Summary measures of population health: methods for calculating healthy life expectancy.

This report is one of several appearing as Healthy People Statistical Notes that evaluate methodological issues pertaining to summary measures. Summary measures of population health are statistics that combine mortality and morbidity to represent overall population health in a single number--in this report, health expectancy measures. This report presents a comprehensive discussion of the methods for calculation and methodologic issues related to the interpretation of healthy life expectancy. These measures combine both mortality and morbidity using an abridged life-table procedure. Data from the National Center for Health Statistics and other sources will be used to illustrate the calculation of the statistics and the associated statistical tests.

Summary measures of population health: addressing the first goal of healthy people 2010, improving health expectancy.

This report is one of several Healthy People Statistical Notes that evaluate methodological issues pertaining to summary measures - statistics that combine mortality and morbidity data to represent overall population health in a single number. This report evaluates the consequences of changes in the components of health expectancy measures (i.e., mortality or morbidity) on the overall measure. Any activity limitation is used as a morbidity measure. Simulations are used to evaluate the impacts of reducing 1995 age-specific mortality or activity limitation rates by 5, 10, 25, and 50 percent at all ages. Then it is limited to ages under 25 years, 25 -64 years, and over 64 years. The impact of completely eliminating mortality or activity limitation for the younger age groups is also examined. In general, reducing morbidity rates results in greater changes than the same percent reduction in death rates. The same proportional reduction in age-specific rates for either mortality or morbidity has a greater impact if it occurs at older ages. Reducing mortality results in a greater change in life expectancy than in health expectancy and a decline in the proportion of life lived in healthy states. Reducing morbidity increases both health expectancy and the proportion of life lived in healthy states. Simultaneous reductions in mortality and morbidity have additive effects on health expectancy.