Thursday, February 20, 2014

New Longevity Study of Old-Age Survival

Greetings,

 We are pleased to alert you about our new article on old-age mortality, published this week by peer-reviewed scientific journal.  This article refutes a common belief in old-age mortality deceleration, mortality leveling-off, and mortality plateaus.

 Here is the full reference to the article for future possible citations:

Biodemography of Old-Age Mortality in Humans and Rodents
Natalia S. Gavrilova; Leonid A. Gavrilov
The Journals of Gerontology Series A: Biological Sciences and Medical Sciences 2014;
doi: 10.1093/gerona/glu009; PMID: 24534516 [Published online ahead of print], 9 pages

Full text is available at:
http://biomedgerontology.oxfordjournals.org/content/early/2014/02/16/gerona.glu009
Shorter link:
http://tinyurl.com/Old-Age-Mortality-2014

Feel free to contact us for complimentary PDF file of this article, if you have any problems using the provided links.

Comments and suggestions are most welcome!

Thank you, and looking forward to hear from you.

Kind regards,

-- Leonid  and  Natalia

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-- Leonid Gavrilov, Ph.D., GSA Fellow
-- Natalia Gavrilova, Ph.D., GSA Fellow
Center on Aging, NORC at the University of Chicago
Website: http://longevity-science.org/


P.S.:  Here is the abstract of the new article:

Abstract:

The growing number of persons living beyond age 80 underscores the need for accurate measurement of mortality at advanced ages and understanding the old-age mortality trajectories.  It is believed that exponential growth of mortality with age (Gompertz law) is followed by a period of deceleration, with slower rates of mortality increase at older ages.  This pattern of mortality deceleration is traditionally described by the logistic (Kannisto) model, which is considered as an alternative to the Gompertz model.  Mortality deceleration was observed for many invertebrate species, but the evidence for mammals is controversial.

We compared the performance (goodness-of-fit) of two competing models ­-- the Gompertz model and the logistic (Kannisto) model using data for three mammalian species: 22 birth cohorts of U.S. men and women,  eight cohorts of laboratory mice, and 10 cohorts of laboratory rats.  For all three mammalian species, the Gompertz model fits mortality data significantly better than the “mortality deceleration” Kannisto model (according to the Akaike’s information criterion as the goodness-of-fit measure).  These results suggest that mortality deceleration at advanced ages is not a universal phenomenon, and survival of mammalian species follows the Gompertz law up to very old ages.

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