QALY (Quality-Adjusted Life Year)

A QALY, or Quality-Adjusted Life Year, is a way to measure the value of healthcare interventions by combining both the quantity and quality of life they provide. One QALY equals one year of life in perfect health. If a treatment extends life but with some health issues, the additional years are weighted to reflect the reduced quality of life. For example, two years with some health problems might count as less than two full years of perfect health. QALYs help compare the benefits of different medical treatments in terms of both longevity and well-being.