Changes in healthcare utilization and costs associated with sildenafil therapy for pulmonary arterial hypertension: a retrospective cohort study.

Background: Little is known concerning the degree to which initiation of sildenafil for pulmonary arterial hypertension (PAH) impacts patterns of healthcare utilization and costs.

Methods: Using a large US health insurance claims database, we identified all patients with evidence of PAH (ICD-9-CM diagnosis codes 416.0, 416.8) who received sildenafil between 1/1/2005 and 9/30/2008. Date of the first-noted prescription for sildenafil was designated the "index date," and claims data were compiled for all study subjects for 6 months prior to their index date ("pretreatment") and 6 months thereafter ("follow-up"); patients with incomplete data during either of these periods were excluded. Healthcare utilization and costs were then compared between pretreatment and follow-up for all study subjects.

Results: A total of 567 PAH patients were identified who began therapy with sildenafil and met all other study entry criteria. Mean (SD) age was 52 (10) years; 73% were women. Healthcare utilization was largely unchanged between pretreatment and follow-up, the only exceptions being decreases in the mean number of emergency department visits (from 0.7 to 0.5 per patient; p<0.01) and the percentage of patients hospitalized (from 35% to 29%; p=0.01). The mean cost of all PAH-related medication was $7139 during pretreatment and $14,095 during follow-up (sildenafil cost during follow-up= $5236); exclusive of PAH-related medications, however, total healthcare costs decreased modestly (from $30,104 to $27,605) (p<0.01 for all comparisons).

Conclusions: The cost of sildenafil therapy may be partially offset by reductions in other healthcare costs.