Healthcare systems must address diverse health conditions for diverse types of patients, yet their resources are limited. Utility is a concept that allows health economists to weigh or prioritise certain interventions according to what the target population prefers and considers fair. Utilities consider the trade-offs or opportunity costs that the target population must make to gain one unit of health benefit.

To build economic models, assume that utilities can be added over time and they use Quality-Adjusted Life Years (QALYs) to measure them as recommended by the National Institute for Health and Care Excellence (NICE) (See NICE Manual for further details).