Abstract
This study utilized model-based meta-analysis (MBMA) to systematically assess the efficacy of methotrexate (MTX) monotherapy in improving rheumatoid arthritis (RA) symptoms and function. The assessment was based on indicators such as Disease Activity Score 28 (DAS28), Health Assessment Questionnaire, and American College of Rheumatology (ACR) criteria. Additionally, the study investigated the impact of dosage, disease duration, and serum markers-C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)-on treatment efficacy. A systematic review of randomized controlled trials yielded data from 69 studies involving 7999 patients. Efficacy models for DAS28, ACR20, and ACR50 were developed to explore the impact of time and dosage, with simulations conducted to predict outcomes at 12 weeks. Results showed that the maximum reduction in DAS28 (Emax) was -54.90% (RSE: 13%), with an ET50 of 20.6 weeks (RSE: 26%). For ACR20 and ACR50, Emax values were 70.3% (RSE: 3%) and 49.4% (RSE: 24%), with ET50s of 6.69 (RSE: 7%) and 27.3 (RSE: 37%) weeks, respectively. Neither dosage nor patient-specific factors like disease duration, CRP, or ESR significantly influenced efficacy. MTX is effective in the early treatment of RA but often fails to achieve remission in patients.