O'Reilly logo

The Biostatistics of Aging: From Gompertzian Mortality to an Index of Aging-Relatedness by Gilberto Levy, Bruce Levin

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

5DISCUSSION: IMPLICATIONS

The causation framework and the method proposed here have widespread potential implications. In this chapter, we discuss the following topics from the perspective of our causation model and the index of aging-relatedness: the meaning of the Gompertz parameter (Section 5.1), age as a risk factor for disease (Section 5.2), the question of whether aging-related diseases are an integral part of aging (Section 5.3), biological versus chronological aging (Section 5.4), and the public health notions of compression of morbidity and mortality (Section 5.5). Finally, in Section 5.6, we draw a current picture of aging that emerges from this work.

5.1 THE MEANING OF THE GOMPERTZ PARAMETER

Our work provides a theoretical basis based on evolutionary biology and statistical theory for a Gompertz pattern of mortality in human populations, but it does so by eventually considering the Gompertz distribution as one of two components of a mixture distribution. That the already very good fit by the Gompertz (or the Weibull) model to the mortality data analyzed in Section 4.5, as judged by visual inspection, was substantially improved by the mixture model suggests it provides a more fundamental description of human mortality. This is arguably so even though some improvement over the Gompertz fit would follow merely from the increased flexibility afforded by the greater number of parameters in the mixture model. We note that, given the role played by the extreme dependence ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required