Advances in life sciences that are predicted in the 21st century will present many challenges for health professionals and policy-makers. The major questions will be how to allocate resources to pay for costs of new technologies and who will best benefit from advances in new diagnostic and treatment methods. We review in this paper the concept of utility and how it can be applied and expanded to provide data to help health professionals make decisions that are preferred by patients and the public at large. Utility is a measure of people's well-being or preferences for outcomes. The measurement of utilities of a new diagnostic technology, for example, can be carried out with the use of simple methods that do not incorporate all of the uncertainties and potential outcomes associated with providing the test, or with more complex methods that can incorporate most uncertainties. This review describes and critiques the different measurement methods of utilities.