Taking quality of life into account in health economic analyses.

Cost-utility analysis is the most commonly used approach to incorporating quality-of-life considerations into economic analyses in health care. This type of analysis produces a ratio of the incremental cost of one intervention over another to the incremental benefit produced, measured in quality-adjusted life years. To be suitable for use in calculating quality-adjusted survival, quality of life must be measured in the form of a utility. Direct utility assessment techniques are grounded in decision analytic theory and are conceptually complex and impractical for use in the clinical trial setting. Alternatives include global rating scale items with appropriate "transformations" and health state classification indices. The first cancer trials to collect economic data and utilities from patients using these techniques are now under way. These trials will serve to answer not only biological questions, but also health policy questions about whether the additional cost of the more expensive therapy is justified by the benefit it produces in both length and quality of life.