Over thirty years ago when I first began to examine the
postulates of gerontology and human aging I did so from
a background in medicine, rheumatology, clinical epidemiology,
health outcomes research, and health policy, with
an emphasis on prevention and on outcomes of chronic
illness [6]. From this perspective, it seemed clear that much
diminished capacity could be postponed or even prevented
at the individual level and thus potentially at the population
level. It also seemed clear that overall national improvements
in health would likely require reduction in health
risks [7, 8]. Thus, the marked reduction in heart disease
mortality beginning in the nineteen-sixties was associated
with decreases in risk factors such as smoking and cholesterol
levels. These clearly affected both age-specific incidence
rates and mortality rates. Disease-associated morbidity from
heart disease now developed later in life and mortality also
was postponed. An evolving challenge was to develop risk
factor models on a population basis rather than a diseasespecific
one, since allocation of disability and other outcomes
to specific diseases is difficult and competing risks make
apportionment inaccurate as well.