an evaluation of the protocol of guaiac tests for colon cancer estimates the costs per cancer detected. Cost–utility analysis is a form of cost–effectiveness analysis where the effect or outcome of health interventions are measured in a common metric based on people’s utility levels or preferences over different health states. Probably the most popular common unit of measurement is the QALY, but there are other variants, including the healthy year equivalent (HYE) and the disability-adjusted life year (DALY). Using a common metric allows comparisons of a wide range of interventions.