手法を比較

	Active Life Expectancy Estimation	Sullivan Method
分野	Social Gerontology	人口学
系統	Survival analysis	Survival analysis
提唱年	1983	1971
提唱者	Sidney Katz, Laurence G. Branch and colleagues	Daniel F. Sullivan
種類	Life-table estimator partitioning remaining life into active and dependent years	Prevalence-based health expectancy estimator
原典	Katz, S., Branch, L. G., Branson, M. H., Papsidero, J. A., Beck, J. C., & Greer, D. S. (1983). Active life expectancy. New England Journal of Medicine, 309(20), 1218-1224.	Sullivan, D. F. (1971). A single index of mortality and morbidity. HSMHA Health Reports, 86(4), 347–354.
別名	ALE, Disability-Free Years Expectancy, Independent Life Expectancy, Active vs Dependent Life Years	Sullivan's Index, Sullivan Health Expectancy Method, Prevalence-Based Health Expectancy, Sullivan Yöntemi
関連	4	4
概要	Active life expectancy (ALE) estimates how many of an older person's remaining years are expected to be lived in an active, independent state — free of disability in basic activities of daily living — as opposed to a dependent state requiring help. Introduced by Sidney Katz, Laurence Branch, and colleagues in 1983 in the New England Journal of Medicine, it answered a question that ordinary life expectancy cannot: not just how long people live, but how much of that life is lived in good functional health. The method combines age-specific mortality with the prevalence or transitions of ADL disability within a life-table framework, partitioning total remaining life into active and dependent components that sum to overall life expectancy. Katz and colleagues showed, using data from older adults in Massachusetts, that active life expectancy declines faster than total life expectancy with age and differs across groups. The concept reframed the goal of aging policy from merely extending lifespan to extending the active, independent portion of it. It launched the broader field of health expectancy measures and remains foundational to studying the compression or expansion of late-life morbidity.	The Sullivan method is a simple, widely used technique for estimating health expectancy — the average number of years a person can expect to live in a given health state, such as free of disability. Introduced by Daniel Sullivan in 1971, it combines an ordinary period life table with the observed age-specific prevalence of the health state, partitioning life-table person-years into healthy and unhealthy years without requiring any longitudinal transition data.