Quality-Adjusted Life Years, or QALYs, is a measure used to evaluate the value of medical interventions by combining both the quantity and quality of life. One QALY represents one year of life in perfect health. If a person lives for one year with a health condition that reduces their quality of life, that year may count as less than one QALY. QALYs help healthcare providers and policymakers assess the effectiveness of treatments and allocate resources efficiently. By comparing the QALYs gained from different interventions, they can make informed decisions about which treatments offer the best overall benefit to patients.