Healthcare Utilization and Direct Costs in Patients with Ankylosing Spondylitis Using a Large US Administrative Claims Database

INTRODUCTION: In addition to the considerable patient and societal burdens, the financial burdens of ankylosing spondylitis (AS) are substantial. Understanding both all-cause and AS-specific direct costs in patients with AS is important if we are to understand the financial impact on patients with AS and payers in the United States. This study assessed both all-cause and AS-specific healthcare utilization and direct costs in US patients with AS using administrative claims data. METHODS: Adults aged ≥ 18 years enrolled in the MarketScan(®) Commercial and Medicare databases with ≥ 1 inpatient or ≥ 2 non-rule-out outpatient diagnoses of AS between January 1, 2013, and December 31, 2013, were included. Patients had continuous enrollment with medical and pharmacy benefits for ≥ 12 months before and after the index date (first diagnosis). Non-AS controls were matched up to 5:1 to patients with AS on age, geographic region, index calendar year, and sex. All-cause and AS-specific healthcare utilization and direct costs were measured during the follow-up period and reported as per patient per year. RESULTS: Patients with AS (N = 6679) had significantly higher rates of total all-cause inpatient admission (12% vs 6%), emergency department visits (23% vs 15%), nonhospital-based outpatient visits (100% vs 84%), hospital-based outpatient visits (68% vs 46%), other outpatient services (97% vs 81%), and medication use (97% vs 82%) compared with matched controls (N = 19,951). Patients with AS had approximately tenfold higher median total healthcare costs than matched controls ($24,978 vs $2139 per patient per year), largely driven by increased outpatient and pharmacy costs; P < 0.05 for all comparisons. The median (IQR) total AS-specific healthcare costs were $10,250 ($774, $28,824). CONCLUSION: In this analysis of claims data, increased outpatient and pharmacy costs were key contributors to higher all-cause total healthcare costs in US patients with AS. FUNDING: Novartis Pharmaceuticals Corporation, East Hanover, NJ. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40744-018-0124-4) contains supplementary material, which is available to authorized users.