Systematic overview of cost-utility assessments in oncology.
PURPOSE: Cost-utility analyses (CUAs) present the value of an intervention as the ratio of its incremental cost divided by its incremental survival benefit, with survival weighted by utilities to produce quality-adjusted life years (QALYs). We critically reviewed the CUA literature and its role in informing clinical oncology practice, research priorities, and policy. METHODS: The English-language literature was searched between 1975 and1997 for CUAs. Two readers abstracted from each article descriptions of the clinical situation and patients, the methods used, study perspective, the measures of effectiveness, costs included, discounting, and whether sensitivity analyses were performed. The readers then made subjective quality assessments. We also extracted utility values from the reviewed papers, along with information on how and from whom utilities were measured. RESULTS: Our search yielded 40 studies, which described 263 health states and presented 89 cost-utility ratios. Both the number and quality of studies increased over time. However, many studies are at variance with current standards. Only 20% of studies took a societal perspective, more than a third failed to discount both the costs and QALYs, and utilities were often simply estimates from the investigators or other physicians. CONCLUSION: The cost-utility literature in oncology is not large but is rapidly expanding. There remains much room for improvement in the methodological rigor with which utilities are measured. Considering quality-of-life effects by incorporating utilities into economic studies is particularly important in oncology, where many therapies obtain modest improvements in response or survival at the expense of nontrivial toxicity.