Public Health: I. Determinants
Public Health: I. Determinants
The current preoccupation with medical science and its application as the primary determinant of health derives largely from the enormously successful experience with applying microbiology in the battle against ill health. Identification of specific microorganisms as agents of epidemic communicable diseases, and means of controlling them, aroused expectations of finding "magic bullets" for most of humanity's ills. Further discoveries, such as insulin for diabetes and chemicals effective against certain forms of cancer, have encouraged the notion. Using the term health provider to mean a physician epitomizes this view.
However, dependence on medicine as the source of health tends to obscure far more fundamental influences on health. For millennia it has been evident that living conditions and the response to them largely determine people's health. Therefore, people have sought to extend life and improve health not only as individuals but also through communal efforts in the societies of which they are a part. These social efforts to enhance the health of whole populations have come to be called public health, "what we, as a society, do collectively to assure the conditions in which people can be healthy" (Institute of Medicine, p. 1). In modern times, government plays the leading role in this endeavor, supplemented by other endeavors organized to advance the health of the public. Making medical services available to people is only one way in which modern industrialized societies address health challenges; other measures include assuring a healthful environment and encouraging healthful behavior by individuals. To carry out its mission, public health must establish effective linkage with other efforts for social advancement, particularly in welfare and education.
Public health measures its progress by the health status of the population it serves. Thus, knowing the determinants of the public's health (which is also known as public health) is essential to the field.
Advances in Health, 1800–2000
The period since 1800 has brought the most spectacular health improvement in human history. From the time of the hunter-gatherers thousands of years ago until the industrial revolution around 1800, Mark Cohen estimates that life expectancy at birth ranged consistently between twenty and fifty years, most commonly about twenty-five to thirty years (Cohen). At the end of the twentieth century, life expectancy exceeds sixty-five years in most parts of the world and seventy-five years in western Europe, North America, and Japan.
In the United States, for example, life expectancy was only forty-seven years when the twentieth century began. By the late 1980s it had reached seventy-five years, according to the National Center for Health Statistics (1990). To a considerable extent that advance was due to declining infant mortality, from more than 100 per 1,000 in 1900 to less than 10 per 1,000 in the late 1980s, and to the control of communicable diseases, which take their major toll during the early years of life. Since 1960, however, relatively greater extension of life has occurred in the later years. From 1900 to 1960 life expectancy at birth increased twenty-two years, but only one-tenth of that expansion came after age sixty-five. Since 1960, on the other hand, more than half of the five years gained in life expectancy at birth have come beyond age sixty-five.
Table 1 lists specific diseases, and their trends, that have affected residents of the United States since 1900. Medical students in the early 1900s learned about pneumonia as "the old man's friend" and tuberculosis as "the captain of the men of death." Heart disease at the start of the century largely came from rheumatic fever, whereas now atherosclerosis accounts overwhelmingly for heart disease. Population aging considerably influences death rates from cancer and heart disease. Even when adjusted for age, however, cancer mortality has been increasing, mainly because of the twentieth-Century epidemic of lung cancer. A rare form of the disease in 1900, respiratory cancer increased to constitute about one-tenth of all cancer deaths in 1950 and almost one-third as the century closed. Other measures of health status, such as survival to age sixty-five, reveal the role of violence and injury in certain human populations, such as young males in the United States.
Historical Determinants of Health
Health may be viewed as the human side of a dynamic equilibrium between the organism and its environment; that interface is the place where health is mainly determined.
The genetic structure with which humans enter the world will generally allow survival for about eighty-five years, according to James Fries (1980). In some people, of course, hereditary abnormalities interfere with and/or shorten life, while others live more than eighty-five years in reasonably good health. Beyond these biological influences, since food and oxygen are the most critical elements for human life and since oxygen is only rarely inadequate, nutrition constitutes a paramount factor in health. From earliest times to the present, inadequate food has been a major threat to health. In fact, society has evolved largely to supply enough food for people—for example, through migration and the development of agriculture.
Not infrequently, however, huge numbers of people have been trapped in starvation through ecological and social catastrophes—both in ancient times and more recently, as in the Irish potato blight of the late 1840s and in slavery in the United States, and now in certain African nations and among the homeless in America. Moreover, beyond gross lack of calories, deficiencies of vitamins and
|Crude Death Rates per 100,000, Selected Causes, U.S. Registration Area, 1900–1988|
|Cause of Death||1900||1920||1940||1970||1980||1988|
|SOURCE: Linder, Forrest E., and Grove, Robert D., 1943; Stie glitz, Edward J., 1945; U.S. Bureau of the Census, 1990.|
|Organic heart disease||123||151||296||362||336||312|
other micronutrients cause incalculable damage to health—incalculable because scurvy, rickets, and pellagra may be only the most striking clinical manifestations of severe damage to health.
Industrialization, even though it has improved the standard of living in many respects, has also precipitated some devastating health events. In the early 1800s, when people flocked from the countryside to factory towns and cities in search of a better life, they found crowded housing, gross lack of sanitation, and exhausting work (even for children), as well as food deficiencies. These living conditions produced the "crowd" diseases, epidemics spread by intestinal and respiratory discharges that debilitated many people and caused high mortality. Though all segments of society were affected, the poor suffered then, as throughout history, most severely from the adverse conditions.
While medical science has helped in overcoming the communicable disease epidemics since 1800, other factors have been even more important. John and Sonja McKinley have estimated that at most 3.5 percent of the total decline in mortality (from influenza, pneumonia, diphtheria, whooping cough, and poliomyelitis) since 1900 could be ascribed to medical measures (McKinley and McKinley). Thomas McKeown has demonstrated that medical science barely affected the decline of tuberculosis (McKeown).
During the twentieth century a constellation of noncommunicable diseases, led by cardiovascular disease and cancer, has supplanted the epidemic communicable diseases as the foremost health problem in industrialized countries (despite the current public attention to AIDS); and increasingly such noncommunicable diseases are affecting the rest of the world. Again, the circumstances of life and the way people behave in them are the major determinants. For example, the first to indulge in excessive calories, fats, cigarettes, and physical inactivity were affluent men, and accordingly they suffered consequent ischemic heart disease first. Poor men—for example, blacks in the United States—only later had considerable access to those relevant factors; their epidemic of ischemic heart disease came later and is persisting longer.
Major Current Influences on Health
Epidemiological studies have delineated key factors in the rise and the start of the decline of twentieth-century noncommunicable diseases. Most noteworthy, in 1964 an advisory committee to the U.S. surgeon general summarized the growing evidence that "Cigarette smoking is causally related to lung cancer in men … the most important of the causes of chronic bronchitis in the United States … [and is associated with] … a higher death rate from coronary artery disease …" (U.S. Surgeon General's Advisory Committee, pp. 31–32).
Studying a sample of the Alameda County, California, population, Nedra Belloc and Lester Breslow demonstrated the strong relationship of seven health practices to health status and subsequent total mortality: eating moderately, sleeping seven to eight hours, using alcohol moderately if at all, not smoking, eating breakfast, not snacking, and having at least moderate physical activity (Belloc and Breslow). Men who followed all seven health practices enjoyed physical health equal to that of men thirty years younger who reported two or fewer. Forty-five-year-old men who followed none to three of the health practices had a longevity of sixty-seven years; four to five, seventy-three years; and six to seven, seventy-eight years, thus yielding an advantage of eleven years, depending upon health behavior. Lisa Berkman and Lester Breslow reported further that the extent of one's social network likewise substantially predicted physical health status and mortality (Berkman and Breslow). A 1974 official Canadian document, the LaLonde Report, proposed a health field concept. According to the latter, four broad elements comprise the health field: human biology, environment, and lifestyle, and healthcare organization. Further, the LaLonde Report asserted that "Improvements in the [social as well as physical] environment and an abatement in the level of risks imposed upon themselves by individuals, taken together, constitute the most promising ways by which further advances can be made."
The growing emphasis on the way people live as an important health factor in the industrial (and postindustrial) world must be considered carefully in relation to social responsibility for lifestyle. Otherwise, that emphasis can properly be termed "victim blaming." A 1952 report to the president of the United States, Building America's Health, noted that "Recognition of the significance of individual responsibility for health does not discharge the obligation of a society which is interested in the health of its citizenry. Such recognition, in fact, increases social responsibility for health" (President's Commission on Health Needs of the Nation, vol. 1, p. 2). As the Ottawa Charter for Health Promotion stated, "Health promotion is the process of enabling people to increase control over and to improve their health. … [It] … demands coordinated action by all concerned: by governments, by health and other social and economic sectors, by non-governmental and voluntary organizations, by local authorities, by industry, and by the media" (International World Health Organization Conference, p. 1).
As it becomes clear that we are able to raise life expectancy to some sort of biological limit, it may well be that public health rather than gross national product (GNP) will constitute the criterion for national success. Using public health as a standard for this success would help illuminate how GNP masks the staggering toll of ill health found among low-income or very poor Americans, many of whom, like American Indians or African Americans, have been disproportionately disadvantaged for generations. Achieving that reorientation of values will require a new approach to the food, alcohol, tobacco, medical, and other industries whose products and services are pertinent to health. Health ethics now entails concern for issues beyond matters in which the physician–patient relationship predominates. How to deal effectively with the "right" to addict young people throughout the world to tobacco and to expose others to one's intoxicated behavior, and similar public-health issues, are coming to the fore. Social action reflecting experience and thought concerning such questions will determine health in the future, just as assuring safe water and milk determined health in the past.
lester breslow (1995)
SEE ALSO: Hazardous Wastes and Toxic Substances; Health and Disease: History of Concepts; Health Screening and Testing in the Public Health Context; Injury and Injury Control; Lifestyles and Public Health; Public Health Law; Sexual Behavior, Social Control of;Warfare: Public Health and War; and other Public Health subentries
Belloc, Nedra B., and Breslow, Lester. 1972. "Relationship of Physical Health Status and Health Practices." Preventive Medicine 1(3): 409–421.
Fries, James. 1980. "Aging, Natural Death, and the Compression of Morbidity." New England Journal of Medicine 303(3): 130–135.
Institute of Medicine (U.S.). Committee for the Study of the Future of Public Health. 1988. The Future of Public Health. Washington, D.C.: National Academy of Sciences.
International World Health Organization Conference on Health Promotion. 1986. Ottawa Charter for Health Promotion. Ottawa: Author. Sponsored by WHO, Health and Welfare Canada, and Canadian Public Health Association.
LaLonde, Marc. 1974. A New Perspective on the Health of Canadians: A Working Document. Ottawa: Government of Canada.
Linder, Forest E., and Grove, Robert D. 1943. Vital Statistics Rates in the United States, 1900–1940. Washington, D.C.:U.S. Government Printing Office.
McKeown, Thomas. 1988. The Origins of Human Disease. Oxford: Basil Blackwell.
McKinley, John B., and McKinley, Sonja M. 1977. "The Questionable Contribution of Medical Measures to the Decline of Mortality in the United States in the Twentieth Century." Milbank Memorial Fund Quarterly 55(3): 405–428.
Stieglitz, Edward J. 1945. A Future for Preventive Medicine. New York: Commonwealth Fund.
U.S. Bureau of the Census. 1990. Statistical Abstract of the United States, 1990, 11th edition. Wshington, D.C.: U.S. Dept. of Commerce, Bureau of the Census.
U.S. Department of Health and Human Services. Public Health Service. Centers for Disease Control and National Center for Health Statistics. 1991. Health, United States, 1990. Hyattsville, MD: Author.
U.S. President's Commission on Health Needs of the Nation.1952. Building America's Health. 5 vols. Washington, D.C.:U.S. Government Printing Office.
U.S. Surgeon General's Advisory Committee on Smoking and Health. 1964. Smoking and Health: Report. Public Health Service Pub. no. 1103. Washington, D.C.: U.S. Government Printing Office.