Comparer des méthodes

	DALY Computation	Healthy Life Expectancy Decomposition
Domaine	Global Health	Social Epidemiology
Famille	Process / pipeline	Process / pipeline
Année d'origine	1994	2004
Auteur d'origine	Christopher J. L. Murray; Christopher J. L. Murray & Alan D. Lopez	Wilma J. Nusselder & Caspar W. N. Looman; Daniel F. Sullivan
Type	Composite burden-of-disease metric pipeline	Demographic decomposition pipeline for a health-expectancy difference
Source fondatrice	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.	Nusselder, W. J., & Looman, C. W. N. (2004). Decomposition of differences in health expectancy by cause. Demography, 41(2), 315-334.
Alias	Disability-Adjusted Life Years, Burden of Disease Computation, YLL plus YLD, GBD DALY Calculation	Health Expectancy Decomposition, Nusselder-Looman Decomposition, Decomposition of Disability-Free Life Expectancy, Mortality and Disability Decomposition of Health Expectancy
Apparentées	3	4
Résumé	The disability-adjusted life year, or DALY, is the central metric of the global burden of disease, expressing the total health loss from a disease, injury, or risk factor as a single time-based number. One DALY is one healthy year of life lost. The metric, developed by Christopher Murray and elaborated with Alan Lopez in the 1990s, combines two distinct kinds of loss on a common scale: the years of life lost when people die earlier than a reference life expectancy, and the years of healthy life lost when people live with illness or disability rather than in full health. By weighting time lived in poor health by its severity and adding it to time lost to premature death, the DALY makes it possible to compare conditions as different as a fatal cancer and a chronic non-fatal disease, and to rank causes of ill health across populations in a way mortality statistics alone cannot.	Healthy (or disability-free) life expectancy combines how long people live with how much of that life is spent in good health, and differences in it between groups or over time reflect two distinct forces: changes in mortality and changes in the prevalence of disability. Healthy-life-expectancy decomposition separates these forces. Building on the Sullivan method — which weights life-table person-years by the age-specific share of life lived without disability — Wilma Nusselder and Caspar Looman's 2004 method splits the gap in health expectancy between two populations into an additive mortality component and a disability component for each age, and can further attribute each to specific causes. This resolves the central interpretive ambiguity of health expectancy: a population can have higher healthy life expectancy because its people die later, because they are less disabled at each age, or both, and only a decomposition can tell which.