Excess Costs Associated with Patients with Pulmonary Arterial Hypertension in a US Privately Insured Population

Abstract

Pulmonary arterial hypertension (PAH) is a rare but fatal disease. Little is known about the economic burden associated with PAH patients in the US. The objective of this study was to estimate excess direct costs associated with privately insured PAH patients in the US. From a privately insured claims database (>8 million beneficiaries, 2002-7), 471 patients with PAH were identified using the criteria: two or more claims for primary pulmonary hypertension (PH), International Classification of Diseases, ninth edition, clinical modification (ICD-9-CM) code 416.0; no left heart disease, lung diseases, chronic thromboembolic PH or miscellaneous PH diagnoses within 12 months prior or 1 month after the initial PH claim (index date); one or more claim for right heart catheterization (RHC) within 6 months prior to any PH claim or one or more claim for echocardiogram within 6 months prior to a specialist-diagnosed PH claim; aged 18-64 years. Patients with PAH were matched demographically to controls without PH. Patients were followed as long as continuously eligible; mean follow-up of PAH patients was 24.8 months. Chi-squared tests were used to compare baseline co-morbidities. Wilcoxon rank-sum tests were used to compare direct (medical and pharmaceutical) patient-month costs to insurers. The average age for PAH patients was 52.2 years, and 55.8% were women. Compared with controls, PAH patients had significantly higher baseline rates of co-morbidities (e.g. essential hypertension, diabetes mellitus and congestive heart failure) and a higher mean Charlson Co-morbidity Index score. Mean direct patient-month costs (year 2007 values) were $US2023 for PAH patients and $US498 for controls (p < 0.0001), yielding excess costs of $US1525. Sensitivity analysis restricting the sample to patients diagnosed following RHC yielded a 64% increase in excess costs relative to the original sample. Regarding cost drivers, inpatient services accounted for 45%, outpatient and other services for 38% and prescription drugs for 15% of total direct healthcare costs per patient-month in PAH patients. Circulatory/respiratory system-related patient-month costs were $US724 among PAH patients and $US114 among controls (p < 0.0001). Patients with PAH had substantially higher costs and co-morbidity than controls, with circulatory/respiratory system-related costs accounting for 40% of excess costs. The high burden of illness suggests opportunities for savings from improved management.