A decision model was used to synthesise the evidence from published studies, epidemiological data, and one key clinical trial (Cornely, et al. 2007, see ‘Other Publications of Related Interest’ below for bibliographic details). The time horizon was 100 days from the start of posaconazole treatment. The authors stated that they took a Canadian health system perspective.
The key clinical outcomes were the rates of developing invasive fungal infections while on posaconazole, treatment discontinuation due to adverse events, and deaths. Literature reviews were undertaken to search for relevant evidence in PubMed and on the Internet, using Google Scholar. Randomised controlled trials from 2000 to 2010 were selected. The key trial (Cornely, et al. 2007) was a randomised head-to-head comparison of posaconazole versus fluconazole or itraconazole, in 602 patients.
Monetary benefit and utility valuations:
Measure of benefit:
The measure of benefit used was life-years saved.
The direct medical costs included pharmaceuticals, baseline electrocardiogram for posaconazole and systemic therapy for invasive fungal infections. Costs were valued using hospital prices, and Canadian and International economic literature. Fungal infection costs were weighted by the incidence of invasive aspergillus and candidiasis. The costs were presented in Canadian dollars (CAD), where CAD 1 was equal to one US $. Where necessary, they were adjusted to 2010 prices using the consumer price index for health care.
Analysis of uncertainty:
One-way analyses were performed, using 95% confidence intervals, for three parameters; drug discontinuations, the incidence of invasive fungal infections, and the costs of treating infections. Treatment duration was varied and tested according to results from the key clinical trial. The sensitivity analysis results were reported in a table.