Discussion of the Paper:

“IDL, the International Database on Longevity”Living to 100 Symposium

Society of Actuaries

Leonid A. Gavrilov, Ph.D.

Center on Aging NORC and University of Chicago

Chicago, Illinois, USA

Disclaimer

• This discussion may be incomplete because the discussed paper was received only at the Symposium

Why Supercentenarian Studies are so Important?

• Extreme cases are particularly informative for discriminating between competing theories

(Peter Kapitsa, physicist, Nobel prize winner)

• Extreme cases of longevity are particularly informative for discriminating between competing theories of aging and longevity

Historical Note

• Early studies starting with Gompertz (1825) himself suggested mortality deceleration and leveling-off at advanced ages

• Later studies by British researchers, Greenwood and Irwin (1939) suggested that mortality force becomes constant at extreme old ages

M. Greenwood, J. O. Irwin. BIOSTATISTICS OF SENILITY

Mortality at Advanced Ages

Source: Gavrilov L.A., Gavrilova N.S. The Biology of Life Span: A Quantitative Approach, NY: Harwood Academic Publisher, 1991

Constant failure rate at extreme old ages was also predicted by the

reliability theory of aging and longevity

• Gavrilov L.A., Gavrilova N.S. The Biology of Life Span: A Quantitative Approach, NY: Harwood Academic Publisher, 1991

• Gavrilov, L.A., Gavrilova, N.S. The reliability theory of aging and longevity. J. Theor. Biol. 213, 527-545, 2001.

Non-Gompertzian Mortality Kinetics of Four Invertebrate Species

Non-Gompertzian mortality kinetics of four invertebrate species: nematodes, Campanularia flexuosa, rotifers and shrimp.

Source: A. Economos. A non-Gompertzian paradigm for mortality kinetics of metazoan animals and failure kinetics of manufactured products. AGE, 1979, 2: 74-76.

Non-Gompertzian Mortality Kinetics of Three Rodent Species

Non-Gompertzian mortality kinetics of three rodent species: guinea pigs, rats and mice.

Source: A. Economos. A non-Gompertzian paradigm for mortality kinetics of metazoan animals and failure kinetics of manufactured products. AGE, 1979, 2: 74-76.

Non-Gompertzian Mortality Kinetics of Three Industrial Materials

Non-Gompertzian mortality kinetics of three industrial materials: steel, industrial relays and motor heat insulators.

Source: A. Economos. A non-Gompertzian paradigm for mortality kinetics of metazoan animals and failure kinetics of manufactured products. AGE, 1979, 2: 74-76.

Thus, the conclusion of the discussed paper:

“… Striking feature of these [supercentenarian] survival curves is the seemingly exponential decline in survival probabilities”

fits well with the earlier studies and theoretical predictions

(except that these earlier studies are not cited in the discussed paper)

Remaining questions and methodological concerns

• Where is the proof that the list of supercentenarians is indeed complete or age-ascertainment-bias free?

• Where are the data themselves? There are no data in the announced

www.supercentenarians.org

Specific question for discussion

“… this [supercentenarian] list is assumed to be age-ascertaintment-bias free (Kestenbaum and Fergusson, 2002…)

Questions for discussion: • Is this list really bias-free?• How do we know that it is unbiased?