DISABILITY AS A PUBLIC-HEALTH OUTCOME IN THE AGING POPULATION

Improvements in life expectancy in the twentieth century have resulted from major declines in mortality at younger ages, but it is less well recognized that mortality declines at older ages have also played a s ubstantial role in prolonging expectation of life. A person reaching a ge 65 in 1900 could expect to live an additional 11.9 years. Life expe ctancy at age 65 rose to 14.4 years by 1960 and then increased by abou t three years in the next three decades, reaching 17.5 years in 1992 ( 56, 70). As a greater proportion of the population survives to very ol d ages, the public health impact of the burden of disease and disabili ty and related utilization of medical care and need for supportive and long-term care has become an important concern. In particular, the ab ility of the older person to function independently in the community i s a critically important public health issue. A growing body of resear ch in the last decade has addressed the measurement of disability, fac tors related to its onset, consequences of disability, and the potenti al for preventive interventions. This article summarizes the state of the art in these areas and discusses their public health relevance.