Hospital costs and outcomes among intravenous antifungal therapies for patients with invasive aspergillosis in the United States.

This study determined the economic burden of aspergillosis-related hospitalisations in the United States during years when new antifungal treatments were introduced. A retrospective observational cohort study from the hospital perspective was conducted using national administrative data from the Premier Perspective™ Database. Patients (n=1603) coded for infection caused by Aspergillus species during 1835 admissions who received at least 3 days of intravenous antifungal therapy between 2000 and 2006 were included. All costs were inflated to $US 2006. Length of stay, hospital costs and mortality were compared after stratification by initial antifungal therapy. Median hospital costs were $ 52,803 (25,929-100,730) and did not differ by year over the study period. Intravenous antifungals accounted for 7.2% (range: 0.78-15.9%) of the cost of aspergillosis-related hospitalisation. Crude mortality was 36.7% and was the lowest in the last 2 years of the study (2005, 2006). Although antifungal utilisation changed over the course of the study, initial antifungal choice was not independently associated with crude mortality. In contrast, initial therapy with intravenous voriconazole was associated with reduced total hospitalisation costs and length of hospital stay. Treatment with amphotericin B lipid complex or caspofungin was also independently associated with a reduced length of hospital stay. In this large US study, mortality and costs for aspergillosis-related hospitalisations were considerable, but antifungals accounted for a small percentage of total costs associated with treatment and did not independently affect in-hospital crude mortality. Only initial treatment with intravenous voriconazole was associated with reduced total hospitalisation costs.