Joint Involvement Patterns and Patient-Reported Satisfaction in Difficult-to-Treat Rheumatoid Arthritis: Results from the Multicenter Observational Cohort, FRANK Registry

Objective This study aimed to characterize patterns of joint involvement and clinical features in patients with difficult-to-treat rheumatoid arthritis (D2T RA). Methods A cross-sectional analysis was conducted using the FRANK Registry, a multicenter cohort (n = 3 770). D2T RA was defined based on the 2021 EULAR criteria. Propensity score matching by age and disease duration was applied to compare D2T RA patients with matched non-D2T RA. Joint involvement was assessed using 28-joint counts and Paired Joint Pathology Scores (PJPS). Patient satisfaction was evaluated across four domains: treatment efficacy, cost, activities of daily living (ADL), and global treatment. Results Among 3 770 patients, 108 (2.9%) fulfilled the criteria for D2T RA. Compared with matched controls, D2T RA patients had significantly higher ACPA titers, more frequent use of tsDMARDs, and a higher prevalence of herpes zoster and methotrexate-associated lymphoproliferative disorder (MTX-LPD). Joint-level analysis revealed significantly greater involvement of the acromioclavicular, elbow, wrist, second finger PIP, and knee joints. Patient satisfaction scores were significantly lower in D2T RA, particularly regarding treatment cost and daily functioning. Conclusion D2T RA is associated with distinctive joint involvement, as well as reduced patient satisfaction. A joint-focused and patient-centered management approach is essential to improve outcomes in this challenging RA subset.