SHIRO HORIUCHI

Aging and Mortality

We study relationships among aging, morbidity and mortality through quantitative analysis of demographic and epidemiologic data. We have developed an approach that uses the life-table aging rate (LAR), which is the rate of relative mortality increase with age (technically, the derivative with respect to age of the logarithm of the age-specific deathrate). LAR patterns differ among major causes of death, suggesting different types of relationships between senescence and disease development. We plan to model those relationships. LAR patterns are generally stable, in spite of significant changes and variations in mortality levels. However, patterns for some diseases change over time, differ between males and females, or vary among countries with different epidemiologic profiles. We are investigating reasons for the variations.

Population Dynamics

We study the growth and compositional changes of human populations in which fertility, mortality and migration rates continue to change. We have developed and modified several statistical methods for decomposing population growth and age distribution changes. An application has provided a quantitative explanation for the puzzling combination of the positive actual and negative intrinsic growth rates in many industrialized countries. Publications