Background:Rheumatoid arthritis (RA) predominantly affects women and has a significant impact on childbearing. Several population-based studies identifying incidence, prevalence, and medication use of RA have been reported, yet epidemiological studies focusing on women with RA in childbearing years are missing.Objectives:We aimed to identify the incidence, prevalence and medication use of RA among Korean women in childbearing years.Methods:From National Health Insurance Service (NHIS) data (2009-2016), containing inpatient and outpatient claim information for approximately 97% of the Korean population, we identified 9,217,139 women aged between 20-44 years. Incidence and prevalence of RA in the specific sociodemographic group of women in childbearing age were analyzed, and the prevalence of medication prescription were compared between women with RA and controls without rheumatic diseases such as RA, systemic lupus erythematosus, and ankylosing spondylitis. Individuals with RA were defined by the presence of International Classification of Disease, 10th revision code, M05. The medication use was defined as receiving > 90days prescriptions of NSAIDs, corticosteroids (CSs), and conventional synthetic (cs) disease modifying antirheumatic drugs (DMARDs) or > 1day prescription of biologic (b) DMARDs.Results:Total 24,590 women with RA were identified. The average incidence of RA during 2011-2016 among women in childbearing years was 24.1/100,000 person-years (PYs) (95% CI 20.91-27.31) with a yearly increase from 20.99/100,000 PYs in 2011 to 28.38/100,000 PYs in 2016. The average prevalence of RA during 2009-2016 among women in childbearing years was 105.2/100,000 PYs (95% CI 99.0-111.5) with a minimum of 95.7/100,000 PYs in 2009 and a maximum of 110.5/100,000 PYs in 2016. There were increasing trends in both incidence and prevalence of RA according to age among women in childbearing years peaking in the age group of 40-44 years. The prescriptions of NSAIDs, CSs, csDMARDs and bDMARDs were more frequent in women with RA than controls (NSAIDs; 94.21% vs 21.79%, CSs; 83.65% vs 4.28%, csDMARDs; 91.23% vs 0.41%, bDMARDs; 0.11% vs 0%, p<0.001).Conclusion:The incidence and prevalence of RA are high among Korean women in childbearing years, and medication use was significantly more frequent in this specific population than controls. High disease burden is imposed upon women in childbearing years.References:[1] Won S, Cho SK, Kim D, Han M, Lee J, Jang EJ, Sung YK, Bae SC: Update on the prevalence and incidence of rheumatoid arthritis in Korea and an analysis of medical care and drug utilization. Rheumatol Int 2018, 38(4):649-656.[2] Smeele HTW, Dolhain R: Current perspectives on fertility, pregnancy and childbirth in patients with Rheumatoid Arthritis. Seminars in arthritis and rheumatism 2019, 49(3s):S32-s35.Table 1.Medication use among women with RA and controls in childbearing age between 20-44 years during 2009-2016Control(n=155,486)RA(n=23,756)n(%)n(%)PNSAIDs33,887(21.79)22,380(94.21)<.0001Steroids6,653(4.28)19,871(83.65)<.0001csDMARDs634(0.41)21,673(91.23)<.0001bDMARDs0(0.00)27(0.11)<.0001RA, rheumatoid arthritis; NSAID, non-steroidal anti-inflammatory drug; cs, conventional synthetic; b, biologic; DMARDs, disease modifying antirheumatic drugsDisclosure of Interests:None declared
Interleukin-6 receptor inhibition with tocilizumab reduces disease activity in rheumatoid arthritis with inadequate response to disease-modifying antirheumatic drugs: The tocilizumab in combination with traditional disease-modifying antirheumatic drug therapy study