Health Care Effect of Disease-Modifying Antirheumatic Drug Use on Patients with Rheumatoid Arthritis.

BACKGROUND

Disease-modifying antirheumatic drugs (DMARDs) are recommended as the standard of care for patients with rheumatoid arthritis (RA) due to their ability to reduce pain and disability; however, DMARD use is low in some subgroups of the RA population.

OBJECTIVE

To identify characteristics associated with DMARD use in the overall cohort of patients with RA and newly diagnosed RA patients.

METHODS

This retrospective observational study used claims from a large national health plan. Use of DMARDs was measured according to the Healthcare Effectiveness Data and Information Set (HEDIS) as the proportion of patients with RA receiving DMARDs. Following HEDIS measure technical specifications, we identified patients aged 18-89 years with continuous enrollment during 2014 (measurement year) with ≥ 2 claims for RA outpatient visits and/or discharges on different dates between January and November 2014. Additionally, we identified a subset of patients newly diagnosed with RA in 2014 based on absence of any claims for RA or DMARDs in 2013. Descriptive analyses and bivariate associations were used to compare demographic and clinical characteristics of patients with RA with or without DMARD use in 2014. Health care resource utilization (HCRU) and costs were compared in 2014 for patients enrolled in Medicare Advantage Prescription Drug (MAPD) plans during both 2014 and 2015. Regression models were used to evaluate patient and provider characteristics associated with DMARD use in 2014 and the effect on HCRU and costs.

RESULTS

Among the 33,880 patients identified with RA in 2014, most patients received a DMARD (75.2%); 29.4% of patients newly diagnosed with RA had been treated with DMARDs in 2014. Patients with DMARD use, on average, were younger (aged 67 years ± 10.7 vs. 69 years ± 10.7) and healthier (Deyo-Charlson Comorbidity Index [DCCI] 2.4 ± 1.9 vs. 2.6 ± 2.1) and included a greater proportion of women (75.9% vs. 71.0%) than those with no DMARD use ( < 0.0001). Use of DMARDs ( < 0.0001) was associated with 14.5% fewer hospitalizations and 18.0% fewer emergency department visits. Although total costs increased by 15.0% with use of DMARDs, when the cost of DMARDs was excluded, the total cost decreased by 13.7% ( < 0.0001). Female gender (32.2%), higher claims-based index for RA severity score (47.0%), higher RxRisk-V score (26.7%), visit to a rheumatologist (34.3%), and use of glucocorticoids (17.7%) increased the odds of DMARD use ( < 0.0001). Use of certain classes of medication, such as nonsteroidal anti-inflammatory drugs (12.3%), opioids (19.5%), antidepressants (20.0%), muscle relaxants (12.5%), and anticonvulsants (15.5%), were associated with lower use of DMARDs ( < 0.0001).

CONCLUSIONS

We found significant differences in demographic and clinical characteristics between patients with and without DMARD use, which can potentially inform treatment decisions regarding DMARD use as deemed necessary by the provider. Future research should investigate the reasons for lack of treatment.

DISCLOSURES

This study was supported by funding from Eli Lilly to Humana as a collaborative research project involving employees of both companies. Boytsov, Saverno, Zhang, and Gaich are employees of Eli Lilly. Nair, Bhattacharya, Abbott, and Dixon are employees of Humana, which received funding from Eli Lilly to complete this research.