Clinical predictors of inadequate response to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) including methotrexate (MTX) in untreated rheumatoid arthritis patients: A single-center observational study.

AbstractObjectives: To investigate predictors of inadequate response to first conventional synthetic disease-modifying antirheumatic drugs(csDMARDs) including methotrexate (MTX) in untreated rheumatoid arthritis (RA) patients in daily clinical practice.Methods: Inadequate response to MTX or other csDMARDs was defined as being not low disease activity at 12 months in more than 3 of 4 composite measures, and discontinuation or start of biologic DMARDs. The association between baseline factors and csDMARDs-IR was assessed by univariate and multivariate logistic regressionanalyses.Results: Four hundred and eleven and 146 patients were started on MTX and other csDMARDs, respectively; 218 patients were responsive to MTX, with a response rate of 47.0%. Tender joint count (TJC, ≥6 in 28joints, odds ratio [OR] = 1.67, 95% confidence interval [CI] 1.06–2.64) and CRP (≥1.0 mg/dL, OR = 1.72, 95%CI: 1.10–2.70) at baseline were identified as predictors on multivariate logistic regressionanalysis. TJC (OR = 3.60, 95%...