Racial Differences in Prevalence and Treatment for Psoriatic Arthritis and Ankylosing Spondylitis by Insurance Coverage in the USA

Introduction Patients with psoriatic arthritis (PsA) and ankylosing spondylitis (AS) may receive suboptimal care, and differences in care by race/ethnicity, sex, and insurance coverage are not well studied. Methods This was a descriptive, retrospective cross-sectional US claims database analysis utilizing the Medicaid multi-state segment of the IBM (R) MarketScan (R) Commercial Claims and Encounters Supplemental Database and Optum Insight Clinformatics (R) Data Mart database for 2019. Patients aged >= 18 years with PsA or AS and continuous medical and pharmacy coverage were included. Outcomes evaluated were prevalence and percentage of patients receiving biologic disease-modifying antirheumatic drugs (bDMARDs)/targeted synthetic DMARDs (tsDMARDs) or visiting a rheumatologist. Outcomes were stratified by race/ethnicity, sex, and insurance coverage, with outcomes determined for commercial insurance, Medicare, and Medicaid enrollees. Differences observed in outcomes were numerical in nature. Results Prevalences of PsA and AS were highest for Medicare enrollees (320 and 156 per 100,000 persons [0.32 and 0.16%], respectively) and lowest for Medicaid enrollees (132 and 71 per 100,000 persons [0.13 and 0.07%], respectively). White patients had the greatest prevalence versus patients of other races/ethnicities. Females had a higher prevalence of PsA than males, while AS prevalence was generally lower for females versus males for each insurance category. The percentage of patients prescribed bDMARDs/tsDMARDs was highest for commercial insurance enrollees (PsA 63%, AS 43%) and lowest for Medicare enrollees (PsA 21%, AS 11%). The proportion of patients who saw a rheumatologist was lower for Medicaid enrollees (PsA 12%, AS 10%) than for commercial insurance or Medicare enrollees (PsA 68%, 55%; AS 67%, 42%). For commercial insurance and Medicare enrollees, the percentage of patients visiting a rheumatologist was similar by race/ethnicity but higher for females versus males. Conclusions The prevalence and treatment of PsA and AS differs by race/ethnicity, insurance coverage, and sex in the USA. Efforts for improving access to care are needed to improve outcomes among all patients.