Public health strategies
Surveillance and monitoring
The backbone of public health strategy is the development, implementation, and maintenance of an accurate reliable health information or surveillance system. Donald A. Henderson, who led the successful campaign to eliminate smallpox, has said that ‘surveillance serves as the brain and nervous system for programmes to prevent and control disease.’ The elimination of smallpox from the world would not have been possible without effective surveillance. Surveillance can be used to establish the extent and distribution of a disease and the prevalence of risk factors or behaviours for disease in the population, to monitor the trends of disease or health factors in the community, to establish appropriate programme priorities and allocate resources, and to evaluate the impact of intervention strategies.
Surveillance systems can include information on the occurrence of infectious and chronic diseases, environmental information (including occupational exposures), behavioural characteristics of the population, and availability of medical facilities. It has become increasingly apparent that many infectious and chronic diseases and risk factors for them are determined by human behaviour. Thus, to implement effective intervention strategies it is necessary to know the behavioural characteristics of the population, including their sexual behaviour, and whether it is changing over time. To be most useful, information must be collected on a regular basis and reported rapidly while action in response to the information is still likely to be effective, particularly for infectious diseases and hazardous environmental/occupational exposures. Tardy information about disease outbreaks or sudden environmental exposures such as radiation hazards, for example, precludes the early implementation of effective intervention procedures when they are most likely to be effective. Surveillance systems are expensive to implement and maintain so it is important that they be evaluated periodically to assure that they remain cost-effective and are providing the information which is essential for the resolution of contemporary problems.
The most extensive experience in surveillance work has concerned the communicable diseases. There are fewer mechanisms for reporting chronic diseases, other than mortality. Currently, surveillance for environmental hazards and occupational exposures is even less satisfactory than surveillance for either infectious or chronic diseases. Most urban areas in developed countries have systems for monitoring quality of air and quality of water for human consumption, although provisions for monitoring new contaminants, such as cadmium and magnesium, have been inadequate. Considerable attention also needs to be directed to surveillance of recreational waters, toxic dump sites, and radiation sources. In addition, workers continue to be exposed to unsafe working conditions, particularly in small industries which are more difficult to monitor and regulate. Until permanent information systems which provide reliable, accurate, and rapid reporting of all principal factors affecting community health can be implemented, effective programmes cannot be fully realized. Implementation of effective surveillance is particularly difficult in developing countries that have limited resources or fewer health professionals with the necessary expertise. Yet, it is developing countries that have the greatest need for information on the prevalence of disease and risk factors for disease.
Effective intervention forms the heart of public health efforts to protect communities from health hazards. These efforts include reducing the number of individuals vulnerable to infectious and chronic diseases, treating people early in the course of disease, modifying the environment, and promoting healthy behaviour of both communities and individuals.
Technological advances play a key role in developing effective intervention programmes, but often implementation of these programmes depends on the use of innovative epidemiological strategies, behavioural modification of individual lifestyles, and changing the political will of the community. For example, a satisfactory vaccine for smallpox existed for centuries before eradication was made possible by changing from an untargeted mass vaccination approach to an active surveillance and containment strategy supported by adequate resources. Legislation to control tobacco use by increasing the tax (and therefore the price) of tobacco products, restricting advertising for them and the places they can be used, denying access to youngsters, and requiring warning labels can change the whole social milieu regarding tobacco use and thus reduce it substantially, as has happened in California. Likewise, reduction of air pollution has been achieved by legislation requiring necessary corrective action after inspection of vehicles for pollutant levels and curtailing industrial pollution of the atmosphere.
Epidemiological research has identified many risk factors for cardiovascular disease, but implementation of intervention strategies to reduce these risk factors depends on convincing people to alter their basic habits such as diet and exercise. Methods for prevention of most sexually transmitted diseases, including AIDS, are well known, and treatment of many of them has been available for decades. Nonetheless, efforts to reduce the incidence of these diseases have been largely unsuccessful because of the difficulty of modifying this most intimate aspect of lifestyle. The source of many of the pollutants affecting the major cities of both the developed and the developing world are known, but techniques to reduce these pollutants involve major expenses by both the public and industry, and often cause inconvenience for the public.
Intervention through legislation typically invokes strong resistance, but that resistance can be overcome as has been demonstrated with the reduction of water and air pollution in Los Angeles through legislation that regulates industrial wastes and vehicle emissions. Changing the public’s concept of what is socially acceptable can result in change, as has been demonstrated by the current attitude towards smoking in the United States and the current attitude towards vehicles that obviously pollute the environment in many cities of the developed world.
In summary, successful public health intervention is the result of technical advances coupled with the use of innovative epidemiological strategies, education of the public about the need for intervention, implementation of effective behavioural modification techniques, and induction of the political will.
An essential component of public health strategies is evaluation. The effectiveness of surveillance and intervention programmes changes over time due to changes in the incidence of disease, the development of new health hazards, and the development of new technologies for measurement and control. Thus, evaluation should be an ongoing, integral part of all public health surveillance and intervention programmes. For many years vaccination of all people in the United States against smallpox persisted even though the risk of an adverse outcome was greater from the vaccine than the risk of acquiring smallpox. Ultimately, the worldwide eradication of smallpox eliminated the need for vaccination against that disease. Since any immunization is associated with some adverse reactions, continued use must provide more benefit than risk. Because this ratio changes in relation to many factors, the relationship must continually be re-evaluated.
The effectiveness of different strategies of community intervention for promotion of healthy lifestyles can also be evaluated. Numerous studies have demonstrated, for example, that providing information about health hazards is seldom sufficient to motivate people to change their lifestyle.
Evaluation of environmental intervention has progressed less rapidly, partly because of the need for appropriate technology to identify and measure levels of pollutants in air, water, land, and the workplace, and partly because of the difficulty in identifying disease outcomes that may take years of chronic exposure. There is a need for earlier markers of disease processes resulting from exposure to pollutants which would permit faster evaluation. The cost of implementing environmental controls means that the public will be unlikely to pay for controls that have not been evaluated and demonstrated to result in improvement in health.
In summary, surveillance, intervention, and evaluation are the backbone of public health strategies to prevent disease, eliminate health hazards, and promote health in the community.
Organization of public health
Organization of health services, both public and private, is largely conditioned by the cultural, political, and organizational patterns of the countries in which they are located. Thus in the United Kingdom and many European countries a national health service covers preventive, community, and clinical health services. Conversely, in the United States the tendency has been towards state and local governmental autonomy in environmental and health education services and medical care for the indigent population. Clinical services have been left principally in the private sector with federal governmental payments only for limited segments of the population.
The United States constitution provides for the states to relinquish only those governmental powers that are essential to maintain the union. Accordingly, state and local governments historically have taken the main responsibility for public health, with most programmes being conducted at the local level under state regulation and only broad directions and incentives provided by the federal government. Thus the local jurisdictions (the county, city, or township), through authority delegated from the states, typically have undertaken communicable disease surveillance and control, maternal and child health services, environmental surveillance and control, and other traditional public health activities.
The role of the federal government in public health has evolved for the most part on a piecemeal basis. Usually it has assumed responsibility for meeting those needs not otherwise met by private, local, or state agencies. Generally, these initiatives have been categorical in nature, directed primarily at specific disease problems, such as cancer, or towards segments of the population, such as the poor. Exceptions to this approach have been the creation of the National Institutes of Health, the major research funding source in the United States, certain regulatory agencies such as the Environmental Protection Agency and the Food and Drug Administration, and the agencies and programmes stemming from the 1935 Social Security Act, the basic social security legislation for the nation.
Healthy People 2000, the National Promotion and Disease Prevention Objectives (US DHHS 1991), and other United States government documents do not have the force of legislation but serve as important guidelines and encouragement for local health agencies. The role of the federal government thus remains largely to suggest and encourage actions (sometimes with specific subsidies) that are either implemented (or ignored) at the local level.
In the European nations the philosophy of central control of public health has predominated, perhaps because of their smaller size and more homogeneous populations. The majority of the European nations have a national health scheme that is administered federally. Thus, to a larger degree than in the United States, public health activities are implemented centrally through an organized system.
The presence of a national health scheme, however, has not guaranteed more effective public health programming. Often the agencies within these federal governments do not command the respect and resources accorded the clinical components and therefore are not as effective as they could be. Also, many European countries lack schools of public health or their equivalents to prepare professionals for public health careers. Nonetheless, equity in access to medical care has generally been greater in the European systems than in the United States.
Whatever the government structure for public health, the need for good management is increasingly recognized. The responsibility for handling budgets that are often substantial, complex organizations involving many different categories of people, and maintaining effective relationships with a wide array of health agencies as well as other bodies, requires great managerial skill. The inadequate preparation in management skills of many health professionals who have previously occupied public health administrative posts has induced some governing authorities to call upon ‘managers’ rather than public health experts for the key positions in public health. This is increasingly true in the United States. Too often, public health administration has been reduced to budget control or complying with already adopted laws and regulations. As a result, little attention is given to analysing health problems or devising innovative solutions. The ideal is to combine the talent for leadership in public health with managerial skill.
In the developing countries the organization of public health is determined to a greater extent by economic and developmental considerations. Governments in developing countries tend to provide health services, although not at the level of sophistication available in the developed countries. In most of the developing countries responsibility for public health is usually assumed by the federal government through its Ministry of Health. Typically, a network of public health centres is established at the provincial and local levels, for example, the establishment of a network of anti-epidemic stations in China which are under the broad direction of the federal government. Often these provincial and local centres provide not only the usual public health services, but also provide care at local and provincial hospitals. The poorest of the developing countries also depend to a great extent upon support from non-governmental organizations and international agencies such as the WHO. These organizations do not always share the same vision of public health as the individual countries. Furthermore, they tend to provide assistance for specific diseases or subpopulations which often distort the priorities for health efforts. Health must compete with other governmental priorities for limited resources and often comes out second best. Because of the pressing need to address disease problems, particularly infectious disease problems, and the economic constraints under which they must operate, very few developing countries have developed plans for safeguarding the environment and assuring that it is healthy. Finally, there is often a shortage of health professionals trained in modern public health to design and implement effective public health programmes.
In summary, the organization of public health in various countries appears to be largely determined at every level—local, state, and national—by economic, cultural, and historical factors resulting in a wide array of often complex organizational arrangements.
Non-governmental public health agencies
Voluntary health agencies have flourished in the United States and to a somewhat lesser extent in Europe. They tend to be organized around specific entities: for example, the American Cancer Society, the American Heart Association, and the American Lung Association. Their success has encouraged the development of many more such groups, devoted to practically all the major diseases and several lesser ones.
Typically organized at the national level in the United States, with state divisions and local chapters, these voluntary health agencies bring together health professionals who are leaders in their particular fields and interested members of the public. They involve millions of people in fund raising for, and operation of, disease control activities. In this way they have contributed much to the level of enlightenment and activity concerning health, particularly in the United States. Their programmes usually include support of health research, professional education, public education, and demonstration services devoted to their own particular disease category.
These voluntary health agencies have become a considerable force in public health. They are able to operate with fewer constraints than governmental departments in the developed nations and thus have often broken new ground in the field. The American Heart Association and the American Cancer Society, for example, have been particularly active in bringing the concepts of risk factors and healthy lifestyles before the American public.
In the developing nations non-governmental organizations have played an even more important role in promoting health. Often governments in developing countries are constrained from specific activities by political and economic limitations. Non-governmental agencies, because they are not subject to these constraints, often play a key role in disease intervention and promotion of health. In the poorest countries, however, the health ministries must sometimes subjugate their health priorities to those of the non-governmental organizations because the latter have the funds and the freedom to implement activities that the governments cannot. In extreme cases the different non-governmental organizations may have conflicting health agendas making the setting of priorities by local public health professionals very difficult. Internationally, the increasing importance of non-governmental organizations in assisting the poorest countries to attack their major health problems is reflected in the number of non-governmental organizations recognized and affiliated with the WHO.
Another force in developing public health policy has been private foundations such as the Robert Wood Johnson Foundation, the Pew Memorial Fund, the Kellogg Foundation, the Rockefeller Foundation, and, most recently, the Gates Foundation and the California Wellness Foundation. These foundations support studies and trials of various approaches to health care, medical education, and public health. Thus they often point the way towards new ventures in public health. The Rockefeller Foundation, for example, has fostered an international network of doctors in clinical epidemiology by sponsoring selected training programmes in medical schools in developing countries. This has had a major impact both in promoting epidemiology and in increasing its profile within medical schools in the participating countries. By supporting programmes and studies with particular social and medical implications, these foundations will probably continue to play an important role in influencing public health policy.
The scope of public health in the last part of the twentieth century has expanded greatly (Fielding 1999). Not only have the number of recognized health hazards to the public increased, the strategies available to solve them have grown commensurately. Public health has borrowed and adapted knowledge from the physiological, biological, medical, physical, behavioural, and mathematical sciences, and has been quick to recognize the potential of new fields such as the computer sciences for improving, safeguarding, maintaining, and promoting the health of the community.
As the major communicable diseases have been brought under control through public health measures, more effort has been directed at chronic disease control, mental health, assuring a safe environment, reduction of accidents, violence, and homicide, and promotion of healthy lifestyles in developed countries. Although developing countries must continue to address persisting infectious diseases, they increasingly suffer from the ills of developed countries, particularly degradation of the environment. The biological sciences remain an important underpinning element of public health, but the contributions of the physical, mathematical, and behavioural sciences are increasingly recognized. As in the past, improvements in the health of the public in the future will be achieved by inducing public awareness and concern, which results in behaviour change, and the introduction and passage of effective legislation and regulations that are implemented by professionals committed to the principles of public health.
The previous effectiveness of such efforts, and the realization of the cost-effectiveness of preventive strategies for promoting and maintaining health, have brought renewed attention to public health and have set the stage for a new public health revolution.
Berkman, L.F. and Syme, S.L. (1979). Social networks, host resistance, and mortality: a nine-year follow-up study of Almeida County residents. American Journal of Epidemiology, 109, 186–204.
Breslow, L. (1999) From disease prevention to health promotion. Journal of the American Medical Association, 281, 1030–3.
Breslow, L. and Breslow, N. (1993). Health practices and disability: some evidence from Alameda County. Preventive Medicine, 22, 86–95.
Detels, R., Tashkin, D.P., Sayre, J.W., et al. (1991). The UCLA Population Studies of Chronic Obstructive Respiratory Disease (CORD): X. A cohort study of changes in respiratory function associated with chronic exposure to SOx, NOx, and hydrocarbons. American Journal of Public Health, 81, 350–9.
Fauci, A.S. (1996). AIDS in 1996; much accomplished, much to do. Journal of the American Medical Association, 276, 155–6.
Fielding, J.E. (1989). Frequency of health risk assessment activities at US work-sites. American Journal of Preventive Medicine, 5, 73–81.
Fielding, J.E. (1999) Public health in the twentieth century; advance and challenges. Annual Review of Public Health, 20, xiii–xxx.
Graunt, J. (1662). National and political observations mentioned in a following index, and made upon the bills of mortality. Printed by Thomas Roycroft for John Martin, James Allestry, and Thomas Dicas, London. Reprinted (1939), Johns Hopkins Press, Baltimore, MD.
Green, L.W. and Kreueter, M.W. (1998). Health promotion planning: an education and environmental approach, (3rd edn). Mayfield Publishing, Mountain View, CA.
Institute of Medicine (1999). Leading health indicators for healthy people 2010, Second Interim Report. Committee on Leading Health Indicators for Healthy People 2010, Division of Health Promotion and Disease Prevention, Institute of Medicine. National Academy Press, Washington, DC.
Kuczmarski, R.J., Flegal, K.M., Campbell, S.M., and Johnson, C.L. (1994). Increasing prevalence of overweight amongst United States adults: the National Health and Nutrition Examination Surveys, 1960 to 1991. Journal of the American Medical Association, 272, 205–11.
Last, J.M. (ed.) (1995). A dictionary of epidemiology, (4th edn). Oxford University Press.
McGinnis, J.M. and Foege, W.H. (1993). Actual causes of death in the United States. Journal of the American Medical Association, 270, 2207–12.
Manley, M., Epps, R.P., Husten, C., Glynn, T., and Stropland, D. (1991). Clinical intervention in tobacco control. Journal of the American Medical Association, 286, 3172–84.
Mann, J.M. and Tarantola, D. (ed.) (1996). AIDS in the world. Oxford University Press.
NIAID (National Institute of Allergy and Infectious Diseases) Division of AIDS (2000). Vaccine concepts/designs. Website: http://www.niaid.nih.gov/aids/vaccine/concepts.htm
Pearce, N. (1996). Traditional epidemiology, modern epidemiology and public health. American Journal of Public Health, 86, 678–83.
Rios, R., Poje, G.V., and Detels, R. (1993). Susceptibility to environmental pollutants among minorities. Toxicology and Industrial Health, 9, 797–820.
Robine, J.-M., Blanchet, M., and Dowd, J.E. (ed.) (1992). Health expectancy: studies on medical and population subjects, No. 54. Office of Population Census and Surveys, London.
Smith, G.S. (1985). Measuring the gap for unintentional injuries: the Carter Center health policy project. Public Health Reports, 100, 565–8.
United Nations International Conference on Population and Development (1994). Programme of action. Cairo, Egypt.
US DHHS (United States Department of Health and Human Services) (1980). Promoting health/preventing disease: objectives for the nation. DHHS (PHS) publication No. 79-55071, US Government Printing Office, Washington, DC.
US DHHS (United States Department of Health and Human Services) (1991). Healthy people, national health promotion and disease prevention objective. US Government Printing Office, DHHS publication No. (PHS) 91-50212, Washington, DC.
US DHHS (United States Department of Health and Human Services), National Center for Health Statistics (1998). Health, United States, 1998. US Government Printing Office, Washington, DC.
US DHHS (United States Department of Health and Human Services), National Center for Health Statistics (1999). Health, United States, 1999. US Government Printing Office, Washington, DC.
WHO (World Health Organization) (1996). The global burden of disease (ed. C.I.L. Murray and A.D. Lopez). WHO, Geneva, Switzerland.
WHO (World Health Organization) (1999). Report on infectious diseases. Removing obstacles to healthy development (publication code: WHO/CDS/99.1). WHO, Geneva, Switzerland.
WHO (World Health Organization) (2000). Global polio eradication initiative strategic plan 2001–2005 (publication code: WHO/Polio/00.05). WHO, Geneva, Switzerland.
1.1 Current scope and concerns in public health (cont’2)
Public health strategies