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Three measures of longevity: time trends and record values
1Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Room E4634, Baltimore, MD 21205, USA. vcanudas@jhsph.edu
Demography
|July 9, 2010
Summary
This study tracks longevity measures like life expectancy and age at death. Record life expectancy has risen significantly, driven by reduced adult mortality in recent decades.
Area of Science:
- Demography
- Public Health
- Gerontology
Background:
- Understanding population longevity trends is crucial for public health and policy.
- Life expectancy at birth is a common metric, but median and modal ages at death offer deeper insights into mortality patterns.
Purpose of the Study:
- To analyze historical trends in life expectancy at birth, median age at death, and modal age at death.
- To investigate the factors driving changes in these longevity measures over time.
- To explain the previously observed uninterrupted increase in record life expectancy.
Main Methods:
- Analysis of historical demographic data on life expectancy at birth, median age at death, and modal age at death.
- Examination of trends in record values for these longevity indicators.
- Comparative analysis of changes in child versus adult mortality reductions.
Main Results:
- Record life expectancy at birth increased from 44 years (Sweden, 1840) to 82 years (Japan, 2005).
- Record median age at death shows a similar increasing pattern to life expectancy.
- Record modal age at death remained stable until the late 20th century, then increased, mirroring mean and median age trends.
Conclusions:
- The shift in the record modal age at death explains the sustained rise in record life expectancy.
- The primary driver of increased longevity has shifted from reductions in child mortality to reductions in adult mortality.
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