Predictive Factors of Methotrexate Monotherapy Success in Patients with Rheumatoid Arthritis in a National Referral Center: A Cohort Study

Background Methotrexate (MTX) remains the recommended first-line treatment for rheumatoid arthritis (RA); however, its response varies and is influenced by various factors. This study aimed to identify predictors of MTX monotherapy treatment success in an Indonesian cohort. Methods This retrospective cohort study included newly diagnosed RA patients receiving MTX monotherapy. Treatment success was defined as achieving remission or low disease activity according to Disease Activity Score-28 with erythrocyte sedimentation rate (DAS28-ESR) after 12 months of MTX therapy. The association between demographic, clinical, and laboratory factors and achieving therapy targets was evaluated using multivariate logistic regression analysis. Results Among 254 subjects, 59.4% achieved treatment success with MTX monotherapy, with remission attained in 33% and low disease activity in 26.4%. Most subjects were female (95.7%) with a mean age of 48 ± 11 years. Multivariate analysis revealed that lower disease activity (OR 1.97; 95% CI [1.04–3.72]), normal ESR (OR 2.58; 95% CI [1.05–6.34]), normoweight (OR 2.55, 95% CI [1.45–4.49]), and tender joint count ≤ 5 (OR 2.45, 95% CI [1.31–4.58]) were significant predictors of treatment success. Conclusion The rate of MTX monotherapy success in our study was 59.4%. Lower disease activity, normal ESR, normoweight, and fewer tender joints at baseline were significant predictors of treatment success.