PRACTICE OF PUBLIC HEALTH

The phrase "practice of public health" (which will be used interchangeably with the term "public health practice") fails to evoke a single compelling image, even for public health professionals who have spent years working in the field. Unlike medicine, or law, or even engineering, both those who contribute to and those who benefit from public health practice's efforts poorly understand what it is and how it works. This article seeks to illuminate key aspects of public health practice by addressing the following basic questions:

• What is public health practice?
• Where did it come from?
• What does it do?
• How is it organized and structured?
• What challenges does it face in the twenty-first century?

WHAT IS PUBLIC HEALTH PRACTICE?

One approach to describing public health practice is to compare it to some similar activity that most people understand and appreciate. Medical practice appears to fit this bill. The major functions of medical practice are to diagnose diseases and other conditions, develop a treatment plan for those health problems, and see that the treatment regimen achieves its therapeutic goals.

Public health practice has remarkably similar functions that focus on populations rather than individual patients. Public health functions involve identifying health problems and the factors that cause them, developing a strategy to address these problems, and seeing that these strategies are implemented in a way that works. In this light, public health practice is the development and application of preventive strategies and interventions in order to promote and protect the health of populations. Public health practitioners serve the health needs of populations in very much the same ways that physicians tend to the health needs of individual patients. Medical practice focuses primarily on diseases, injuries, and other conditions while public health practice focuses at the community level on factors that contribute to higher rates of these same health problems.

The practice of public health involves both individual and collective efforts. Many different professions and disciplines contribute to public health practice, including public health nurses, nutritionists, health educators, environmental health specialists, and physicians, just to name a few. But public health practice also includes the collective efforts of public health professionals acting in concert with others, often community partners, to identify and address health problems affecting defined populations.

The need for these different disciplines and skills indicates the complexity of the factors contributing to health and disease. Various bacteria and viruses cause many infectious diseases. But other factors can cause or contribute to the development of health problems. For example, the use of tobacco and alcohol contributes to heart disease, cancer, and injuries. Behavioral choices can place an individual at risk of certain infectious diseases (sexually transmitted diseases), chronic diseases (emphysema), injuries (drug overdoses), and other conditions. There are also aspects of the physical environment that affect health (contaminated air, water, or food). The social environment can also determine health risks (low income and education levels, overcrowding, and personal safety). Other social factors related to the use of health and medical services, such as travel distance, the number of providers, and even the availability of day-care services, also influence health. With so many elements affecting health, there is no one body of scientific knowledge that guides public health practice. Instead there are many. These include epidemiology, statistics, environmental sciences, management, biological sciences, and the behavioral sciences such as anthropology, sociology, psychology, and more. Political science, economics, and law are also involved in modern public health practice. Public health is grounded in many different sciences and supported by a variety of other disciplines.

Many people think of public health practice as only those activities performed by governmental public health agencies. Public health practice certainly includes, but is not limited to, the activities of federal, state, and local health agencies (such as the federal Centers for Disease Control, state health departments, and local public health departments). But many other individuals, organizations, institutions, and collaborations contribute to public health practice—and these efforts take place in private and voluntary, as well as in public, settings. For example, hospitals and businesses are often involved in communitywide health fairs and heart and lung associations continuously promote healthy lifestyles.

With so many different participants, the practice of public health can appear to be fragmented and chaotic. But, ideally, public health practice is strategic and purposeful; it is organized (perhaps most effectively at the community level) and it is both interdisciplinary and multidisciplinary. In sum, the practice of public health embodies what a community or society does collectively in order to ensure conditions in which people can be healthy. The skills and competencies necessary for public health practice are both individual and collective.

WHERE DID PUBLIC HEALTH PRACTICE COME FROM?

Many different forces have shaped modern public health practice. These include diseases and other health threats, history, science, social values, and the role of government. Health threats have always challenged human populations; nearly all of the diseases that have wreaked havoc on society over the centuries are still with us today, including tuberculosis, cholera, malaria, yellow fever, and plague. While some diseases have disappeared due to intensive prevention and control initiatives (smallpox is a good example), there is little expectation that all diseases and illnesses can be avoided. The infectious diseases of the past have been joined by dozens of other conditions, most recently by AIDS (acquired immunodeficiency syndrome)—an infection with HIV (human immunodeficiency virus)—and by a host of chronic disease risks and environmental threats. The identification of and responses to these threats, over time and across the globe, especially responses that represent collective decisions and actions, have evolved into what we know as public health practice.

In past centuries, health risks and threats were addressed in a variety of ways. For much of recorded history, diseases were accepted as phenomena beyond human control. Acceptance and avoidance were major strategies as recently as the nineteenth century. For example, when cholera appeared in cities or neighborhoods in Europe and the United States as recently as the mid-nineteenth century, residents (if not immediately infected) could accept the risk or choose to move away until the risk subsided.

While diseases and the microorganisms that cause them have co-habited with humankind for all of history, their spread was greatly aided by industrialism, nationalism, and mercantilism in recent centuries. Industrialism brought previously agrarian societies into urban centers where the population density and unsanitary living and working conditions fostered the spread of many diseases. Nationalism and mercantilism fostered travel and trade across the globe and provided increased opportunities for diseases to be carried from one densely populated area to another. European societies that had centuries of experience with many diseases—and had developed an ecological balance with those diseases through changes in their collective immunological status—brought diseases never before seen to Native-American populations in North and South America. Small wonder that relatively tiny armies of European explorers easily conquered civilizations with much larger populations, encouraging the belief that they were indeed supernatural figures and that the diseases they brought with them were beyond human control.

It was the spread of epidemic diseases largely through seaport towns and cities that prompted the first U.S. public health responses. Boards of distinguished citizens, the first local boards of health, were appointed in cities like Philadelphia, New York, and Chicago to provide the credibility and support necessary to pursue the restrictive policies of quarantining ships and their crews, or placing notices or placards to warn citizens to avoid locations where diseases had occurred. But until the latter part of the nineteenth century, little was known about the causes and pathways of these epidemics. The work of pioneering scientists in the latter half of the nineteenth century, such as Louis Pasteur in France and Robert Koch in Germany, opened the way to the identification of specific microorganisms and eventually to the development of specific approaches to battle those germs and break the chain of transmission.

These scientific advances established that many health threats could be addressed through communitywide interventions, such as those that would ensure clean water supplies and sanitary disposal of human waste and sewage. Public health laboratories were developed to assist in diagnosing new cases so that prevention and control activities could be put in place to avoid further spread. Immunizations were developed from these scientific advances and provided to susceptible populations through massive vaccination programs. Because these efforts required both citizen support and public resources, local governments became increasingly involved in public health responses. State governments became active at a slightly later stage, primarily because infectious disease risks did not respect municipal boundaries.

The increasing involvement and expectations for governmental participation in public health responses represents an important facet of public health practice. The U.S. system of government divides duties and responsibilities between the federal government and the states. There are no specific powers related to protecting or promoting the health of its citizens identified for the national government in the U.S. Constitution. As a result, the basic responsibility for health and public health resides with the states and, as established by those states, with local governments. The federal role in health has nonetheless grown, especially over the twentieth century, as a result of its ability to pursue health goals as a power implied (though not explicitly stated) by the Constitution to promote the general welfare. With immense resources available through the federal income tax and with the ability to influence the activities of state and local governments by offering financial resources for specific programs and services through "grant in aid" mechanisms, the federal government emerged as an important player in the health field. Later its role as a major purchaser of health services through massive national programs such as Medicare and Medicaid brought the federal government even greater power and influence in the health sector. Today it maintains a substantial role in health and public health.

The extensive social and economic chaos accompanying the Great Depression in the 1930s raised public expectations that government would involve itself in protecting the health and welfare of all U.S. citizens. Prior to this time, most Americans didn't want government to have powers over their lives and welfare. Government's role as an important force in public health arose out of other needs as well. Only government can implement and enforce some of the policies and interventions necessary to battle health risks—ensuring safe public water supplies and effective municipal sewage disposal programs, for example, or investigating contacts of persons diagnosed with infectious diseases. To the extent that public resources are utilized for these ends, governmental forums are the appropriate places for these decisions. This is but one of the unique features of public health practice, its link with government. But there are several others that have come to distinguish public heath from other forms of health practice.

The public nature of public health practice means it must depend on social values and popular support for both its ends and its means. This makes public health practice inherently political in that different values and perspectives exist in various communities as to what needs to be done about important public policy problems. These sentiments and viewpoints change over time and, as a result, the problems to be addressed by public health practice have changed over time as well. For example, infectious diseases were major concerns through the middle of the twentieth century. Chronic diseases became a major focus after the middle of the twentieth century, as did problems and gaps in the health system. Mental health and substance abuse issues became priorities in the 1970s and 1980s, while the 1990s saw violence emerge as a new problem for the public health practice agenda. The ever-changing agenda of public health practice reflects the dynamic nature of its two most influential forces: science and social values. While public health practice is grounded in science, what we choose to do with that scientific knowledge is determined by social values.

One of the most unique features of public health practice is its basis in social justice. Social justice seeks to distribute the benefits of science and technology equally among all segments of society. In the case of health benefits, this would mean eliminating disparities in mortality, disease incidence, disability, and the like. With the considerable differences in health status and outcomes between African Americans and European Americans, for example, or between rich and poor, it is clear that not all parts of the U.S. population share health benefits equally. These social links help explain why public health practitioners share an uncommon bond: the commitment to improve the health status of others.

WHAT DOES PUBLIC HEALTH DO TODAY?

The complete description for public health practice has yet to be written. The simplest and most straightforward depiction of what public health practice is all about today is best illustrated in the mission, vision, and functions outlined in the "Public Health in America" statement. This one-page document was developed to become the hymnal from which all public health practitioners would sing in the twenty-first century.

The statement articulates a vision (healthy people in healthy communities), a mission (promoting physical and mental health and preventing disease, injury, and disability), and statements of what public health practice does and how it accomplishes those ends. Six broad commitments characterize what public health does. Public health:

• Prevents epidemics and the spread of disease.
• Protects against environmental hazards.
• Prevents injuries.
• Promotes and encourages healthy behaviors.
• Responds to disasters and assists communities in recovery.
• Assures the quality and accessibility of health services.

How public health practice accomplishes these objectives and serves its mission is characterized by ten essential public health services that seek to:

1. Monitor health status to identify community health problems.
2. Diagnose and investigate health problems and health hazards in the community.
3. Inform, educate, and empower people about health issues.
4. Mobilize community partnerships to identify and solve health problems.
5. Develop policies and plans that support individual and community health efforts.
6. Enforce laws and regulations that protect health and ensure safety.
7. Link people to needed personal health services and assure the provision of health care when otherwise unavailable.
8. Assure a competent public and personal health care work force.
9. Evaluate effectiveness, accessibility, and quality of personal. and population-based health services.
10. Provide research for new insights and innovative solutions to health problems.

These statements establish a high standard for performance. But by many different measures of performance, it appears that public health practice has not fully achieved these standards. Signs of sub-optimal performance include continuing high rates of morbidity, mortality, and disability for many conditions; huge disparities among various segments of the population; and persistently unequal access to health services. Improvement in these areas requires a well organized and effectively functioning system of public health practice.

HOW IS PUBLIC HEALTH PRACTICE ORGANIZED AND STRUCTURED?

The final decades of the twentieth century witnessed a series of examinations and initiatives that changed the face of public health practice. These began with a landmark report issued by the prestigious Institute of Medicine (IOM) in 1988 entitled The Future of Public Health. This report examined the state of public health practice in the 1980s and concluded that the public health system was in a state of "disarray" and that it required a major reengineering effort.

The report proposed that governmental public health organize around three broad functions: assessment, policy development, and assurance. Basically these translate into identifying what should be done (assessment), what will be done (policy development), and achieving those ends (assurance). Identifying what should be done comes from a comprehensive and broadly participatory assessment of needs and assets and involves both science and values. Determining what will be done recognizes that not all needs can be met, and that some needs are more important than others. Achieving agreed-upon ends involves evidence-based decisions about what works and what doesn't in a particular setting and about who needs to be involved in community interventions.

Some needs are identified by scientific means, such as data showing higher death rates from cardiovascular disease in a community or from reports of an increasing number of AIDS cases. However, other needs are identified by the willingness of people and organizations to mobilize over problems and issues that are important to them and their communities. In some instances, problems are identified for which there may not be convincing data. Yet these problems can be given as high or even higher priority than those advanced by the so-called experts. For example, a community may decide that leaf burning is a more important public health problem than childhood lead poisoning even when the number of reported cases of elevated blood lead levels is much greater than illnesses that are linked to leaf burning.

The IOM report also outlined a series of recommendations for strengthening the ability of the public health system to carry out its core functions. A number of these recommendations were embraced by the public health community and were reflected in initiatives appearing in the early 1990s. These initiatives closely track the core functions framework of the IOM report.

To establish a national agenda for public health and prevention, an extensive set of national health objectives to be achieved by the year 2000 was established. These Healthy People 2000 objectives were actually the second attempt at establishing a national agenda for health in the United States. The first effort was launched in the late 1970s by then Surgeon General Julius Richmond culminating in the nation's first national health objectives targeting the year 1990. The sequel to Healthy People 2000, Healthy People 2010, builds on both earlier efforts but includes an expanded focus on public health practice and the public health infrastructure. Healthy People 2010 seeks to increase the quality and years of healthy life for everyone and to eliminate health disparities by means of three strategies: promoting healthy communities, preventing and reducing diseases and disorders, and promoting healthy behaviors. Improving systems for personal and public health services is an overarching concern.

Another major public health practice initiative spawned by the IOM report was the Assessment Protocol for Excellence in Public Health (APEXPH). This was developed as a tool to facilitate the local public health leadership capacity of local public health agencies. There were two major elements of APEXPH: One was an extensive organizational self-assessment tool and the other was a framework for developing a community health action plan. Both elements of APEXPH were developed to promote greater emphasis on implementing the IOM report's core public health functions. Both elements also established a new standard of organizational and community practice for local health departments in the United States and many—but certainly not all—of the nation's 3,000 plus local health departments incorporated one or both elements.

The increased emphasis on community health planning through the development of assessments of community health needs and coordinated plans for addressing those needs evolved slowly over the 1990s. In many states and localities these were new roles for local health departments. These agencies often lacked the skilled staff, data and information resources, and links to their communities needed to carry out these duties effectively. However, there was general agreement in the public health practice community that these were necessary and appropriate roles for local health departments and initial efforts were often successful at engaging community partners.

The Institute of Medicine developed a second report on community health improvement in 1997 promoting an enhanced community health improvement process that would link community partners to specific roles in community health plans by means of specific performance measures. At the same time, a variety of other community health planning initiatives were also flourishing as hospitals, health plans, civic organizations, and health professionals began to promote similar processes. The National Turning Point Program was established in 1997 by two national foundations (Robert Wood Johnson and Kellogg) to reform the practice of public health at the state and local level through demonstration projects in fourteen states and more than forty local jurisdictions. Seven more states were added in 1999. Turning Point initiatives generally involved extensive state and local partnerships, seeking to include a wide array of partners and stakeholders from the health field and other sectors of society. For example, business, religious, educational, law enforcement, and community organization leaders joined their counterparts from public health, mental health, substance abuse, and organized medicine.

These initiatives have brought greater attention to the underlying foundation, or infrastructure, of public health practice. The infrastructure of public health can be described in at least two different ways: what it is and what it does. The first view of the infrastructure looks at the basic building blocks of the public health system, while the second looks at what those building blocks actually do. The second view correlates closely with the individual and collective practice of public health.

The most important structural elements of the public health system fall into categories such as work force, information resources, organizational relationships, and financial resources. The public health work force has been very difficult to assess in terms of its numbers, work settings, component disciplines, and skill needs. Rough estimates indicate that there are about 500,000 public health professionals in federal, state, and local public agencies, but that most lack formal training in public health. Public health workers outside these agencies may number several times that of those working for governmental health agencies. Among the largest occupational categories in the public health work force are public health nurses, environmental health specialists, health administrators, and health educators. Several national panels have identified public health competencies as essential for a wide variety of health disciplines. Universal competencies for graduate level public health workers have also been identified. These include: analytical skills, communication skills, policy development and program planning skills, cultural skills, basic public health science skills, and financial planning and management skills.

Data and information drive public health practice in terms of identifying important health problems, determining the factors causing those problems, establishing priorities, communicating with policymakers and the media, and evaluating the effectiveness of various programs and services. Increased access to information through the Internet, integrated information systems, and other collaborations could support expanded and more effective participation in planning, policy development, and assurance activities.

Local public health agencies, frequently called health departments, acting in concert with state health agencies, are often the vanguard of the public health assault on health problems. While key players, these governmental agencies require extensive collaborations and partnerships to be successful. In some instances, outdated public health laws and regulations inhibit effective action on the part of an official health agency and its potential collaborators.

The level of financial resources supporting public health practice is not precisely known. Estimates are that about 1 percent of all health expenditures, or about $40 for every man, woman and child in the United States, supports communitywide prevention programs. When all activities included in the essential public health services framework are included, the total spending for public health practice approximates $50 billion, or about $200 per capita. In comparison, nearly $4,000 per capita is spent each year on medical care services for every person in the United States. National objectives for each of these components of the public health infrastructure are included in Healthy People 2010.

WHAT CHALLENGES DOES PUBLIC HEALTH PRACTICE FACE IN THE YEAR 2001 AND BEYOND?

Public health practice faces many challenges. There are scores of continuing health problems (such as cancer and injuries), emerging health problems (such as AIDS and violence), and re-emerging ones (such as tuberculosis), and a slew of new issues on the public health practice agenda. While health status has never been better (as measured by life expectancy and infant mortality), the gains have not been shared equally by all segments of the population. These widening differences reflect the increasing gap between the "haves" and the "have-nots" in U.S. society and the widespread prevalence of negative social determinants of health among subpopulations in the United States and entire societies across the globe. Despite the most expensive and effective medical services in the world, health status gains have not kept pace with immense investments and the United States health system continues to focus on illness rather than health. These unacceptable realities challenge public health practitioners' core values of realizing public health's dream of social justice and creating a health system organized around health. To meet the challenges, public health practice will have to relearn the lessons of its past and move to expand its circle to include new sectors of society at every level of government—namely, more community partners and stakeholders and a more involved citizenry.

In sum, further improvements in health status that eliminate disparities in outcomes remains the greatest challenge to the practice of public health. A continuing commitment to realize the dream of social justice in health will, in all probability, continue to drive public health practice in the twenty-first century.

Bernard J. Turnock

(see also: Assessment of Health Status; Cardiovascular Diseases; Future of Public Health; HIV/AIDS; Institute of Medicine; Koch, Robert; Malaria; Mortality Rates; Pasteur, Louis; Plague; Smallpox; Tuberculosis; Violence; Yellow Fever )

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