Qaly

Part of speech: noun

Definitions

1. A unit used in health economics that measures a year of life weighted by the quality of health enjoyed during that year
2. A standard measure in healthcare evaluation where one full year of perfect health counts as one unit and lower-quality years count for less
3. An economic index combining the length of life with its quality, so that treatments can be compared by the healthy years they provide

Etymology: Unlike most words in this series, this one was built on purpose within living memory. It is an acronym for "quality-adjusted life year," a unit used in health economics to compare treatments by how much healthy life they add. A year lived in full health counts as one whole unit, while a year lived with illness or disability counts as a fraction, so a treatment that adds years of good health scores higher than one that merely prolongs a poor quality of life. The unit's blunt arithmetic is its interest. Two years of life at half quality count as one QALY, the same as one year at full quality. Because it reduces very different outcomes to a single number, it is used by health agencies to decide which treatments to fund, which is why it attracts both praise for consistency and criticism for putting a numerical value on a life. The abbreviation is usually pronounced as a word, "kwally," rather than letter by letter.