Preferences of states of health and measurements of utility

Abstract

Measurements of health states values, preferences and utility estimate the degree or convenience of a health state against an external instrument. They are generic measurements of health-related quality of life (HRQL), that summarize its value in one single number between 0 (zero) and 1 (one). Measurements of preferences of health states and of utility differ from general and specific measurements obtained by means of questionnaires of HRQL in three important areas: 1. They estimate individual preferences by alternatives. 2. They provide a comprehensive result of HRQL. 3. They offer a common unit of analysis. Two methods for measuring utility are available: direct and indirect. They are also known as multi-attribute utilities or classification systems for health states. The direct measurement process consists of an aggregate of descriptions that the interviewer presents to the surveyed individuals. For indirect measurements only questionnaires are applied. This article describes the main methods for evaluation of utilities in order to make known the outcomes presently used in both HRQL studies and economic evaluations.