We read with great interest the recent original article by Jung et al., entitled “Difficult-to-treat rheumatoid arthritis among elderly patients from the KOBIO registry,” published in the European Journal of Internal Medicine [1]. As the global population ages, this study leverages comprehensive real-world data from the KOBIO registry to focus on the vulnerable population aged 65 and older, identifying that younger elderly age (adjusted OR=0.905, P = 0.012), high Routine Assessment of Patient Index Data 3 (RAPID3) scores (adjusted OR=1.082, P = 0.044), and no previous use of leflunomide (adjusted OR=0.446, P = 0.009) are independent risk factors for difficult-to-treat rheumatoid arthritis (D2T-RA).
