Associations of Cost Sharing With Rheumatoid Arthritis Disease Burden

ObjectiveTo evaluate the regional variation of cost sharing and associations with rheumatoid arthritis (RA) disease burden in the US. MethodsPatients with RA from rheumatology practices in Northeast, South, and West US regions were evaluated. Sociodemographics, RA disease status, and comorbidities were collected, and Rheumatic Disease Comorbidity Index (RDCI) score was calculated. Primary insurance types and copay for office visits (OVs) and medications were documented. Univariable pairwise differences between regions were conducted, and multivariable regression models were estimated to evaluate associations of RDCI with insurance, geographical region, and race. ResultsIn a cohort of 402 predominantly female, White patients with RA, most received government versus private sponsored primary insurance (40% vs. 27.9%). Disease activity and RDCI were highest for patients in the South region, where copays for OVs were more frequently more than $25. Copays for OVs and medications were less than $10 in 45% and 31.8% of observations, respectively, and more prevalent in the Northeast and West patient subsets than in the South subset. Overall, RDCI score was significantly higher for OV copays less than $10 as well as for medication copays less than $25, both independent of region or race. Additionally, RDCI was significantly lower for privately insured than Medicare individuals (RDCI -0.78, 95% CI [-0.41 to -1.15], P < 0.001) and Medicaid (RDCI -0.83, 95% CI [-0.13 to -1.54], P = 0.020), independent of region and race. ConclusionCost sharing may not facilitate optimum care for patients with RA, especially in the Southern regions. More support may be required of government insurance plans to accommodate patients with RA with a high disease burden.