1. Biodemography of Human Longevity: New Methodological Approaches Dr. Leonid A. Gavrilov, Ph.D. Dr. Natalia S. Gavrilova, Ph.D. Center on Aging NORC and The University of Chicago Chicago, Illinois, USA

2. General Approach To study “success stories” in long-term avoidance of fatal diseases (survival to 100 years) and factors correlated with this remarkable survival success

3. 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)

4. Revolution in Information Technology What does it mean for longevity studies? Over 75 millions of computerized genealogical records are available online now!

5. Online Data Resources Used in These Studies: Computerized genealogies Early U.S. censuses (1900, 1910, etc.) IPUMS (Integrated Public Use Microdata Series) – 1% censuses Social Security Administration Death Master File WWI civil draft registration cards

6. Approach 1: Using computerized genealogies

7. 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

8. 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

9. 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

11. 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

12. 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)

13. A typical image of ‘centenarian’ family in 1900 census

14. 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 difference between genealogy and census record was observed for birth year

15. Conclusions of the Age Verification Study Death dates of centenarians recorded in genealogies always require verification because of strong outliers (10- 20 years difference, 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

16. Study 1: Compare centenarians found in computerized genealogies with general population

17. Case-Control Study of Early-Life Conditions and Exceptional Longevity Cases - 382 ‘white’ households where centenarians (born in 1890-1899) were raised (from centenarian records linked to 1900 census) Controls – 1% random sample of ‘white’ 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 )

18. Statistical Approach: Logistic regression Dependent variable: Households with child-future centenarian (y=1) vs control households (y=0) Predictor variables: childhood residence, household property status, paternal immigration status, etc.

19. 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 Central

20. 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)

21. 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)

22. No Association was Found (so far) Between Chances to Become a Centenarian and Paternal literacy Child mortality of siblings

23. Limitations Reporting bias in genealogies People mentioned in genealogies may be not representative to the whole population: more fertile, longer-living (?), wealthier (?), more educated (?)

24. Study 2: Compare centenarians with their siblings (between-family study)

25. 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 + bx 2 + cz + d where x – birth order; z – family size; a,b,c,d – parameters of polynomial regression model

26. 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.

27. Study 3: Compare centenarians with their siblings (within-family study)

28. Within-Family Study of Exceptional Longevity Cases - 198 Centenarians born in U.S. in 1890-1893 Controls – Their own siblings Method: Conditional logistic regression Advantage: Allows researchers to eliminate confounding effects of between- family variation

29. Design of the Study

30. First-born siblings are more likely to become centenarians (odds = 1.8) Conditional (fixed-effects) logistic regression N=950, Prob > chi2=0.0000 VariableOdds ratio95% CIP-value First-born status 1.771.18-2.660.006 Male sex0.400.28-0.58<0.001

31. Birth Order and Odds to Become a Centenarian

32. 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)

33. First-born adult siblings (20+years) are more likely to become centenarians (odds = 1.95) Conditional (fixed-effects) logistic regression N=797, Prob > chi2=0.0000 VariableOdds ratio95% CIP-value First-born status 1.951.26-3.010.003 Male sex0.460.32-0.66<0.001

34. Are young fathers responsible for birth order effect? Conditional (fixed-effects) logistic regression N=950, Prob > chi2=0.0000 VariableOdds ratio95% CIP-value Born to young father 1.860.99-3.500.056 Male sex0.420.29-0.59<0.001

35. Birth order is more important than paternal age for chances to become a centenarian Conditional (fixed-effects) logistic regression N=950, Prob > chi2=0.0000 VariableOdds ratio95% CIP-value First-born status 1.641.03-2.610.039 Born to young father 1.290.63-2.670.484 Male sex0.410.29-0.58<0.001

36. Are young mothers responsible for the birth order effect? Conditional (fixed-effects) logistic regression N=950, Prob > chi2=0.0000 VariableOdds ratio95% CIP-value Born to young mother 2.031.33-3.110.001 Male sex0.410.29-0.59<0.001

37. Maternal Age at Person’s Birth and Odds to Become a Centenarian

38. Birth order effect explained: Being born to young mother! Conditional (fixed-effects) logistic regression N=950, Prob > chi2=0.0000 VariableOdds ratio95% CIP-value First-born status 1.360.86-2.150.189 Born to young mother 1.761.09-2.850.021 Male sex0.410.29-0.58<0.001

39. Even at age 75 it still helps to be born to young mother (age <25) (odds = 1.9) Conditional (fixed-effects) logistic regression N=557, Prob > chi2=0.0000 VariableOdds ratio95% CIP-value Born to young mother 1.861.15-3.050.012 Male sex0.460.31-0.69<0.001

40. Conclusions Centenarians are more likely to be first-born The effect of first-born status is driven mostly by young maternal age (<25) at person’s birth Being born to young mother is an important predictor of human longevity even at age 75

41. Approach 2: Using Social Security Administration Death Master File

42. What 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- 2003 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

44. Month-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

45. 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.

46. Seasonality (month-of-birth effects) for US life expectancy

47. Approach 3: Using Civil Draft Registration Cards

48. Physical Characteristics at Young Age and Survival to 100 A study of height and build of centenarians when they were young using WWI civil draft registration cards

49. WWI Civilian Draft Registration In 1917 and 1918, approximately 24 million men born between 1873 and 1900 completed draft registration cards. President Wilson proposed the American draft and characterized it as necessary to make "shirkers" play their part in the war. This argument won over key swing votes in Congress.

50. Information Available in the Draft Registration Card age, date of birth, race, citizenship permanent home address occupation, employer's name height (3 categories), build (3 categories), eye color, hair color, disability

51. Draft Registration Card: An Example

52. Data Sources 1. Social Security Administration Death Master File 2. WWI civil draft registration cards (completed for almost 100 percent men born between 1873 and 1900)

53. Study Design Cases: men centenarians born in 1887 (randomly selected from the SSA Death Master File) and linked to the WWI civil draft records. Out of 120 selected men, 19 were not eligible for draft. The linkage success for remaining 101 records was 75% (76 records) Controls: men matched on birth year, race and county of WWI civil draft registration

54. Height and Survival to 100

55. Body Build and Survival to 100

56. Results of multivariate study VariableORP-value Tall and medium height vs short height 1.980.308 Slender and medium build vs stout build 9.96*0.032 Qualified jobs vs unqualified 1.570.300 Married vs unmarried1.020.958 Natural born vs immigr. 1.120.782

57. Conclusion The study of height and build among men born in 1887 suggests that rapid growth and overweight at young adult age (30 years) might be harmful for attaining longevity

58. General Conclusion The shortest conclusion was suggested in the title of the New York Times article about our previous related study

60. 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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