Health and disease in the United States.

Abstract

The characterization of the overall health status of a population or of an individual is not a simple task. Many factors must be considered. Factors relating to mortality, such as life expectancy, mortality rates, both total and cause specific, infant mortality, and maternal mortality, are frequently used to assess the health of the people in an area. These measures are relatively easy to obtain and are available for small geographic areas and often for subgroups of the population. In addition, these measures are frequently available for other countries and, although there are definitional differences, international comparisons can be helpful. Finally, the impact of medical intervention on these measures is generally very direct, i.e. mortality rates should go down and life expectancy should increase-both desirable objec­ tives-with necessary and appropriate medical treatment. Many other measures of health status have been used to characterize a population. The most common are measures of illness, i.e. the prevalence and incidence of specific diseases and the impact of these diseases as mea­ sured by disability (8). In the past much of the information of this type was based on research conducted in hospitals at medical schools. However, because only about 10% of the population in any year is hospitalized and ofthis group only 10% is in teaching hospitals, much ofthe health informa­ tion from examinations was based on only 1 % of the population. In 1960 the National Center for Health Statistics (NCHS) initiated a major effort to improve the representativeness of health data by forming the National Health Examination Survey (now called Health and Nutrition Examination