*** Welcome to piglix ***

Quality-adjusted life year


The quality-adjusted life year or quality-adjusted life-year (QALY) is a generic measure of disease burden, including both the quality and the quantity of life lived. It is used in economic evaluation to assess the value for money of medical interventions. One QALY equates to one year in perfect health. If an individual's health is below this maximum, QALYs are accrued at a rate of less than 1 per year. To be dead is associated with 0 QALYs, and in some circumstances it is possible to accrue negative QALYs to reflect health states deemed 'worse than dead'.

The QALY is often used in cost-utility analysis in order to estimate the cost-per-QALY associated with a health care intervention. This incremental cost-effectiveness ratio (ICER) can then be used to allocate healthcare resources, often using a threshold approach.

In the United Kingdom, the National Institute for Health and Care Excellence, which advises on the use of health technologies within the National Health Service, has since at least 2013 used "£ per QALY" to evaluate their utility.

The concept of the QALY is credited to work by Klarman and later Fanshel and Bush and Torrance who suggested the idea of length of life adjusted by indices of functionality or health. It was officially named the QALY in print in an article by Zeckhauser and Shepard It was later promoted through medical technology assessment conducted by the US Congress Office of Technology Assessment.

Then, in 1980, Pliskin proposed a justification of the construction of the QALY indicator using the multiattribute utility theory: if a set of conditions pertaining to agent preferences on life years and quality of life are verified, then it is possible to express the agent’s preferences about couples (number of life years/health state), by an interval (Neumannian) utility function. This utility function would be equal to the product of an interval utility function on « life years », and an interval utility function on « health state ». According to Pliskin et al., The QALY model requires utility independent, risk neutral, and constant proportional tradeoff behaviour. Because of these theoretical assumptions, the meaning and usefulness of the QALY is debated. Perfect health is hard, if not impossible, to define. Some argue that there are health states worse than being dead, and that therefore there should be negative values possible on the health spectrum (indeed, some health economists have incorporated negative values into calculations). Determining the level of health depends on measures that some argue place disproportionate importance on physical pain or disability over mental health.


...
Wikipedia

...