Understanding DALYs (disability-adjusted life years).

The measurement unit disability-adjusted life years (DALYs), used in recent years to quantify the burden of diseases, injuries and risk factors on human populations, is grounded on cogent economic and ethical principles and can guide policies toward delivering more cost-effective and equitable health care. DALYs follow from a fairness principle that treats 'like as like' within an information set comprising the health conditions of individuals, differentiated solely by age and sex. The particular health state weights used to account for non-fatal health outcomes are derived through the application of various forms of the person trade-off.