Search for Predictors of Exceptional Human Longevity:

Using Computerized Genealogies and Internet Resources for Human Longevity Studies

Natalia S. Gavrilova, Ph.D.Leonid A. Gavrilov, Ph.D.

Center on Aging

NORC and University of Chicago Chicago, Illinois, USA

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 Jeanne Calment

(1875-1997)

Revolution in Information Technology

What does it mean for longevity studies?

Over 75 millions of computerized

genealogical records are available online now!

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

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

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

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)

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

Indexes of all persons enumerated by 1930 federal census and census page images are provided by Ancestry.com

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

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

Birth Order and Chances to Become a Centenarian

Cases - centenarians born between 1890 and 1899

Controls – their siblings born in the same time window

Model:

where x – birth order; z – family size; a, b, c, d – parameters of polynomial regression model

Birth Order and Odds to Become a Centenarian

Birth order

1 2 3 4 5 6 7 8 9 10

Od

ds t

o b

eco

me a

cen

ten

ari

an

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

FemalesMales

Case-Control Study of Early-Life Conditions and Exceptional Longevity

Cases - households where centenarians 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)

Childhood Residence and Survival to Age 100

Odds 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 Central0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

A B C D

MalesFemales

Household Property Status During Childhood and Survival to Age 100

Odds for household to be in a ‘centenarian’ group

A – Rented House (reference group)

B – Owned House

C – Rented Farm

D – Owned farm0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

A B C D

MalesFemales

Paternal Immigration Status and Survival to Age 100

Odds for household to be in a ‘centenarian’ group

A – Father immigrated (reference group)

B – Father native-born

0

0.5

1

1.5

2

2.5

3

A B

MalesFemales

Age of Father at Census Date and Survival to Age 100

Odds for household to be in a ‘centenarian’ group

A – Father <50 years (reference group)

B – Father 50+ years

00.10.20.30.40.50.60.70.80.9

1

A B

Males

Females

Mortality of Siblings and Survival to Age 100

Odds for household to be in a ‘centenarian’ group

A – Less than 70% of siblings survived (reference group)

B – More than 70% of siblings survived (reference group)

0.5

0.7

0.9

1.1

1.3

1.5

1.7

1.9

A B

MalesFemales

Gender-Specific Factors Affecting Survival to Age 100

Males - father’s immigrant status decreases chances to become a centenarian

Females – father older than 50 years in household and poor survival of siblings (less than 70%) decreases chances to become a centenarian

Further Extension of this Study: Using Data from the Social Security

Death Master File (DMF)

(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.

Month of Birth

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

life

exp

ecta

ncy a

t ag

e 8

0,

years

7.6

7.7

7.8

7.9

1885 Birth Cohort1891 Birth Cohort

Conclusions• Computerized genealogies is a valuable resource

for longevity studies, which could and should be used more extensively

• Early-life conditions are important predictors of survival to extreme ages as well as of old-age mortality

• Centenarians are more likely to have lower birth orders (women in particular)

• Late-life mortality deceleration appears to be not that strong - cohort mortality at advanced ages continues to grow up to age 105 years

Acknowledgments

This study was made possible thanks to:

generous support from the

Society of Actuaries

stimulating working environment at the Center on Aging, NORC/University of

Chicago

For More Information and Updates Please Visit Our

Scientific and Educational Website

on Human Longevity:

• http://longevity-science.org