Childhood Conditions and Exceptional Longevity

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Childhood Conditions and Exceptional Longevity

• Dr. Leonid A. Gavrilov, Ph.D.
• Dr. Natalia S. Gavrilova, Ph.D.
• Center on Aging
• NORC and The University of Chicago
• Chicago, Illinois, USA

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Centenarians represent the fastest growing age
group in the industrialized countries

• Yet, factors predicting exceptional longevity and
  its time trends remain to be fully understood
• In this study we explored the new opportunities
  provided by the ongoing revolution in information
  technology, computer science and Internet
  expansion to explore early-childhood predictors
  of exceptional longevity

Jeanne Calment (1875-1997)
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Revolution in Information TechnologyWhat does
it mean for longevity studies?

• Over 75 millions of computerized genealogical
  records are available online now!

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Computerized genealogies is a promising source of
information about potential predictors of
exceptional longevity life-course events,
early-life conditions and family history of
longevity
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Computerized Genealogies as a Resource for
Longevity Studies

• Pros provide important information about family
  and life-course events, which otherwise is
  difficult to collect (including information about
  lifespan of parents and other relatives)
• Cons Uncertain data quality
  Uncertain validity and generalizability
  

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For longevity studies the genealogies with
detailed birth dates and death dates for
long-lived individuals (centenarians) and their
relatives are of particular interest

• In this study 1,001 genealogy records for
  centenarians born in 1875-1899 were collected and
  used for further age validation

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Internet Resources Used in Centenarian Age
Verification

• Social Security Administration Death Master File
  is publicly available at the Rootsweb website
  http//ssdi.rootsweb.com/cgi-bin/ssdi.cgi
• Head of household indexes and census page images
  for 1900, 1920 and 1910 federal censuses are
  provided by Genealogy.com
• Individual indexes of enumerated persons by 1900,
  1920 and 1930 federal censuses and census page
  images are provided by Ancestry.com

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Steps of Centenarian Age Verification

1. Internal consistency checks of dates
2. Verification of death dates linkage to the
   Social Security Administration Death Master File
   (DMF)
3. Verification of birth dates linkage to early
   Federal censuses (1900, 1910, 1920, 1930)

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A typical image of centenarian family in 1900
census
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Results of Centenarian Age Verification
1001 records consistency checks 990 records used for further verification
990 records were linked to the SSA Death Master File Linkage success rate 77 (80 for centenarians born after 1890) In 3 of cases centenarian status was not confirmed
548 records found in DMF for persons born in 1890-1899 were then linked to early US censuses Linkage success rate 80 when using Genealogy.com and 91 after supplementation with Ancestry.com. In 8 of cases a 1-year disagreement between genealogy and census record was observed
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Conclusions of the Age Verification Study

• Death dates of centenarians recorded in
  genealogies always require verification because
  of strong outliers (1.3, misprints)
• Birth dates of centenarians recorded in
  genealogies are sufficiently accurate - 92 are
  correct for the remaining 8 only one-year
  disagreements
• Quality of genealogical data is good enough if
  these data are pre-selected for high data quality

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Birth Order and Chances to Become a Centenarian
Cases - 436 centenarians born in the United
States between 1890 and 1899 Controls their
siblings born in the same time window (1,119
controls) Model log(longevity odds ratio) ax
bx2 cz d where x birth order z family
size a,b,c,d parameters of polynomial
regression model
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Birth Order and Survival to 100
Source Gavrilova, N.S., Gavrilov, L.A. Search
for Predictors of Exceptional Human Longevity.
In Living to 100 and Beyond Monograph. The
Society of Actuaries, Schaumburg, Illinois, USA,
2005, pp. 1-49.
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New Developments
Can birth order effect be confirmed by more
rigorous approach a strictly within-family
analysis? Method of conditional logistic
regression allows us to compare centenarians with
their siblings within the same family. This
eliminates confounding caused by between-family
variation.
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First-born siblings are more likely to become
centenarians (odds 1.8)

• Conditional (fixed-effects) logistic regression
  Number of obs 950
• 
  LR chi2(2) 33.75
• 
  Prob gt chi2 0.0000
• Log likelihood -282.22348
  Pseudo R2 0.0564
• --------------------------------------------------
  --------------------
• Variable Odds Ratio Pgtz
  95 Conf. Interval
• -------------------------------------------------
  --------------------
• First-born status 1.772 0.006 1.180
  2.663
• Male sex .404 0.000 .284
  .576
• --------------------------------------------------
  -------------------------------

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Birth Order and Odds to Become a Centenarian
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Can the birth-order effect be a result of
selective child mortality, thus not applicable to
adults?

• Approach
• To compare centenarians with those siblings only
  who survived to adulthood (age 20)

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First-born adult siblings (20years) are more
likely to become centenarians (odds 1.95)

• Conditional (fixed-effects) logistic regression
  Number of obs 797
• 
  LR chi2(2) 27.54
• 
  Prob gt chi2 0.0000
• Log likelihood -247.93753
  Pseudo R2 0.0526
• --------------------------------------------------
  --------------------------------
• Variable Odds Ratio
  Pgtz 95 Conf. Interval
• -------------------------------------------------
  --------------------------------
• First-born status 1.949 0.003 1.261
  3.010
• Male sex .458 0.000 .318
  .658
• --------------------------------------------------
  --------------------------------

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Even at age 75 it still helps to be a first-born
child (odds 1.7)

• Conditional (fixed-effects) logistic regression
  Number of obs 557
• 
  LR chi2(2) 19.03
• 
  Prob gt chi2 0.0001
• Log likelihood -186.22869
  Pseudo R2 0.0486
• --------------------------------------------------
  --------------
• Variable Odds Ratio Pgtz 95
  Conf. Interval
• -------------------------------------------------
  --------------
• First-born status 1.659 0.040 1.022
  2.693
• Male sex .459 0.000 .306
  .687
• --------------------------------------------------
  --------------

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Are young fathers responsible for birth order
effect?

• Conditional (fixed-effects) logistic regression
  Number of obs 950
• 
  LR chi2(2) 30.11
• 
  Prob gt chi2 0.0000
• Log likelihood -284.04284
  Pseudo R2 0.0503
• --------------------------------------------------
  -------------------------
• Variable Odds Ratio Pgtz
  95 Conf. Interval
• -------------------------------------------------
  -------------------------
• Born to young father 1.856 0.056 .985
  3.496
• Male sex .415 0.000 .291
  .590
• --------------------------------------------------
  -------------------------

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Birth order is more important than paternal age
for chances to become a centenarian

• Conditional (fixed-effects) logistic regression
  Number of obs 950
• 
  LR chi2(3) 34.24
• 
  Prob gt chi2 0.0000
• Log likelihood -281.97993
  Pseudo R2 0.0572
• --------------------------------------------------
  --------------
• Variable Odds Ratio Pgtz 95
  Conf. Interval
• -------------------------------------------------
  --------------
• First-born status 1.635 0.039 1.025
  2.607
• Born to young father 1.294 0.484 .628
  2.668
• Male sex .407 0.000 .285
  .580
• --------------------------------------------------
  ------------------------------------

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Are young mothers responsible for the birth order
effect?

• Conditional (fixed-effects) logistic regression
  Number of obs 950
• 
  LR chi2(2) 37.35
• 
  Prob gt chi2 0.0000
• Log likelihood -280.42473
  Pseudo R2 0.0624
• --------------------------------------------------
  -----------------------------------
• Variable Odds Ratio
  Pgtz 95 Conf. Interval
• -------------------------------------------------
  -----------------------------------
• Born to young mother 2.031 0.001 1.326
  3.110
• Male sex .412 0.000 .289
  .586
• --------------------------------------------------
  -----------------------------------

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Maternal Age at Persons Birth and Odds to Become
a Centenarian
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Birth order effect explainedBeing born to young
mother!

• Conditional (fixed-effects) logistic regression
  Number of obs 950
• 
  LR chi2(3) 39.05
• 
  Prob gt chi2 0.0000
• Log likelihood -279.57165
  Pseudo R2 0.0653
• --------------------------------------------------
  -----------------------------------
• Variable Odds Ratio Pgtz
  95 Conf. Interval
• -------------------------------------------------
  -----------------------------------
• First-born status 1.360 0.189 .859
  2.153
• Born to young mother 1.760 0.021 1.089
  2.846
• Male sex .407 0.000 .285
  .580
• --------------------------------------------------
  ------------------------------------

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Even at age 75 it still helps to be born to young
mother (age lt25)(odds 1.9)

• Conditional (fixed-effects) logistic regression
  Number of obs 557
• 
  LR chi2(2) 21.31
• 
  Prob gt chi2 0.0000
• Log likelihood -185.08639
  Pseudo R2 0.0544
• --------------------------------------------------
  --------------------------------
• Variable Odds Ratio Pgtz
  95 Conf. Interval
• -------------------------------------------------
  --------------------------------
• Born to young mother 1.869 0.012 1.145
  3.051
• Male sex .461 0.000 .307
  .690
• --------------------------------------------------
  --------------------------------

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Back to a broader comparison of centenarian and
non-centenarian families
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Case-Control Study of Early-Life Conditions and
Exceptional Longevity
Cases - 382 households where centenarians (born
in 1890-1899) were raised (from centenarian
records linked to 1900 census) Controls 1
random sample of households with children below
age 10 enumerated by 1900 census (from Integrated
Public Use Microdata Sample, IPUMS
http//www.ipums.umn.edu/usa/index.html)
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Childhood Residence and Survival to Age 100Odds
for household to be in a centenarian group

• A New England and Middle Atlantic (reference
  group)
• B Mountain West and Pacific West
• C Southeast and Southwest
• D North Central

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Household Property Status During Childhood and
Survival to Age 100 Odds for household to be in
a centenarian group

• A Rented House
• B Owned House
• C Rented Farm
• D Owned farm
• (reference group)

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Paternal Immigration Status and Survival to Age
100 Odds for household to be in a centenarian
group

• A Father immigrated
• B Father native-born
• (reference group)

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No Association was Found (so far) Between Chances
to Become a Centenarian and

• Paternal literacy
• Child mortality of siblings

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Month of Birth Predicts the US Life Expectancy at
Age 80 Computed using the Social Security
Administration data
Source Gavrilova, N.S., Gavrilov, L.A. Search
for Predictors of Exceptional Human Longevity.
In Living to 100 and Beyond Monograph. The
Society of Actuaries, Schaumburg, Illinois, USA,
2005, pp. 1-49.
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Seasonality (month-of-birth effects) for
US life expectancy
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Within-Family Study of Month-of-Birth Effects on
Exceptional Longevity
Cases - Centenarians born in 1890-1893 Controls
Their own siblings Method Conditional logistic
regression Advantage Allows researchers to
eliminate confounding effects of between-family
variation
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Month of Birth and the Likelihood
to Become a Centenarian
Method Conditional logistic regression for odds
to become a centenarian, using siblings as
within-family control. 921 observations
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Month of Birth and the Likelihood
to Become a Centenarian
for Adult Siblings (20 years)
Method Conditional logistic regression for odds
to become a centenarian, using siblings as
within-family control. 787 observations
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Conclusions

• The shortest conclusion was suggested in the
  title of the New York Times article about our
  previous related study

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Conclusions

• The chances of exceptional longevity are
  strongly modulated by such characteristics of
  person's childhood as
• Mother's age at person's birth
• Month of birth
• Place of birth and some other characteristics of
  parental family
• Most important, these findings indicate that
  a larger research project on early-life
  determinants of exceptional human longevity is
  likely to produce more new results, very
  important for population studies

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Acknowledgments

• This study was made possible thanks to
• generous support from the National Institute on
  Aging and the Society of Actuaries

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For 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/

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• Objectives
• 1. To verify claims of exceptional longevity
  (living to 100) in the United Stated by checking
  the accuracy of birth dates through the early US
  Censuses (1900, 1910, 1920).
• 2. To collect information on early-life
  experiences of the future centenarians, and
  characteristics of the families where they were
  raised, using the early US Censuses (1900, 1910,
  1920), and family reconstitution data.
• 3. To test a number of hypotheses on possible
  links between early-life experiences in childhood
  and subsequent chances of exceptional longevity
• Findings
• 1. Claims of exceptional longevity have proved to
  be surprisingly trustworthy, if they are taken
  from genealogical records pre-selected for their
  good quality.
• 2. The following childhood conditions are linked
  to a subsequent survival to 100 years childhood
  farm background, childhood residence in Western
  States of the US, first birth order (explained
  through young mothers' age at person's birth),
  and the month of birth.
• The study supports the idea that early-life
  experiences in childhood may have long-lasting
  effects on exceptional survival in later life.

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• Objectives
• 1. To verify claims of exceptional longevity
  (living to 100) in the United Stated by checking
  the accuracy of birth dates through the early US
  Censuses (1900, 1910, 1920).
• 2. To collect information on early-life
  experiences of the future centenarians, and
  characteristics of the families where they were
  raised, using the early US Censuses (1900, 1910,
  1920), and family reconstitution data.
• 3. To test a number of hypotheses on possible
  links between early-life experiences in childhood
  and subsequent chances of exceptional longevity

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• Findings
• 1. Claims of exceptional longevity have proved to
  be surprisingly trustworthy, if they are taken
  from genealogical records pre-selected for their
  good quality.
• 2. The following childhood conditions are linked
  to a subsequent survival to 100 years childhood
  farm background, childhood residence in Western
  States of the US, first birth order (explained
  through young mothers' age at person's birth),
  and the month of birth.
• The study supports the idea that early-life
  experiences in childhood may have long-lasting
  effects on exceptional survival in later life.