Title: Mortality Measurement at Advanced Ages: A Study of the Social Administration Death Master File
1Mortality Measurement at Advanced Ages A Study
of the Social Administration Death Master File
- Dr. Leonid A. Gavrilov, Ph.D.
- Dr. Natalia S. Gavrilova, Ph.D.
-
- Center on Aging
- NORC and The University of Chicago
- Chicago, Illinois, USA
2What Do We Know About Mortality of Centenarians?
3A Study That Answered This Question
4M. Greenwood, J. O. Irwin. BIOSTATISTICS OF
SENILITY
5Mortality at Advanced Ages
- Source Gavrilov L.A., Gavrilova N.S. The
Biology of Life Span - A Quantitative Approach, NY Harwood Academic
Publisher, 1991
6Mortality Deceleration in Other Species
- Invertebrates
- Nematodes, shrimps, bdelloid rotifers, degenerate
medusae (Economos, 1979) - Drosophila melanogaster (Economos, 1979
Curtsinger et al., 1992) - Medfly (Carey et al., 1992)
- Housefly, blowfly (Gavrilov, 1980)
- Fruit flies, parasitoid wasp (Vaupel et al.,
1998) - Bruchid beetle (Tatar et al., 1993)
- Mammals
- Mice (Lindop, 1961 Sacher, 1966 Economos, 1979)
- Rats (Sacher, 1966)
- Horse, Sheep, Guinea pig (Economos, 1979 1980)
- However no mortality deceleration is reported for
- Rodents (Austad, 2001)
- Baboons (Bronikowski et al., 2002)
7Mortality Leveling-Off in House Fly Musca
domestica
- Our analysis of the life table for 4,650 male
house flies published by Rockstein Lieberman,
1959. - Source
- Gavrilov Gavrilova. Handbook of the Biology of
Aging, Academic Press, 2006, pp.3-42.
8Existing Explanations of Mortality Deceleration
- Population Heterogeneity (Beard, 1959 Sacher,
1966). sub-populations with the higher injury
levels die out more rapidly, resulting in
progressive selection for vigour in the surviving
populations (Sacher, 1966) - Exhaustion of organisms redundancy (reserves) at
extremely old ages so that every random hit
results in death (Gavrilov, Gavrilova, 1991
2001) - Lower risks of death for older people due to less
risky behavior (Greenwood, Irwin, 1939) - Evolutionary explanations (Mueller, Rose, 1996
Charlesworth, 2001)
9Challenges in Hazard Rate Estimation At Extremely
Old Ages
- Mortality deceleration may be an artifact of
mixing different birth cohorts with different
mortality (heterogeneity effect) - Standard assumptions of hazard rate estimates may
be invalid when risk of death is extremely high - Ages of very old people may be highly exaggerated
10Social Security Administration Death Master File
Helps to Relax the First Two Problems
- Allows to study mortality in large, more
homogeneous single-year or even single-month
birth cohorts - Allows to study mortality in one-month age
intervals narrowing interval of hazard rates
estimation
11What Is SSA DMF ?
- SSA DMF is a publicly available data resource
(available at Rootsweb.com) - Covers 93-96 percent deaths of persons 65
occurred in the United States in the period
1937-2007 - Some birth cohorts covered by DMF could be
studied by method of extinct generations - Considered superior in data quality compared to
vital statistics records by some researchers
12Social Security Administration Death Master File
(DMF) Was Used in This Study
(1) Study of cohort mortality at advanced ages
Estimation of hazard rates for each month of age
for extinct birth cohorts. (2) Month-of-birth and
mortality after age 80 Estimation of life
expectancy in real birth cohort according to
month of birth.
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14Quality Control
Study of mortality in states with better age
reporting Records for persons applied to SSN in
the Southern states, Hawaii and Puerto Rico were
eliminated
15Mortality when all data are used
16Mortality for data with presumably different
quality
17Mortality when all data are used
18Mortality for data with presumably different
quality
19Mortality for data with presumably different
quality
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21Mortality at Advanced Ages by Sex
22Mortality at Advanced Ages by Sex
23Mortality at Advanced Ages by Sex
24Mortality at Advanced Ages by Sex
25Mortality at Advanced Ages by Sex
26Mortality at Advanced Ages by Sex
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28Crude Indicator of Mortality Plateau (1)
- Linearity of survival curves in semi-log
coordinates (log survival age)
29Logarithm of Survival at Advanced Ages
30Crude Indicator of Mortality Plateau (2)
- Coefficient of variation for life expectancy
is close to, or higher than 100 - CV s/µ
- where s is a standard deviation and µ is
mean
31Coefficient of variation for life expectancy as a
function of age
32Month-of-Birth and Mortality at Advanced Ages
- SSA Death Master File allows researchers to study
mortality in real birth cohorts by month-of-birth - Provides more accurate and unbiased estimates of
life expectancy by month of birth compared to
usage of cross-sectional death certificates
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35Month-of-Birth effects disappear at age 100
36Conclusions
- Late-life mortality deceleration appears to be
not that strong - cohort mortality at advanced
ages continues to grow up to age 105 years - Late-life mortality plateau is likely not to be
an artifact and is expressed earlier in males
than females - Month of birth effects on mortality exist at age
80 but then fade and disappear by age 100
37Acknowledgments
- This study was made possible thanks to
- generous support from the
- National Institute on Aging
- The Society of Actuaries grant
- Stimulating working environment at the Center
on Aging, NORC/University of Chicago
38For More Information and Updates Please Visit Our
Scientific and Educational Website on Human
Longevity
- http//longevity-science.org
And Please Post Your Comments at our Scientific
Discussion Blog
- http//longevity-science.blogspot.com/
39Life expectancy at age 90
40Median lifespan at age 90
41Life expectancy at age 100
42Male life expectancy at age 90
43Female life expectancy at age 90