Disease activity trajectories in early rheumatoid arthritis following intensive DMARD therapy over 3 years: association with persistence to therapy.

Objective: To identify the disease activity trajectories during intensive triple disease modifying anti-rheumatic drug (DMARD) therapy over 3 years in rheumatoid arthritis (RA) patients and to evaluate the association with treatment persistence. Methods: Disease Activity Score in 28 joints, baseline risk factors and medication usage were obtained from a longitudinal observational cohort of early RA patients, most of whom were treated with combination DMARD therapy consisting of methotrexate, sulfasalazine and hydroxychloroquine. Persistence of each DMARD was defined as the duration of time from initiation to cessation. A group-based trajectory modelling technique was used to identify disease activity trajectories. Result: Three disease activity trajectories (good [43.8%], moderate [39.7%] and poor [16.5%]) were identified in a cohort of 297 patients. Most baseline risk factors, medication usage, the rate of treatment persistence and the effect of persistence on disease activity differed among patients in each of the three trajectories. Although the rate of persistence was higher in the trajectory with a good outcome, the association with persistence was more pronounced among patients who were in the poor outcome trajectory. Persistence with at least two or all three baseline DMARDs was associated with a decrease in disease activity to a broadly similar degree in all trajectories. Conclusion: After correction for other baseline prognostic factors, persistence with initial DMARDs contributes to heterogeneity in disease activity trajectory and there was an association between persistence with initial DMARD therapy and lower long-term disease activity.