障害調整生存年数
- クリストファー・マーレイらが提唱した、傷病や障害の程度や期間によって重み付けをした生存年数の指標
- 集団における疾病負荷や介入効果の尺度として、QALYの変わりに提唱され、集団の健康の妥当な指標と言われる。
- 生命損失年齢に障害損失年齢を加味する事で、死亡と障害を含む包括的な保健指標となるが、算出困難で、障害の重み付けなど多くの仮定が必要
- YLL(Years of Life Lost)：(死亡数) x (年齢階層別)平均余命
- YLD(Years Lost due to Disability)：(障害発生数) x (障害の重度) x (余命の損失年数)
- wikipedia
- The disability-adjusted life year (DALY) is a measure of overall disease burden. Originally developed by the World Health Organization, it is becoming increasingly common in the field of public health and health impact assessment (HIA). It "extends the concept of potential years of life lost due to premature death...to include equivalent years of ‘healthy’ life lost by virtue of being in states of poor health or disability."[2] In so doing, mortality and morbidity are combined into a single, common metric.
- Traditionally, health liabilities were expressed using one measure: (expected or average number of) Years of Life Lost (YLL). This measure does not take the impact of disability into account, which can be expressed by: Years Lived with Disability (YLD). DALYs are calculated by taking the sum of these two components. In a formula:
- The DALY relies on an acceptance that the most appropriate measure of the effects of chronic illness is time, both time lost due to premature death and time spent disabled by disease. One DALY, therefore, is equal to one year of healthy life lost. Japanese life expectancy statistics are used as the standard for measuring premature death, as the Japanese have the longest life expectancies.
- Looking at the burden of disease via DALYs can reveal surprising things about a population's health. For example, the 1990 WHO report indicated that 5 of the 10 leading causes of disability were psychiatric conditions. Psychiatric and neurologic conditions account for 28% of all years lived with disability, but only 1.4% of all deaths and 1.1% of years of life lost. Thus, psychiatric disorders, while traditionally not regarded as a major epidemiological problem, are shown by consideration of disability years to have a huge impact on populations.