A measure of the state of health of a person or group of people in which the benefits, in terms of length of life, are adjusted to reflect the quality of life. That is, a year of active normal life gained as the result of a treatment is rated higher than a year of living with reduced quality (such as being in extreme pain or being in hospital).
It is often measured in terms of the level of a person’s ability to perform activities of daily living, their freedom from pain and mental disturbance. The patients, or observers with knowledge in the area, rate these various states by giving them scores. HTAI