Factors associated with increased hospital costs in patients treated with lipid-based amphotericin B for empirical therapy

Lipid-based amphotericin B agents have been studied in a number of clinical settings and patient populations, most notably as empirical therapy for patients at-risk for systemic fungal infection and for patients with documented invasive disease. In clinical practice, lipid-based therapies have been considered second- or even third-line therapy due to concerns about costs. However, few analyses have been conducted to determine those factors associated with empirical antifungal therapy and lipid-based agents that are most likely to influence hospital costs and length of stay. The purpose of this analysis is to determine which demographic, treatment, and clinical outcome factors contribute to increased hospital costs and length of stay in patients treated empirically with a lipid-based amphotericin B agent. A retrospective analysis of 89 patients enrolled in the clinical study was performed to assess hospital costs and length of stay following the start of empirical antifungal therapy. Bivariate and multivariate regressions were performed to identify variables most likely to affect hospital costs and length of stay. Allogeneic bone marrow transplant (BMT) status, days of treatment, doubling of baseline creatinine, and dialysis were found to be predictive both of increased hospital costs and length of stay. Length of stay and number of concomitant nephrotic agents also were found to affect hospital costs. Overall, risk factors and clinical outcomes associated with nephrotoxicity increased hospital costs and length of stay in patients treated empirically with lipid-based antifungal agents. Renal dialysis also increased hospital cost significantly. For empirical antifungal therapy, providers should consider both patient-specific risk factors and product-specific outcomes in selecting an appropriate agent.