Quality-adjusted Life Years, Utility Theory, and Healthy-years Equivalents

TLDR

Decisions about medical treatments involve value trade‑offs between quality and quantity of life, and the most common outcome measure is the quality‑adjusted life year (QALY). The study proposes the healthy‑years equivalent (HYE) as an alternative outcome measure. HYE is derived directly from the individual's utility function and can be measured in various ways. The authors show that QALYs only partially reflect individual preferences, potentially leading to suboptimal choices, whereas HYE fully captures preferences and integrates morbidity and mortality, enabling cross‑program comparisons.

Abstract

Decisions about medical treatments and the settings of health programs are not purely technical, but also involve issues of value such as the evaluation of trade-offs between quality of life (morbidity) and quantity of life (mortality). The most commonly used measure of outcome in such cases is the quality-adjusted life year (QALY). The authors show that QALYs, being a health status index, do not stem directly from the individual's utility function and thus only partly reflect the individual's true preferences. This might lead to the choice of the nonpreferred alternative due to the misrepresentation of the individual's preferences. Two examples illustrate this claim. An alternative measure of outcome, the healthy-years equivalent (HYE), is described. This measure stems directly from the individual's utility function and thus fully reflects his/her preferences. It combines outcomes of both morbidity and mortality and thus can serve as common unit of measure for all programs, allowing comparisons across programs. Different ways of measuring the HYE are discussed.