Years of healthy life.

Increasing the span of healthy life for Americans is one of the three broad goals of Healthy People 2000 (1). The years of healthy life measure has been selected for monitoring progress toward this goal. The sources and methods used for calculating years of healthy life are described in this issue of Statistical Notes. Estimated years of healthy life measures for 1990 for the total U.S. population and for selected subgroups are presented and discussed. Historically, health has been measured primarily in terms of mortality—infant mortality, life expectancy, age-specific and disease-specific death rates—and morbidity—disability days and prevalence of chronic conditions. On the one hand, measures of mortality may understate the public health importance of conditions that result in proportionately more morbidity and disability. On the other hand, commonly used morbidity measures tend to focus on physical function and thus may underestimate social and mental dysfunction as well as satisfaction with health. In addition, these traditional indicators do not provide summary information on a population’s health status. A single measure that incorporates health-related quality of life and life expectancy gives a more comprehensive picture of the population’s health. Such a summary number would help in monitoring the Nation’s health, identifying health priorities, evaluating the effectiveness of interventions, and comparing the effectiveness of different interventions. Several approaches to the development of a comprehensive measure have been taken, including Disability Free Life Years (2,3), Healthy Life Expectancy (4,5), and Disability Adjusted Life Years (6). The years of healthy life (YHL) concept, however, has emerged as one of the more commonly used health status measures that include both mortality and morbidity. Years of healthy life can be sensitive to changes in health among the well and the ill.