Incidence and prevalence of systemic lupus erythematosus among Korean women in childbearing years: A nationwide population-based study

Background Most women with systemic lupus erythematosus (SLE) are diagnosed with the disease in their reproductive years, but the incidence and prevalence of SLE among women of childbearing age have not been studied. The objective of this study was to estimate the incidence and prevalence of SLE among the Korean women of childbearing age. Methods Women aged 20 to 44 years with SLE were identified from National Health Insurance Service - National Health Information Database (2009-2016), which contain health information of approximately 97% of the Korean population. SLE was defined by International Classification of Diseases, 10th revision code, M32. Incidence and prevalence were calculated per 100,000 person-years and stratified by year and age. Results A total of 12,756 women with SLE were identified. The incidence of SLE from 2011 to 2016 among women in childbearing years was 8.18/100,000 person-years (95% CI 7.94-8.43), with the highest incidence in 2016 (8.56/100,000 person-years, 95% CI 7.95-9.17) and the lowest incidence in 2012 (7.85/100,000 person-years, 95% CI 7.28-8.42). The prevalence of SLE from 2009 to 2016 among women in childbearing years was 77.07/100,000 person-years (95% CI 75.76-78.39), with the highest prevalence in 2014 (79.47/100,000 person-years, 95% CI 77.64-81.30) and the lowest in 2010 (74.19/100,000 person-years, 95% CI 72.45-75.93). The peak age for SLE incidence was between 25-39 years, and lower incidence was seen in the early (20-24 years) and late (40-44 years) childbearing age periods. There was an increasing trend in prevalence according to age in women of childbearing age, with the highest prevalence occurring in the 40-44 age group. Conclusions The risk and burden of SLE are high among women during their childbearing years. This calls for special attention to this particular population group when allocating health resources.