The calculation of QALY involves determining the number of years a patient is expected to live after receiving a treatment and adjusting these years by the quality of life experienced during that time. Quality of life is usually assessed on a scale from 0 to 1, where 0 represents death and 1 represents perfect health. For instance, if a cancer treatment provides an additional 2 years of life at a quality of life score of 0.8, the QALY would be 1.6.
