Quality adjusted life year
- Slovak term: Slovenský termín
- A year of life adjusted for its quality, value or utility (WHO 2009).
- The arithmetic product of life expectancy and a measure of the quality of the remaining life years (WHO et al. 2003).
- A year of potential life adjusted based on a consideration of the quality of life at various stages (Symons et al. 2000).
Explanation
One year in full health is given the value of 1 QALY; the same period in moderate pain, for example, might be given a value of 0.7 QALY. The QALY aims to incorporate quality of life and quantity of life in one measure, and so is attractive to health economists as a general measure of health outcome (WHO 2009).
QALY places a weight on time in different health states. A year of perfect health is worth 1; however, a year of less than perfect health life expectancy is worth less than 1. Death is considered to be equivalent to 0, however, some health states may be considered worse than death and have negative scores. QALYs provide a common currency to assess the extent of the benefits gained from a variety of interventions in terms of health-related quality of life and survival for the patient (WHO et al. 2003).
Because of the measure of a quality-adjusted life year can vary from investigator to investigator, knowing how the quality has been determined in calculating quality-adjusted life years lost is important (Symons et al. 2000).
Example
References
- WHO (2009) WHO handbook on indoor radon : a public health perspective.
- WHO, WMO and UNEP (2003) Climate change and human health: Risks and responses.
- Symons, J. M., Bradley, L. C. Jr. and Cleveland, T. C. 2000. The Drinking Water Dictionary. American Water Works Association
Links
- WHO — The Health and Environment Lexicon
- [Global environmental change web site]
