Comparing treatment outcomes using utility assessment for health-related quality of life.

When comparing treatments, the simple question of which treatment produces a better outcome prompts a complicated answer if both quantity and quality of life are considered. This is particularly evident when the treatment associated with better survival worsens quality of life, at least for part of the time, or when certain aspects of quality of life are better with one treatment while other aspects are better with another treatment. Utility assessment is an evolving discipline that offers an attractive conceptual solution to these problems. The popular approaches are described, and one particular method, the standard gamble, is advocated. Utility is easily measured by the standard gamble, and it has good psychometric and theoretical properties.