Introduction: Benefits of disease-modifying anti-rheumatic drugs (DMARD) in early rheumatoid arthritis patients (ERAP) will be achieved if patients follow prescribed treatment. Objective was to investigate whether timing of first non-persistence period and/or duration of persistence during the first 4 years of follow-up predicted disease outcomes at the 5(th) year in a cohort of ERAP, initiated in 2004.
Patients and methods: Up to February 2015, charts of 107 ERAP with at least 5 years of follow-up and prospective 6-month assessments of disease activity, disability and persistence were reviewed. Non-persistence was defined as omission of DMARD and/or corticosteroids for at least 7 consecutive days; regarding methotrexate, one weekly missing dose was considered non-persistence. Persistence was recorded through an interview (up to 2008) and thereafter through a questionnaire; persistence duration was recorded in months of continuous medicationtaking. At the 5(th) year, disease activity was defined according to Disease Activity Score (DAS)28, and disability according to Health Assessment Questionnaire (HAQ). Descriptive statistics and linear and Cox regression analyses were used.
Results: At study entry, patients were more frequently middle-aged (39.1 ± 13.3 years) and female (88.8%), as well as more likely to have high disease activity and disability. Over the first 4 years of follow-up, 54.2% of the patients had indications for oral corticosteroids and all traditional DMARDs. Almost 70% had at least one period of non-persistence, and their follow-up (median, 25th-75th interquartile range) to first non-persistence period was 13 months (1-31). Persistence duration during the first 4 years predicted subsequent DAS28 (in addition to gender and baseline DAS28) and HAQ (in addition to age). During the 5(th) year, 68 patients (56 women) achieved sustained remission (DAS28 < 2.6). In female population (n = 95), baseline DAS28 (odds ratio [OR], 0.65; 95 % confidence interval [CI], 0.50-0.83; p = 0.001) and persistence duration (OR, 1.04; 95 % CI, 1-1.08; p = 0.05) were predictors. Also, 84 patients achieved sustained function (HAQ <0.21), and baseline DAS28 and age were the only predictors. Timing of first non-persistence period did not impact outcomes.
Conclusions: Persistence duration with DMARDs within the first 4 years of RA predicted subsequent favorable outcomes in ERAP; additional predictors were younger age, male gender and lower disease activity at diagnosis.