Baseline factors predicting change from the initial DMARD treatment during the first 2 years of rheumatoid arthritis: experience in the ERAN inception cohort

BACKGROUND Outcomes in early Rheumatoid Arthritis (RA) may be improved by rapidly establishing a stable and effective disease modifying anti-rheumatic drug (DMARD) treatment regimen. We aimed to investigate whether baseline factors and initial treatment strategies are associated with changes to the first DMARD treatment, due to either Lack of Efficacy (LoE) or Adverse Drug Reaction (ADR) within 2 years of presentation. METHODS Reasons for changes from initial DMARD therapy within 2 years of baseline, and associated factors, were examined using logistic regression in data from the Early RA Network (ERAN) inception cohort. RESULTS Data were available for 766 participants. 410 (54%) changed their initial DMARD regime within 2 years, including 230 (56%) due to Lack of Efficacy (LoE) and 139 (34%) due to Adverse Drug Reaction (ADR). The first DMARD was recorded as methotrexate monotherapy in 336 (44%), sulphasalazine monotherapy in 273 (36%), or combined methotrexate/sulphasalazine/hydroxychlorquine in 52 (7%).Baseline predictors of changing DMARD (for all reasons) were HAQ-disability (aOR 1.44, 95% CI 1.12 - 1.86), poor mental health (aOR 1.44, 95% CI 1.16 - 1.78) and extra-articular disease (aOR 1.78, 95% CI 1.00 - 3.16). In this model, the triple combination therapy also predicted lower likelihood of DMARD change (aOR 0.30, 95% CI 0.12 - 0.79).Subgroup analyses showed that MTX monotherapy was associated with lower risk of change due to ADR. Combination therapy conferred lower risk of change due to LoE. Poor mental health was associated with change due to ADR, and extra-articular disease, HAQ-disability at baseline, and younger age predicted LoE. CONCLUSIONS Our findings suggest that non-pharmacological interventions to improve disability and mental health, may reduce initial DMARD treatment failure.