Factors associated with the initiation of disease-modifying antirheumatic drugs in newly diagnosed rheumatoid arthritis: a retrospective claims database study.

OBJECTIVES

The objectives of this study were to quantify the proportion of US patients with newly diagnosed rheumatoid arthritis (RA) in whom disease-modifying antirheumatic drug (DMARD) therapy was initiated within 12 months following diagnosis, to determine mean time to initiation, to compare the characteristics of initiators versus noninitiators, and to identify factors associated with noninitiation.

METHODS

A retrospective study was conducted using claims from the databases of commercial managed care and Medicare supplemental managed care to identify patients with claims containing codes for RA dated January 1, 2004, through September 30, 2008. The percentage of patients with RA and a prescription for a DMARD within 12 months after the index date (initiators) was evaluated. The characteristics of DMARD initiators and noninitiators during the preindex period were compared, including demographic and clinical characteristics, health care resource utilization, and cost variables. The probability of DMARD initiation was determined using survival analysis. Multivariate analysis was performed to estimate mean time from diagnosis to DMARD initiation based on demographic and clinical variables.

RESULTS

Of 26,911 patients with newly diagnosed RA identified in the database searches, 63% had been prescribed a DMARD within 12 months after diagnosis. DMARD initiators were significantly more likely to have had a rheumatologist visit and rheumatoid factor testing and were more likely to have received a corticosteroid and/or an NSAID (all, P < 0.001). DMARD initiators had significantly lower total costs ($10,534 vs $12,725, respectively) and pharmacy drug costs ($2438 vs $2822) over the preindex period compared with noninitiators (both, P < 0.001). Independent factors associated with a greater likelihood of DMARD initiation included a rheumatologist visit, rheumatoid factor testing, NSAID use, and corticosteroid use. Age ≥85 years and the presence of comorbidities were associated with a significantly lower likelihood of DMARD initiation.

CONCLUSIONS

Among managed care enrollees in the present analysis, 37% of patients newly diagnosed with RA were not being treated with DMARDs in the first 12 months after diagnosis. Time to DMARD initiation plateaued after 90 days, suggesting that if a patient was not prescribed a DMARD soon after RA diagnosis, he or she was not likely to receive one.