Inquiry into the relationship between equity weights and the value of the QALY.

BACKGROUND: A commonly held view of the decision rule in economic evaluations in health care is that the final incremental cost-effectiveness ratio needs to be judged against some threshold, which is equal for all quality-adjusted life-year (QALY) gains. This reflects the assumption that "a QALY is a QALY" no matter who receives it, or the equity notion that all QALY gains are equally valuable, regardless of the context in which they are realized. If such an assumption does not adequately reflect the distributional concerns in society, however, different thresholds could be used for different QALY gains, whose relative values can be seen as "equity weights." AIM: Our aim was to explore the relationship between equity or distributional concerns and the social value of QALYs within the health economics literature. In light of the empirical interest in equity-related concerns as well as the nature and height of the incremental cost-effectiveness ratio threshold, this study investigates the "common ground" between the two streams of literature and considers how the empirical literature estimating the incremental cost-effectiveness ratio threshold treats existing distributional considerations.