Utilities and Quality-Adjusted Life Years

TLDR

Utilities are designed for individual decision‑making under uncertainty, while QALYs aggregate health improvements across a group by combining life‑quantity and life‑quality gains. This review examines utilities and QALYs, focusing on their application in technology assessment and outlining their interrelationship. The article traces the historical development, assumptions, strengths, and weaknesses of utilities and QALYs, noting that utilities serve as quality‑adjustment weights for QALYs and together form the basis of cost‑utility analysis.

Abstract

Utilities and quality-adjusted life years (QALYs) are reviewed, with particular focus on their use in technology assessment. This article provides a broad overview and perspective on these two techniques and their interrelationship, with reference to other sources for details of implementation. The historical development, assumptions, strengths/weaknesses, and applications of each are summarized. Utilities are specifically designed for individual decision-making under uncertainty, but, with additional assumptions, utilities can be aggregated across individuals to provide a group utility function. QALYs are designed to aggregate in a single summary measure the total health improvement for a group of individuals, capturing improvements from impacts on both quantity of life and quality of life– with quality of life broadly defined. Utilities can be used as the quality-adjustment weights for QALYs; they are particularly appropriate for that purpose, and this combination provides a powerful and highly useful variation on cost-effectiveness analysis known as cost-utility analysis.