Health Adjusted Life Years Definition

The disability adjusted life year daly is a measure of overall disease burden expressed as the number of years lost due to ill health disability or early death it was developed in the 1990s as a way of comparing the overall health and life expectancy of different countries.

Health adjusted life years definition. Health adjusted life years are a measurement of the health of a population typically used in estimates of the burden of disease. One qaly equates to one year in perfect health. They permit comparisons between illnesses or interventions as well as between populations 1.

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. The daly is becoming increasingly common in the field of public health and health impact assessment hia. So far our measure is similar to the haly except that we have re interpreted period specific quality of life as oqol rather than hrqol and have potentially allowed scores greater than one in addition to below zero which is already the case with the haly.

They combine the effects of disability or disease morbidity and death mortality simultaneously. Health adjusted life years halys are summary measures of population health used in burden of disease estimates. In the gbd study the disability adjusted life years daly was used as the unit of measure to quantify the impact of dise ases on population health.

They are the most frequently cited metrics for risk benefit assessment. Qalys quality adjusted life year and dalys disability adjusted life year are common terms used within this framework. It is used in economic evaluation to assess the value of medical interventions.

Qalys are a measure of years lived in perfect health gained whereas dalys are a measure of years in perfect health lost. Th e daly measure belongs to the family of halys and was thus considered qualified to comprehensively assess the global burden of disease. It adjusts overall life expectancy by the amount of time lived in less than perfect health.

Halys are used to measure the combined effects of mortality and morbidity in populations. Quality adjusted life year qaly. The most widely used approach for estimating quality of life benefits in economic evaluations is the quality adjusted life year qaly.