QALYs: some challenges.

In the preceding article, Weinstein et al. [1] explain the QALY concept, its methods, and their underlying assumptions. A number of interesting themes for discussion arise from this factual presentation. We restrict ourselves to addressing four issues that we deem particularly challenging. As a general background for our selection of issues, we reiterate a basic point about valuation perspectives: Standard QALYs are meant to express the personal utility of health outcomes as judged ex ante and “on average” by the general public from behind a veil of ignorance about future health (so-called “decision utility”). Standard QALYs thus express value in terms of ex ante self-interest. There are, however, possible alternatives. First, health state utilities may in principle be elicited ex post rather than ex ante, i.e., from people who have or have had direct experience with the health states that are the object of the valuation (so-called “experienced utility”). Second, QALYs may be constructed to express society’s valuation of health outcomes when not only self-interest but also concerns for fairness are taken into account. The choice of approach depends on the question one wishes to answer, and the choice of health state valuation techniques depends on the choice of perspective. The issues we address in the following reflect the above plurality in possible valuation perspectives and are in part independent of each other. One issue is intermethod variation in the estimation of ex ante health state utilities. A second is the existence of unwillingness to trade lifetime in elicitations of experienced utility. A third is the discrepancy between aggregate individual utility of health programs on the one hand and, on the other hand, societal valuations that include concerns for fairness. A fourth is a hitherto much overlooked distinction between healthy individuals’ valuations of states of illness (which is crucial in the conventional QALY procedure) and people’s valuations of treatment (valuations of health gains—including unintended side effects—or avoided health losses), which economic evaluation at the end of the day should be concerned with. Among important issues that we do not address are discounting for time preference and attitudes to uncertainty. For discussions of these, readers are referred to earlier literature, e.g., [2,3]. Because we focus here on challenges to the QALY, we furthermore set aside concerns some hold that health should be valued for its impact on the range of exercisable opportunities open to people rather than on welfarist grounds [4]. Variation in Health State Utilities