- Quality-adjusted life-years (QALYs) are used in cost-effectiveness analyses to aid coverage and reimbursement decisions worldwide. QALYs provide a flexible and convenient metric for measuring and comparing health outcomes across diverse diseases and treatments. But their use has stirred controversy about how accurately they reflect preferences for health care and whether their use is fair. We review the debate and the use of QALYs in other countries and discuss prospects for using them in the U.S. health care system. Strict adherence to a QALY approach is likely to prove unacceptable in the United States, but a more flexible use of QALYs could be beneficial.