Initiation of Disease-Modifying Antirheumatic Drugs in Older Medicare Beneficiaries With New Diagnosis of Late-Onset Rheumatoid Arthritis

Objective: Older adults with rheumatoid arthritis (RA) account for up to one-third of the RA population and are less likely to receive optimal treatment. For the subgroup of older adults with late-onset RA (LORA), who experience more symptomatic and progressive disease, suboptimal treatment could be more consequential than the general population who age with RA. We evaluated use of disease-modifying antirheumatic drugs (DMARDs) in older adults with a new diagnosis of LORA. Methods: In this retrospective observational study, we identified adults 66 years of age or older with a new diagnosis of LORA using Medicare data from 2008 to 2017. Information on baseline patient characteristics and DMARD initiation during the first 12 months after LORA diagnosis were collected. We also assessed concomitant use of glucocorticoids (GCs). Results: We identified 33,373 older adults with new diagnosis of LORA. Average age at LORA diagnosis was 76.7 (SD 7.6); 75.4% were female, 76.9% were White, and 35.6% had low-income subsidy (LIS). Less than one-third were initiated on a DMARD (28.9%). In multivariable analyses, DMARD initiation was associated with younger age, fewer comorbidities, and absence of LIS status. Concomitant long-term (>3 months) GC use was higher among those on any DMARD (44.3%) compared with those without (15.2%). Conclusions: DMARD initiation after new diagnosis of LORA is low despite current clinical practice guidelines recommending early aggressive initiation of treatment. Long-term GC use is common among those on any DMARDs, raising concern for suboptimal DMARD use. Further studies are needed to understand drivers of DMARD use in older adults.