Health Utility Quality of Life and Care Measure Quality-Adjusted Life Year (QALY) QALY no Multiple countries and cultural groups QALYs are used primarily to correct a person's life expectancy based on the levels of health-related quality of life they are predicted to experience throughout the course of their life, or part of it. Self; Proxy Few but definitions not specific enough The number of QALYs lived by an individual in one year is simply: QALYs lived in one year = 1 * Q with Q <= 1; where Q is the health-related quality of life weight attached to the relevant year of life. I.e. QALY assumes a utility value (quality of life) of 1 = perfect health and a utility value of 0 = dead: Years of Life x Utility Value = Number of QALYs. E.g. If a person lives in perfect health for one year, that person will have 1 QALY (1 Year of Life x 1 Utility Value = 1 QALY), If a person lives in perfect health but only for half a year, that person will have 0.5 QALYs (0.5 Years of Life x 1 Utility Value = 0.5 QALYs) OR if a person lives for 1 year in a situation with 0.5 utility (half of perfect health), that person will also have 0.5 QALYs (1 Year of Life x 0.5 Utility Value = 0.5 QALYs). In cost-effectiveness evaluations the QALY is used to quantify the effectiveness of, for instance, a new medication versus the current one. In other words, the current standard of care is taken as the baseline, and the QALYs gained from the new (improved) intervention are counted in addition. Children and adults Standard global assessment of health interventions, also used in SCD studies All Quality-Adjusted Life Year