Background: Psoriatic arthritis (PsA) is a comorbidity commonly associated with psoriasis. Studies have demonstrated delays in the diagnosis and treatment of PsA[1] that may disproportionately affect racial/ethnic minority patients as indicated by one study that found Black Medicaid patients with PsA to be less likely to receive disease-modifying antirheumatic drugs [DMARDs] than White Medicaid patients with PsA [2]. Yet much remains unknown about potential racial/ethnic disparities in PsA management.

Objectives: The objective of our study was to evaluate treatment patterns for PsA by race/ethnicity.

Methods: We performed a cross-sectional study of adult (≥18 years old) patients with PsA who had at least one outpatient visit within the University of Pennsylvania health system between 2010 and 2019. Patients with PsA were identified by the presence of at least two International Classification of Diseases (ICD)-9 or ICD-10 codes for PsA associated with two different healthcare encounters. The primary outcomes were receipt of a prescription for: (i) an oral DMARD, (ii) a biologic DMARD, and (iii) prednisone. Oral DMARDs included apremilast, methotrexate, sulfasalazine, leflunomide, azathioprine, cyclosporine, tofacitinib, hydroxychloroquine, and upadacitnib. Biologic DMARDs included abatacept, adalimumab, brodalumab, certolizumab, etanercept, golimumab, guselkumab, infliximab, ixekixumab, secukinumab, ustekinumab, and risankizumab. The primary independent variable was race/ethnicity categorized as White (reference), Black, Asian, Hispanic, or other race. Multivariable logistic regression was used to assess the relationship between race/ethnicity and each treatment outcome.

Results: The study population included 1781 patients with PsA who were a mean age of 50.7 (SD 14.3), 54.6% female, and 72.5% commercially insured. The racial/ethnic distribution was 81.9% White, 5.6% Black, 4.0% Asian, 3.0% Hispanic, 2.5% other race, and 3.1% missing race/ethnicity. Of these patients, 64.3% were prescribed an oral DMARD, 55.6% were prescribed a biologic, and 44.1% were prescribed prednisone. There were no statistically significant differences across race/ethnicity for prescription of either oral or biologic DMARDs. However, prescription of prednisone did differ by race/ethnicity (p<.005) with Black (54.6%) and Hispanic (56.6%) patients being more likely to receive prednisone prescriptions and Asian (32.4%) patients being less likely to receive prednisone prescriptions than White (44.2%) patients. In adjusted logistic regression models controlling for sociodemographic and other factors, Hispanic patients were more likely to receive a prednisone prescription (OR 1.79, 95% CI 1.01 – 3.20, p=0.05) while Asian (OR 0.58, 95% CI 0.34 – 0.97, p=0.04) patients were less likely to receive a prednisone prescription compared to White patients.

Conclusion: We found Hispanic patients with PsA to be more likely to receive prednisone prescriptions than White patients with PsA but did not identify any racial/ethnic differences in prescription patterns for oral or biologic DMARDs for PsA. Greater use of prednisone among Hispanic patients may reflect different diseases trajectories (e.g., more disease flares or greater disease severity) or other factors that affect prescription patterns that require further study.

REFERENCES:

[1]Favier G, Gladman DD, Merola JF, Armstrong AW, Boehncke WH, Helliwell PS. Benchmarking Care in Psoriatic Arthritis - The QUANTUM Report: A Report from the GRAPPA 2016 Annual Meeting. J Rheumatol . 2017;44(5):674-678.

[2]Ogdie A, Matthias W, Thielen RJ, Chin D, Saffore CD. Racial Differences in Prevalence and Treatment for Psoriatic Arthritis and Ankylosing Spondylitis by Insurance Coverage in the USA. Rheumatol Ther . 2021;8(4):1725-1739.

Disclosure of Interests: Fahad Ahmed: None declared, Alexis Ogdie Consultant of: A. Ogdie has received consulting fees from Amgen, AbbVie, Bristol Myers Squibb, Celgene, CorEvitas (formerly Corrona), Gilead, Janssen, Lilly, Novartis, Pfizer, and UCB., Grant/research support from: A. Ogdie has received grant support from the National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases, Rheumatology Research Foundation, National Psoriasis Foundation, Abbvie (University of Pennsylvania), Pfizer (University of Pennsylvania), Amgen (FORWARD), and Novartis (FORWARD)., Robert Fitzsimmons: None declared, Daniel Shin: None declared, Junko Takeshita Consultant of: JT has served as a consultant for Pfizer Inc. and Janssen Biotech receiving honoraria., Grant/research support from: JT has received a research grant (to the Trustees of the University of Pennsylvania) from Pfizer Inc.