creation acknowledges the ferment of new approaches to health care.
The public has asked for more active involvement in consumer choices and for more accurate information on which to base such choices. In response, a self-care movement in health has developed, which now represents a considerable social force. At its best, this movement encourages critical consumption of medical services and increased autonomy from professional dominance. At its worst, the self-care movement takes an adversary stance and would replace professional medical treatment with idiosyncratic folk remedies. Still, the growth of these movements indicates discontent with the prevailing medical orthodoxy.
Recent changes in personal lifestyles have been even more significant. Joggers organize footraces in which tens of thousands compete, and cocktail party conversations concern the number of miles run per week. The number of militant antismokers has grown, and the nonbelievers are being packed into smaller and smaller spaces in the back of the airplane. Such spontaneous social changes are very likely to have constructive effects on health, and we applaud them, but the point is that the phenomenon itself represents a profound changing of the public consciousness.
Within professional medicine, new themes are evident. There is an increased interest in long-term patient outcome as a goal and less interest in correcting the trivial laboratory abnormality that does not materially affect the patient. Benefit-cost studies are sometimes advocated as a solution to the astronomical increases in the cost of medical care. Many observers have pointed out that orthodox medical approaches have reached the area of diminishing returns. The quality of life, rather than its duration, has received increasing emphasis.
Both psychologists and physicians have recently described strong relationships between psychological factors and health, and theories explaining such relationships have been developed that emphasize life crises, helplessness, loss of personal autonomy, depression, and other psychological factors. Correction of some psychological problems, it is implied, will improve health, and indeed the circumstantial evidence that this may be true is quite convincing. Again these approaches are outside the orthodoxy of the medical model.
Two new research areas have recently been emphasized—chronic disease and human aging. Increasingly, researchers recognize the central roles that aging and chronic disease play in our current health problems. The study of aging and chronic disease is oriented toward long-term outcomes, is interdisciplinary, requires preventive strategies, seeks to demonstrate the relevance of psychological factors, and uses lifestyle modification as a major tactic. The student of aging and the student of the diseases of the aged now have a unique opportunity to harmonize the incomplete old orthodoxy and the emerging new themes.
A New Syllogism
Using new knowledge of human aging and of chronic disease, we attempt here to provide a model that harmonizes these competing and chaotic themes, one that points toward new strategies of research and of health attainment. Our theoretical structure allows predictions to be made, and the predictions are strikingly different from those traditionally expected.
These curves are correct. They converge at the same maximum age, thereby demonstrating that the maximum age of survival has been fixed over this period of observation.
Figure 1 shows the actual data. Quite … startling conclusions follow from these data. The number of extremely old persons will not increase. The percentage of a typical life spent in dependency will decrease. The period of adult vigor will be prolonged. The need for intensive medical care will decrease. The cost of medical care will decrease, and the quality of life, in a near disease-free society, will be much improved.
Adult life may be conveniently divided into two periods, although the dividing line is indistinct. First, there is a period of independence and vigor. Second, for those not dying suddenly or prematurely, there is a period of dependence, diminished capacity, and often lingering disease. This period of infirmity is the problem; it is feared, by many, more than death itself. The new syllogism does not offer hope for the indefinite prolongation of life expectancy, but it does point to a prolongation of vitality and a decrease in the period of diminished capacity.
Figure 1 Human Survival Curves for 1900, 1920, 1940, 1960, and 1980
Source: U.S. Bureau of Health Statistics.
There are two premises to the syllogism; if they are accepted, then it follows that there will be a reversal of the present trend toward increasing infirmity of our population and increased costs of support of dependency…. The first premise is almost certain; the second is very probable. If, after careful evaluation of the supporting data, one accepts the premises of this syllogism, then one must accept the conclusion and the implications of the conclusion.
Some Questions of Semantics
Nuances of meaning may mask the substance of a subject, and slight changes in emphasis may allow a new perspective to be better appreciated. There are problems with several of the terms often used to describe health, medical care, and aging. Among these are cure, prevention, chronic, premature death, and natural death. We will use these terms in slightly different senses than is usual.
Cure is a term with application to few disease processes other than infections. The major diseases of our time are not likely to be cured, and we have tried to avoid this term. Prevention is better but is unfortunately vague; this term, as we shall see, is sometimes misleading. We prefer the term postponement with regard to the chronic diseases of human aging, since prevention in the literal sense is difficult or impossible. Chronic is a term usually used to denote illnesses that last for a long period of time. It serves as a general but imprecise way of distinguishing the diseases that may be susceptible to cure (such as smallpox) from those better approached by postponement (as with emphysema). Regrettably, this important distinction cannot be based solely on the duration of the illness, since some diseases that last a long time both are not chronic conditions and might eventually be treatable for cure (such as rheumatoid arthritis and ulcerative colitis). We limit our use of the term chronic to those conditions that are nearly universal processes, that begin early in adult life, that represent insidious loss of organ function, and that are irreversible. Such diseases (atherosclerosis, emphysema, cancer, diabetes, osteoarthritis, cirrhosis) now dominate human illness in developed countries. We have defined premature death simply as death that occurs before it must, and we have used natural death to describe those deaths that occur at the end of the natural life span of the individual….
A New Syllogism
1 The human life span is fixed.
2 The age at first infirmity will increase.
3 Therefore the duration of infirmity will decrease.
The Rectangular Curve
Survival curves for animals show a similar pattern of rectangularization with domestication or better care. Old age in wild animals is very rare, as it probably was for prehistoric man living in a dangerous environment. In uncivilized environments, accidental deaths and violent deaths account for a greater proportion of deaths than the biologically determined life-span limit. For the great majority of wild animal species, there is a very high neonatal mortality, followed by an adult mortality rate that is almost as high and is nearly independent of age. In such environments, death occurs mostly as a result of accidents and attacks by predators. One day
