Disability-adjusted life years: a critical review.

The disability-adjusted life year (DALY) has emerged in the international health policy lexicon as a new measure of the 'burden of disease'. We argue that the conceptual and technical basis for DALYs is flawed, and its assumptions and value judgements are open to serious question. In particular, the implications of age-weighting and discounting are found to be unacceptable. Moreover, the proponents of DALYs do not distinguish between the exercises of measuring the burden of disease and of allocating resources. But the appropriate information sets for the two exercises are quite different. Allocating resources by aggregate DALY-minimization is shown to be inequitable.