The Demography of Aging

Abstract

Demography is the study of changes in the size, diversity, distribution and composition of human populations over time. The world’s age composition has changed dramatically and these changes continue. The percentage of individuals ≥65 years of age will double from 7 to 14 %, rising from 506 million in 2008 to 1.4 billion by 2040, with the largest increases in developing countries. It is important to note that the older population is getting older, with the largest increases in those ≥80 years of age. Life expectancy at age 65 has increased. In 2003, the average 65-year old woman in the United States was expected to live an additional 19.6 years, and a man, an additional 16.8 years. The older population is mostly female, especially in developed nations. Cardiovascular disease is the major cause of death worldwide. Disability in older adults is declining, though these trends may not continue given the exponential growth of the oldest old population. These demographic changes will profoundly impact public health. Cross-national research must address this unprecedented growth, specifically longitudinal studies to identify links between health, disability, economic status, work and family structure; to establish mechanisms to harmonize and standardize data collection internationally; and to develop multidisciplinary research designs to address issues impacted by population aging.