手法を比較

	Years of Life Lost	Healthy Life Expectancy
分野	人口学	人口学
系統	Process / pipeline	Survival analysis
提唱年	1994	1971
提唱者	Premature-mortality measure; standardized form by Christopher Murray (Global Burden of Disease)	Daniel F. Sullivan (Sullivan method); developed by the WHO/REVES tradition
種類	Burden-of-disease measure of life-years lost to early death	Health-expectancy estimator partitioning life expectancy into healthy and unhealthy years
原典	Murray, C. J. L. (1994). Quantifying the burden of disease: the technical basis for disability-adjusted life years. Bulletin of the World Health Organization, 72(3), 429–445.	Sullivan, D. F. (1971). A single index of mortality and morbidity. HSMHA Health Reports, 86(4), 347–354.
別名	YLL, Years of Potential Life Lost, Premature Mortality Years Lost	HALE, Health-Adjusted Life Expectancy, Disability-Free Life Expectancy
関連	4	4
概要	Years of life lost (YLL) measures the burden of premature mortality by counting, for every death, how many additional years the person could have expected to live had they survived to a reference life expectancy. Summed over all deaths, YLL turns a count of deaths into a count of lost life-years, so that deaths at young ages weigh far more heavily than deaths in old age. It is the mortality half of the disability-adjusted life year (DALY) and a core metric of the Global Burden of Disease studies, letting analysts rank diseases and injuries by how much potential life they destroy rather than merely by how many people they kill.	Healthy life expectancy partitions ordinary life expectancy into the years a person can expect to live in good health and the years expected to be lived with disability or ill health. Building on the life table, the classic Sullivan method weights each age interval's person-years by the prevalence of good health, so the resulting expectancy answers not just 'how long will people live?' but 'how many of those years will be healthy?'. It has become a headline summary of population health, reported by the World Health Organization as HALE and tracked alongside life expectancy to judge whether longer lives are also healthier lives.