Disease-modifying antirheumatic drugs (DMARDs) are the standard of care for rheumatoid arthritis (RA); however, studies have found that many patients do not receive them. We examined predictors of starting and stopping DMARDs among a longitudinal cohort of patients with RA.
Study participants came from a cohort of RA patients recruited from a random sample of rheumatologists' practices in Northern California. We examined patterns and predictors of stopping and starting nonbiologic and biologic DMARDs during 1982-2009 based on annual questionnaires. Stopping was defined as stopping all DMARDs and starting was defined as transitioning from no DMARDs to any DMARDs across 2 consecutive years.
The analysis of starting DMARDs included 471 subjects with 1,974 pairs of years with no DMARD use in the first of 2 consecutive years. From this population, subjects started DMARD use by year 2 in 313 (15.9%) of the pairs. The analysis of stopping DMARDs included 1,026 subjects with 7,595 pairs of years with DMARD use in the first of 2 consecutive years; in 423 pairs (5.6%), subjects stopped DMARD use by year 2. In models that adjusted for RA-related factors, sociodemographics, and comorbidities, significant predictors of starting DMARDs included younger age, Hispanic ethnicity, shorter disease duration, and the use of oral glucocorticoids. In separate adjusted models, predictors of stopping DMARDs included Hispanic ethnicity and low income, while younger age was associated with a reduced risk of stopping.
Efforts to improve DMARD use should focus on patient age, ethnicity, and income and RA-related factors.