In economic evaluation of healthcare interventions utilities (also called health state preference values) are used to represent the strength of individuals’ preferences for different health states. When utility values are averaged over a population of responders they can be considered to be valuations of health states. Conventionally the valuations fall between 0 and 1, with 1 representing the valuation of a state of perfect health and 0 representing the valuation of death (non-existence). In some scoring systems a negative utility value is also possible, which indicates that a (very poor) health state is valued as less preferable than death. Sequences of utility values reported over periods of time for individual patients or cohorts of patients may be aggregated to derive quality-adjusted life years, commonly used as outcomes in economic evaluation. Several methods are used to obtain health state preference values (utilities). Direct methods involve individuals being asked to describe and assess health states and place weights on them, using techniques such as Standard Gamble or Time Trade-off. Indirect methods involve the use of generic multi-attribute scoring systems to classify health states according to a number of distinct domains. Utility tariffs for health states described in this way are derived from population surveys. Study subjects are asked to describe their health status at different time points using these systems, and their responses are converted to utilities by using the appropriate tariff. Generic multi-attribute scoring systems are preferred to disease-specific ones as they cover general aspects of health and can facilitate comparisons across different disease areas. The most commonly used multi-attribute utility instrument is EQ-5D (preferred by UK NICE), which has domains of mobility, self-care, usual activities, pain/discomfort and anxiety/depression.
How to cite: Utility [online]. (2016). York; York Health Economics Consortium; 2016. https://yhec.co.uk/glossary/utility/