Where We Live Matters: Varied Disease Burden and Treatment Patterns in Psoriatic Arthritis in the United States

To evaluate the clinical characteristics, social deprivation, insurance coverage, and medication use across regional subsets of patients with psoriatic arthritis (PsA) in the US.

A cross-sectional study of patients with PsA in the Rheumatology Informatics System for Effectiveness (RISE) registry between January 2020 and March 2023 was conducted. Distribution of high disease activity (HDA; Routine Assessment of Patient Index Data >12), high comorbidity (RxRisk ≥90th percentile), high Area Deprivation Index (ADI ≥80), insurance coverage, prednisone ≥10 mg daily, and all disease-modifying antirheumatic drug (DMARD) therapies across geographic regions were evaluated. Logistic regression models were used to identify regional correlates of HDA and comorbidity.

Of the 32,732 RISE patients with PsA, 58.8% were White women (mean age 57.7 [SD 13.5] years) with private insurance (60%); 55.8% resided in the South. A majority (81.8%) had a body mass index of ≥25, highest in the Midwest (mean 32.4 ± SD 7.8). Women, despite having prevalent HDA, received less biologic DMARD therapy. Both HDA and ADI of ≥80 were more prevalent in the South and Midwest. Compared to the Northeast, Midwest patients had a higher burden of comorbidity (adjusted odds ratio 1.59, 95% confidence interval 0.98 - 2.59) with frequent use of prednisone in conjunction with conventional DMARDs (31.3% vs Northeast 20.5%, South 13.6%, West 17.6%). Uveitis affected 1.2% of the cohort. Only 14 (7.1%) and 20 (10.1%) RISE practices provided care for half of all Medicaid and high-deprivation patients, respectively.

PsA disease characteristics and care vary across the US, with higher-than-expected prednisone use and unequal provider care burden in some regions. Further work is needed to assess the impact of varied regional care on disease outcomes.