[Quality adjustment of life years--possibilities, limitations, alternatives]

QALYs express the sum of individual utility gains from medical interventions. As such they are potentially a useful measure in deciding how to allocate resources. They should not, however, be equated with the overall value that society places on different health care programmes. The latter is determined not only by the number of QALYs gained, but also by a series of distributional and ethical considerations. This should be made clear in the presentation of QALY-calculations, particularly in cost-per-QALY league tables. More comprehensive measures of social value that may be used in cost-utility studies need investigating.