Predictors of Exceptional Human Longevity Dr Leonid A

Predictors of Exceptional Human Longevity Dr. Leonid A. Gavrilov, Ph. D. Dr. Natalia S. Gavrilova, Ph. D. Center on Aging NORC and The University of Chicago, Illinois, USA 2006 Chicago Actuarial Association Workshop

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) 2006 Chicago Actuarial Association Workshop

Revolution in Information Technology What does it mean for longevity studies? Over 75 millions of computerized genealogical records are available online now! 2006 Chicago Actuarial Association Workshop

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 2006 Chicago Actuarial Association Workshop

Computerized Genealogies as a Resource for Longevity Studies n 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) n Cons: Uncertain data quality Uncertain validity and generalizability 2006 Chicago Actuarial Association Workshop

For longevity studies the genealogies with detailed birth dates and death dates for longlived 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 2006 Chicago Actuarial Association Workshop

2006 Chicago Actuarial Association Workshop

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 2006 Chicago Actuarial Association Workshop

Steps of Centenarian Age Verification 1. 2. 3. Internal consistency checks of dates Verification of death dates – linkage to the Social Security Administration Death Master File (DMF) Verification of birth dates – linkage to early Federal censuses (1900, 1910, 1920, 1930) 2006 Chicago Actuarial Association Workshop

A typical image of ‘centenarian’ family in 1900 census 2006 Chicago Actuarial Association Workshop

Results of Centenarian Age Verification 1001 records 990 records used for further consistency checks 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 2006 Chicago Actuarial Association Workshop

Conclusions of the Age Verification Study n Death dates of centenarians recorded in genealogies always require verification because of strong outliers (1. 3%, misprints) n Birth dates of centenarians recorded in genealogies are sufficiently accurate - 92% are correct; for the remaining 8% only one-year disagreements n Quality of genealogical data is good enough if these data are pre-selected for high data quality 2006 Chicago Actuarial Association Workshop

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 2006 Chicago Actuarial Association Workshop

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. 2006 Chicago Actuarial Association Workshop

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 betweenfamily variation. 2006 Chicago Actuarial Association Workshop

First-born siblings are more likely to become centenarians (odds = 1. 8) Conditional (fixed-effects) logistic regression Log likelihood = -282. 22348 Number of obs LR chi 2(2) Prob > chi 2 Pseudo R 2 = = 950 33. 75 0. 0000 0. 0564 -----------------------------------Variable Odds Ratio P>|z| [95% Conf. Interval] -------+---------------------------- First-born status Male sex 1. 772 0. 006 1. 180 2. 663 . 404 0. 000 . 284 . 576 ----------------------------------------- 2006 Chicago Actuarial Association Workshop

Can the birth-order effect be a result of selective child mortality, thus not applicable to adults? Approach: n To compare centenarians with those siblings only who survived to adulthood (age 20) 2006 Chicago Actuarial Association Workshop

First-born adult siblings (20+years) are more likely to become centenarians (odds = 1. 95) Conditional (fixed-effects) logistic regression Log likelihood = -247. 93753 Number of obs LR chi 2(2) Prob > chi 2 Pseudo R 2 = = 797 27. 54 0. 0000 0. 0526 -----------------------------------------Variable | Odds Ratio P>|z| [95% Conf. Interval] -------+---------------------------------- First-born status | 1. 949 0. 003 1. 261 3. 010 Male sex | . 458 0. 000 . 318 . 658 ----------------------------------------- 2006 Chicago Actuarial Association Workshop

Even at age 75 it still helps to be a first-born child (odds = 1. 7) Conditional (fixed-effects) logistic regression Log likelihood = -186. 22869 Number of obs LR chi 2(2) Prob > chi 2 Pseudo R 2 = = 557 19. 03 0. 0001 0. 0486 --------------------------------Variable Odds Ratio P>|z| [95% Conf. Interval] -------+------------------------- First-born status 1. 659 0. 040 1. 022 2. 693 Male sex . 459 0. 000 . 306 . 687 -------------------------------- 2006 Chicago Actuarial Association Workshop

Are young fathers responsible for birth order effect? Conditional (fixed-effects) logistic regression Log likelihood = -284. 04284 Number of obs LR chi 2(2) Prob > chi 2 Pseudo R 2 = = 950 30. 11 0. 0000 0. 0503 -------------------------------------Variable Odds Ratio P>|z| [95% Conf. Interval] -------+------------------------------- Born to young father Male sex 1. 856 0. 056 . 985 3. 496 . 415 0. 000 . 291 . 590 -------------------------------------- 2006 Chicago Actuarial Association Workshop

Birth order is more important than paternal age for chances to become a centenarian Conditional (fixed-effects) logistic regression Log likelihood = -281. 97993 Number of obs LR chi 2(3) Prob > chi 2 Pseudo R 2 = = 950 34. 24 0. 0000 0. 0572 --------------------------------Variable Odds Ratio P>|z| [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 ------------------------------------------- 2006 Chicago Actuarial Association Workshop

Are young mothers responsible for the birth order effect? Conditional (fixed-effects) logistic regression Log likelihood = -280. 42473 Number of obs LR chi 2(2) Prob > chi 2 Pseudo R 2 = = 950 37. 35 0. 0000 0. 0624 ------------------------------------------Variable Odds Ratio P>|z| [95% Conf. Interval] -------+------------------------------------ Born to young mother 2. 031 0. 001 1. 326 3. 110 Male sex . 412 0. 000 . 289 . 586 ------------------------------------------- 2006 Chicago Actuarial Association Workshop

Birth order effect explained: Being born to young mother! Conditional (fixed-effects) logistic regression Log likelihood = -279. 57165 Number of obs LR chi 2(3) Prob > chi 2 Pseudo R 2 = = 950 39. 05 0. 0000 0. 0653 ------------------------------------------- Variable Odds Ratio P>|z| [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 ------------------------------------------- 2006 Chicago Actuarial Association Workshop

Even at age 75 it still helps to be born to young mother (age <25) (odds = 1. 9) Conditional (fixed-effects) logistic regression Log likelihood = -185. 08639 Number of obs LR chi 2(2) Prob > chi 2 Pseudo R 2 = = 557 21. 31 0. 0000 0. 0544 ----------------------------------------- Variable Odds Ratio P>|z| [95% Conf. Interval] -------+---------------------------------- Born to young mother 1. 869 0. 012 1. 145 3. 051 Male sex . 461 0. 000 . 307 . 690 ----------------------------------------- 2006 Chicago Actuarial Association Workshop

Back to a broader comparison of ‘centenarian’ and ‘non-centenarian’ families 2006 Chicago Actuarial Association Workshop

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) 2006 Chicago Actuarial Association Workshop

Childhood Residence and Survival to Age 100 Odds for household to be in a ‘centenarian’ group A – New England Middle Atlantic (reference group) B – Mountain West and Pacific West C – Southeast and Southwest D – North Central 2006 Chicago Actuarial Association Workshop

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) 2006 Chicago Actuarial Association Workshop

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) 2006 Chicago Actuarial Association Workshop

No Association was Found (so far) Between Chances to Become a Centenarian and n n Paternal literacy Child mortality of siblings 2006 Chicago Actuarial Association Workshop

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. 2006 Chicago Actuarial Association Workshop

Seasonality (month-of-birth effects) for US life expectancy 2006 Chicago Actuarial Association Workshop

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 betweenfamily variation 2006 Chicago Actuarial Association Workshop

Month of Birth and the Likelihood to Become a Centenarian Method: Conditional logistic regression for odds to become a centenarian, using siblings as withinfamily control. 921 observations 2006 Chicago Actuarial Association Workshop

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 withinfamily control. 787 observations 2006 Chicago Actuarial Association Workshop

Conclusions n The shortest conclusion was suggested in the title of the New York Times article about this study 2006 Chicago Actuarial Association Workshop

2006 Chicago Actuarial Association Workshop

Conclusions n n n The accuracy of 'longevity risk' estimates can be greatly improved by using such 'trivial' information about 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 subsequent large-scale research project on early -life determinants of human longevity is likely to produce more new results, very important for actuarial science and practice 2006 Chicago Actuarial Association Workshop

Acknowledgments This study was made possible thanks to: generous support from the Society of Actuaries and the National Institute on Aging n 2006 Chicago Actuarial Association Workshop

For More Information and Updates Please Visit Our Scientific and Educational Website on Human Longevity: n http: //longevity-science. org And Please Post Your Comments at our Scientific Discussion Blog: n http: //longevity-science. blogspot. com/ 2006 Chicago Actuarial Association Workshop