방법 비교

	Active Life Expectancy Estimation	Multistate Life Table
분야	Social Gerontology	인구학
계열	Survival analysis	Survival analysis
기원 연도	1983	1975
창시자	Sidney Katz, Laurence G. Branch and colleagues	Andrei Rogers, Robert Schoen and collaborators
유형	Life-table estimator partitioning remaining life into active and dependent years	Nonparametric life table with multiple living states and transitions
원전	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.	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 9781557864512
별칭	ALE, Disability-Free Years Expectancy, Independent Life Expectancy, Active vs Dependent Life Years	Increment-Decrement Life Table, Multiple-State Life Table, Multistate Demography, Çok Durumlu Yaşam Tablosu
관련	4	4
요약	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 multistate life table, also called the increment-decrement life table, generalizes the ordinary life table to populations that move among several living states — such as healthy and disabled, married and unmarried, or employed and unemployed — as well as the absorbing state of death. Using age-specific transition rates organized in matrices, it tracks the flows of a synthetic cohort among states and yields state-specific expectancies, such as the years a person can expect to spend healthy versus disabled.