Healthcare Resource Use and Direct Costs in Patients with Ankylosing Spondylitis and Psoriatic Arthritis in a Large US Cohort.

OBJECTIVE

Direct costs of ankylosing spondylitis (AS) and psoriatic arthritis (PsA) have not been well characterized in the United States. This study assessed healthcare resource use and direct cost of AS and PsA, and identified predictors of all-cause medical and pharmacy costs.

METHODS

Adults aged ≥ 18 with a diagnosis of AS and PsA were identified in the MarketScan databases between October 1, 2011, and September 30, 2012. Patients were continuously enrolled with medical and pharmacy benefits for 12 months before and after the index date (first diagnosis). Baseline demographics and comorbidities were identified. Direct costs included hospitalizations, emergency room and office visits, and pharmacy costs. Multivariable regression was used to determine whether baseline covariates were associated with direct costs.

RESULTS

Patients with AS were younger and mostly men compared with patients with PsA. Hypertension and hyperlipidemia were the most common comorbidities in both cohorts. A higher percentage of patients with PsA used biologics and nonbiologic disease-modifying drugs (61.1% and 52.4%, respectively) compared with patients with AS (52.5% and 21.8%, respectively). Office visits were the most commonly used resource by patients with AS and PsA (∼11 visits). Annual direct medical costs [all US dollars, mean (SD)] for patients with AS and PsA were $6514 ($32,982) and $5108 ($22,258), respectively. Prescription drug costs were higher for patients with PsA [$14,174 ($15,821)] compared with patients with AS [$11,214 ($14,249)]. Multivariable regression analysis showed higher all-cause direct costs were associated with biologic use, age, and increased comorbidities in patients with AS or PsA (all p < 0.05).

CONCLUSION

Biologic use, age, and comorbidities were major determinants of all-cause direct costs in patients with AS and PsA.