Quality-adjusted life years: origins, measurements, applications, objections.

Quality-adjusted life years or QALYs are used to combine, in a single measure, information about the quantity and quality of life produced by a health intervention. They have been used as outcome measures in clinical trials and in cost-effectiveness analyses. This paper describes how QALYs are assessed and how they are used. Methodological and theoretical problems are discussed as are ethical objections to the utilitarian ethos underlying their use. It is concluded that QALYs are part of a technology that is still in development but, because of the lack of alternatives, they will certainly continue to be used. It is important to resolve the outstanding methodological issues and reach an ethical consensus to ensure that QALYs truly reflect community goals.