Economic evaluation of voriconazole for the treatment of candidemia in Canadian adults.

BACKGROUND: Candidemia is a common cause of nosocomial bloodstream infection. When selecting therapeutic treatments for candidemia, cost-effectiveness is an important consideration. The present study assessed the cost-effectiveness of voriconazole for the treatment of candidemia.
METHODS: A decision-analytical model was used for evaluating the cost-effectiveness of voriconazole compared with a regimen of conventional amphotericin B (CAB) followed by fluconazole (FLU) in the treatment of non-neutropenic patients diagnosed with candidemia in the Canadian setting, based on the Global Candidemia Study. The time frame of the model was 98 days (14 weeks). Model parameters were based primarily on clinical outcome, and resource use data collected from the clinical trial were used. Supplemental data were obtained from an independent panel of 12 Canadian experts for parameters not available from the clinical trial. Unit costs were collected from Canadian sources. The outcome variables selected in the study were the number of patients cured within 98 days, the number of patients surviving at 98 days and the number of patients avoiding toxicity. Incremental costs per outcome were calculated to compare the cost-effectiveness analyses (both probabilistic and one-way sensitivity analyses were performed).
RESULTS: The cost-effectiveness analysis demonstrated a difference of $1,121 in the total average cost of treatment with voriconazole ($70,489) versus CAB/FLU ($69,368). While the costs of voriconazole exceeded the costs of CAB/FLU, these costs were almost completely offset by lower hospitalization costs. While patients in both treatment arms experienced cure rates of 41%, both the percentage of patients surviving at day 98 (64.5% versus 58.2%) and the percentage of patients avoiding toxicity (64.5% versus 52.5%) were higher in the voriconazole arm. Accounting for differences in total costs and clinical outcomes, this analysis estimated an incremental cost per patient surviving at day 98 of $17,739, and an incremental cost per patient avoiding toxicity of $9,298. In the case of cost per patient cured, voriconazole had a higher cost ($1,121) than CAB/FLU. The results of the deterministic and probabilistic sensitivity analyses indicated that the model was robust.
CONCLUSIONS: Results of the decision-analytical model provided evidence to support the cost-effectiveness of voriconazole relative to a regimen of CAB/FLU in the treatment of non-neutropenic patients diagnosed with candidemia in the Canadian setting.