The scope and emphasis of a public health program are necessarily influenced by the changing characteristics of the population it serves. The rate of population growth affects long-range planning of community health and medical facilities. Alterations in age composition, internal migration of racial or industrial groups, changes in population density and urban-rural movement require current adaptation of the health program to solve the new problems thus created.
Among the various characteristics of recent population trends, aging of the population is one of the most fundamental in its bearing on national health. The social and economic effects of an aging population have long been recognized. Dr. Louis I. Dublin appraised the problem of old age in some detail in 1926, when the provision of economic security for the aged was the dominant theme of contemporary discussion. 1 The passage of the Social Security Act in 1935 represented the fruits of the efforts of this early period.
Adjustment of national policy with respect to the health problems associated with aging of the population has been slower in development. Under the terms of the Social Security Act, a limited expansion of activities designed to promote the health of older adults—control of cancer and pneumonia, and industrial hygiene services—has been made This paper was presented at the Eighteenth Annual Conference of the Milbank Memorial Fund, April 2–3, 1940. The Milbank Quarterly, Vol. 83, No. 4, 2005 (pp. 569–608)
c 2005 Milbank Memorial Fund. Published by Blackwell Publishing. Reprinted from The Milbank Memorial Fund Quarterly, Vol. 18, No. 4, 1940 (pp. 359–92). Style and usage are unchanged. possible in the cooperating States. However, the Act makes no provision for the solution of such fundamental problems as invalidity insurance and medical care of the aged. During the past five years, the health aspects of old age have received increasing attention in the discussions of public health administrators.
It therefore seems appropriate to resurvey this general problem, and to consider, in particular, the nature of future trends in mortality, morbidity, and the receipt of medical care which may be expected solely as a result of changing age structure of the population. The Effect on the Death Rate The effect of a declining proportion of children and an increasing proportion of “elders” on the future trend of the death rate may be readily predicated from the characteristics of age variation in mortality, which are generally familiar.
The period of infancy is characterized by a large proportion of fatally terminating illnesses. Following the high mortality of the first year, the death rate declines rapidly in the succeeding years of early childhood, and the rate among children 5 to 14 years of age is lower than in any period of life. The age curve of mortality remains at a relatively low level in youth and the young adult ages. During the period of middle age, a marked upward trend in the death rate becomes apparent, and the increase thereafter is progressive.
The sharp downward trend in the death rate following infancy and the rapid rise which occurs during middle and old age are the most pronounced characteristics of age variation in mortality. The mortality rate in infancy and early childhood has shown a marked reduction in the present century, while the rate at the advanced ages has remained practically unchanged. Thus, the death rate at the older ages has shown an increasing relative excess over the rate in the early years of life. Furthermore, aging of the population has increased the number of older persons exposed to the chance of death.
Deaths of persons 45 years of age and over constituted over two-thirds of all deaths in this country in 1935; in the Registration States of 1900, the proportion was approximately two-fifths. It thus results that the diseases which at present are the leading causes of death in the population of all ages are largely those characteristic of middle and old age. Diseases of the heart, cerebral hemorrhage, nephritis, cancer, and diabetes accounted for 65 per cent of the deaths among persons 45 years of age and over, and for 44 per cent of the total deaths