A statistical term used as a measure in clinical trials. Quality Adjusted Life Year is a measure of the value of a year of life in relation to health (a QALY of 1 means a year of full health). QUALY is the unit of calculation often used to "convert" the benefits of medical interventions so that the benefits of different interventions can be better compared. It should be noted that the benefit is calculated on the basis of a model. The "deduction" in the benefit due to only partial success of the treatment, side effects, etc. can be determined by patient questioning or experts. In the case of compulsory health insurance, QUALY is often used: How much may a year of life in full health cost?