THU0240 The Comparative Effectiveness of Oral Methotrexate Versus Subcutaneous Methotrexate for the Initial Treatment of Early Rheumatoid Arthritis

Background Methotrexate (MTX) is considered the preferred initial DMARD for the treatment of rheumatoid arthritis, but the preferred route of administration (oral or subcutaneous) is unclear. Objectives To determine the comparative effectiveness of initial therapy with subcutaneous (sc) versus oral methotrexate (MTX) for patients with early rheumatoid arthritis (ERA) in routine clinical care. Methods Patients with early inflammatory arthritis initiating methotrexate therapy were included from the Canadian Early Arthritis Cohort (CATCH), a multicenter, prospective cohort study of patients with ERA. All patients had a diagnosis of RA by 2010 criteria, symptom duration < 1 year and were MTX-naive or minimally exposed to MTX. The exposure was initial route of MTX (oral vs. sc) and the outcome was DAS-28 over the first year (3, 6, 9, 12 months). A linear generalized estimating equation (GEE) model was used to account for repeated measures within patients while adjusting for potential confounders. Results 653 patients were included (442 oral MTX, 211 sc MTX). Patients treated with sc MTX were more likely to have erosions at baseline (35% vs. 25%, p=0.01), were less likely to receive other DMARDs (38% vs. 58%, p