Life expectancy and disparity: an international comparison of life table data
- 1Max Planck Institute for Demographic Research, Rostock, Germany
- 2Department of Public Health, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, the Netherlands
- Correspondence to James W Vaupel;
- Received 23 March 2011
- Accepted 17 June 2011
- Published 29 July 2011
Objectives To determine the contribution of progress in averting premature deaths to the increase in life expectancy and the decline in lifespan variation.
Design International comparison of national life table data from the Human Mortality Database.
Setting 40 developed countries and regions, 1840–2009.
Population Men and women of all ages.
Main outcome measure We use two summary measures of mortality: life expectancy and life disparity. Life disparity is a measure of how much lifespans differ among individuals. We define a death as premature if postponing it to a later age would decrease life disparity.
Results In 89 of the 170 years from 1840 to 2009, the country with the highest male life expectancy also had the lowest male life disparity. This was true in 86 years for female life expectancy and disparity. In all years, the top several life expectancy leaders were also the top life disparity leaders. Although only 38% of deaths were premature, fully 84% of the increase in life expectancy resulted from averting premature deaths. The reduction in life disparity resulted from reductions in early-life disparity, that is, disparity caused by premature deaths; late-life disparity levels remained roughly constant.
Conclusions The countries that have been the most successful in averting premature deaths have consistently been the life expectancy leaders. Greater longevity and greater equality of individuals' lifespans are not incompatible goals. Countries can achieve both by reducing premature deaths.
To cite: Vaupel JW, Zhang Z, van Raalte AA. Life expectancy and disparity: an international comparison of life table data. BMJ Open 2011;1:e000128. doi:10.1136/bmjopen-2011-000128
Funding This work was supported by the Max Planck Society and the US National Institute on Ageing (NIA P01-08761).
Competing interests None.
Contributors JWV conceived the research idea and co-wrote the drafts, ZZ managed the data analysis and commented on the drafts, and AAvR contributed to data analysis and co-wrote the drafts. All authors approved the final manuscript.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement Data from the Human Mortality Database are freely available at http://www.mortality.org.
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