The compression of morbidity

In this century we are progressing throughthree separate eras with dramatically different characteristics ofhealth and illness. We entered the century in an era of infectious disease, with tuberculosis the number one killer of our population, and smallpox, diphtheria, tetanus, and other infectious illnesses extremely prevalent. A reduction in mortality from these diseases of over 99 per-cent (Fries and Crapo 1981; Cooper 1982) has led to the present era, where the major burdens of illness of the United States are the chronic diseases. Atherosclerosis and its complications, neoplasia, emphysema, diabetes, cirrhosis, and osteoarthritis have increased in prevalence even as the infectious illnesses which preceded them declined. It is one thesis of this discussion that this chronic disease era in its turn will slowly decline in significance, leaving a third era in which the major health problems of the United States will be directly related to the process of senescence, and where the aging process itself, independent of spe-cific disease, will constitute a major burden of illness for the United States. The ultimate constraint within which we must develop health policy for the future is, of course, the limit of life itself. Man is mortal, and the limits to what presently may be accomplished in decreasing mortality are set by the life span of our species. In the following discussion, we wil