Quality-adjusted life year

From Opasnet
(Redirected from QALY)
Jump to: navigation, search
Progression class
In Opasnet many pages being worked on and are in different classes of progression. Thus the information on those pages should be regarded with consideration. The progression class of this page has been assessed:
This page is a draft
The relevat content and structure of the page is already present, but there still is a lot of missing content.
The content and quality of this page is being curated by THL. THL LOGO EN WEB 272x66px.jpg

The quality was last checked: 2016-04-09.


Question

How should quality-adjusted life years (QALY) be measured?

Answer

QALY = \sum_i L_i U_i,

where i is an index of all different time periods, L is the duration of a time period, and U is the utility of health during that time perios (1 = perfect health, 0 = death). QALYs can be calculated for a single person or a population.

Rationale

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 QALY is a measure of the value of health outcomes. Since health is a function of length of life and quality of life, the QALY was developed as an attempt to combine the value of these attributes into a single index number. The basic idea underlying the QALY is simple: it assumes that a year of life lived in perfect health is worth 1 QALY (1 Year of Life × 1 Utility value = 1 QALY) and that a year of life lived in a state of less than this perfect health is worth less than 1. In order to determine the exact QALY value, it is sufficient to multiply the utility value associated with a given state of health by the years lived in that state. QALYs are therefore expressed in terms of "years lived in perfect health": half a year lived in perfect health is equivalent to 0.5 QALYs (0.5 years × 1 Utility), the same as 1 year of life lived in a situation with utility 0.5 (e.g. bedridden) (1 year × 0.5 Utility). QALYs can then be incorporated with medical costs to arrive at a final common denominator of cost/QALY. This parameter can be used to develop a cost-effectiveness analysis of any treatment. Therefore,

QALY is similar to disability-adjusted life year, but the methods of calculation differ.

See also

References