jae Hoon Kim2, Jin Ju Kim2, Joo-Hyun Lee2, Young Bin Joo2 and Sang-Cheol Bae1, 1Hanyang University Hospital for Rheumatic Diseases, Clinical Research Center for Rheumatoid Arthritis (CRCRA), Seoul, South Korea, 2Hanyang University Hospital for Rheumatic Diseases, Seoul, South Korea
Presentation Number: 103

Background/Purpose: Several studies of rheumatoid arthritis (RA) incidence and prevalence indicate that occurrence of the disease varies significantly among different populations. However, descriptive studies may be difficult to compare due to methodological differences in terms of case identification and ascertainment. We conducted this study to estimate the nationwide prevalence and incidence of RA with comparison of methodologies and results of other populations, and the prescription trend of disease-modifying anti-rheumatic drug (DMARD) use in South Korea.

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.

Keywords: prescribing trends and rheumatoid arthritis (RA)

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.