Persistence with biologic agents for the treatment of rheumatoid arthritis in Japan

Background: To assess persistence rates of biologic agents for the treatment of rheumatoid arthritis in Japan. Methods: Based on Japanese claims data of 16,214 patients between 2012 and 2014, 6-, 12-, and 18-month persistence rates of different biologic agents were calculated. Determinants of persistence were assessed by means of a multivariate Cox proportional hazard model controlling for age, sex, and comorbidities. A sensitivity analysis was performed with different definitions of persistence and parametric survival analysis. Results: Overall persistence rates in Japan are high and reach 86% after 1 year in the entire sample. The persistence rate for the biologic-naive subpopulation is above 95%. Persistence is higher for older patients (hazard ratio 0.60 [95% confidence interval 0.40-0.91] for >75 years compared to. 60 years) and lower for patients with a high comorbidity score (hazard ratio 1.33; 95% confidence interval 1.03-1.70 for Charlson Comorbidity Index score 3-5 compared to <2). We found a high variation of persistence between different drugs. Conclusion: Japanese rheumatoid arthritis patients have a high persistence rate of biologic treatments. However, multiple factors affect the persistence rate of Japanese patients, including age, comorbidities, and patient type. Naive patients tend to have a higher persistence rate than continuing biologic patients.