This is an outcome measure of health care devised by health economists in the 1980s, and stands for Quality Adjusted Life Year. It takes a year of healthy life expectancy to be worth a grade of 1, and a year of unhealthy life expectancy to be worth less than 1. The worse the forecast of an unhealthy person's quality of life, the lower will be his or her rating. If someone is expected to live for five years in a healthy state, the grading will be 5; ten years of life estimated to be only 25 per cent healthy will rate as 2.5. The measure has proved controversial but is an indication of the likely cost-effectiveness of a particular treatment, and can contribute to assessing whether or not a proposed or actual treatment or procedure is worthwhile – both for patients and for the economy. Other health economic outcomes used in assessing treatments include HALE (health-adjusted life expectancy) and HRQOL (Health-Related Quality of Life).