Introduction to Public Health

Welcome to an

introduction

to

public

health

. My name is Susie McCarthy. As a

health

education specialist at CDC, I have worked in various areas of

public

health, including children's health, infectious diseases, chronic diseases, and most recently, public health workforce development. Public health is a dynamic and multidisciplinary field, as you will see in this introductory course. This slide shows the course outline. We'll start by looking at the purpose of public health and some key terms. Then we will look at some events in the history of public health. Next, we will analyze the public health approach and apply it to a public health problem.

We will then cover the main functions and essential services of public health to show the broader context and identify the different groups that have an interest in public health. Finally, we will discuss the factors that determine health and I will present the health impact pyramid as a framework for influencing public health at different levels. This introductory course should allow you to achieve the learning objectives on the slide that align with the course outline I just covered. What then is public health? CEA Winslow was a leading figure in the development of the modern study of public health.

Read this definition of public health that she developed almost a century ago and consider key words or phrases in the definition that speak to you or tell you what public health is. You may notice that, as a combination of science and art, public health offers many opportunities to be creative. Public health is not only about preventing and treating diseases, but also about promoting good health. Winslow says this is accomplished through organized efforts. What then are some examples of organized efforts? She might think about how national surveillance systems are set up, how our waste management infrastructure is built, or how the latest vaccination recommendations are developed and communicated.

From Winslow's definition, it can be seen that public health provides people and organizations with information to help them make decisions that inform them and help them improve their health or the health of others. Public health also occurs at different levels. At the individual, organizational and community level, and even more broadly at the city-state, national and international level. Here are two statements about the mission of public health. The Institute of Medicine says there is a societal interest in ensuring conditions in which people can be healthy, and we will return to the concept of assurance later in the course.

The World Health Organization, or WHO, says that public health is about serving the common good. The maximum benefit for the greatest number of people. From these two statements it can be seen that public health focuses on groups of people and not just individuals. And at the center of public health is this principle of social justice. That people have the right to be healthy and to live in conditions that support their health. Now that we know what public health is, let's review some common key terms. Clinical care is the prevention, treatment and management of diseases, and the preservation of physical and mental well-being through health services.

All of this is also more commonly known as medical care or health care. A determinant, also known as a health determinant, is a factor that contributes to the generation of a trait, such as ethnicity or genetic makeup. But more generally, the context of people's lives determines their health, and we will go into more detail about the determinants of health later in the course. An epidemic or outbreak, as you can see on the slide, is the appearance in a community or region of cases of a specific disease or health-related behavior that exceeds what we would normally expect to see in that area.

An epidemic and an outbreak are used interchangeably. However, epidemic generally refers to a broader geographic distribution of diseases or health-related events. It is basically an epidemic that occurs when a disease spreads rapidly to many people. You may also hear the term pandemic, which is a kind of epidemic on steroids. It often has a global impact, meaning people on multiple continents are affected, often crossing borders and entering different countries. A health outcome is the result of a medical condition that directly affects a person's life in terms of its quality or duration. And think about the health outcomes for someone living with HIV, for example, or who has diabetes.

Alright. Now we have come to a knowledge test and I ask you to fill in the blank with the correct answer. Does public health aim to provide groups of people or individuals the right to be healthy and live in conditions that support their health? The answer is groups of people. Public health focuses on populations rather than individuals. The next test of knowledge is to ask: what happens with a disease in a population that exceeds what is expected for a given time and place? Is it a pandemic, intervention, epidemic or outbreak, or prevention? And the correct answer is epidemic or outbreak.

We will now take a look at some historical highlights of public health through the four lenses: sanitation and environmental health, pandemics, disaster response and preparedness, and prevention through policy. Therefore, the first lens to be analyzed encompasses disease control and health promotion through sanitation to ensure a healthy environment. Here are three examples from around the world of how public health has been implemented to contain infectious diseases through environmental measures. Around the year 500 BC. C., it is recorded that the ancient Greeks and Romans actively practiced sanitary measures. Roughly two millennia later, we see the work begun long ago in Greece continued in the United Kingdom through the passing of the Public Health Act of 1848, which established a central board of health and placed responsibilities for sanitation in the hands of municipalities. .

In 1970, in the United States, President Nixon's administration created the Environmental Protection Agency, which still protects our health today by safeguarding the air, water and land. Next we will explore pandemics, and you will remember that they are similar to epidemics, except that they affect even larger populations, often across countries and continents. Thus, influenza has caused pandemics many times both in the distant past and in recent history. Nearly a century ago, the Spanish flu infected 500 million people around the world, including remote islands in the Pacific and Arctic. And it is estimated that it killed between 20 and 50 million people.

More recently, the 2009 flu pandemic infected people in 214 countries and caused nearly 19,000 confirmed deaths. And while 19,000 confirmed deaths is still a lot of deaths, it's nowhere near the kind of death rate we saw about 100 years ago, when the Spanish flu was running rampant. So we've made enormous public health strides in terms of controlling influenza, but preparing for and managing the effects of influenza will likely remain top public health priorities. Historically, polio was a common and much-feared disease that caused serious illness, including paralysis and even death. Thousands of people lined up to receive the polio vaccine after its

introduction

in 1955.

An initiative to eradicate polio was launched in 1988 due to outbreaks in more than 125 countries. And thanks to those efforts, polio currently exists in only a few countries. Finally, with our last example, during the 1980s, the human immunodeficiency virus, or HIV, emerged and spread rapidly throughout the world. Public health has responded to this pandemic by developing new ways to diagnose and treat those who are infected. New HIV infections have decreased by 20% in the last 10 years, and that is a sign that public health interventions are succeeding. So the third area we will explore is the role of public health in disaster preparedness and response, both for natural disasters and man-made threats.

The use of biological warfare to infect people and animals dates back centuries. One of the oldest accounts is the use of the plague as a weapon of war during the siege of Caffa in the 14th century AD. And Caffa is now an area where modern-day Ukraine is located. So back then, the attacking Tatar forces probably catapulted corpses full of plague infection into their enemy's city. This contributed to the spread of the Black Death in that area. During disease outbreaks that today could be linked to bioterrorism, the public health community is prepared to distribute life-saving pharmaceuticals in the form of antidotes, medical supplies and equipment to locations across the country and even the world.

In the wake of the terrorist attacks on the United States on September 11, 2001, which I'm sure you all remember, public health workers were at the World Trade Center and the Pentagon to conduct surveillance to identify outbreaks of diseases and health conditions. that could have resulted from the attacks. Public health workers monitored the occupational health of first responders and city residents, as well as environmental conditions to detect health threats after the attacks. Public health also responds to natural disasters. After Hurricane Katrina hit in 2005, public health workers joined disaster relief agencies to provide emergency services and sent teams to conduct disease and injury surveillance among residents at home and those who had been relocated to shelters.

So the last lens we will look at when analyzing the history of public health is health policy as a means of prevention. We implement a variety of policies in public health areas to support efforts at the societal level. Already in the year 1500 BC. C., Leviticus, the third book of the Hebrew Bible, is believed to be the first written health code in the world. The book addresses personal and community responsibilities and includes guidance on body cleanliness, sexual health behaviors, and protection against communicable diseases, including isolation of people with leprosy. You may remember hearing about leper colonies back in history.

So over the last few decades we've had tremendous movement in tobacco legislation. Laws prohibiting smoking in workplaces, restaurants, and other public places have been passed to encourage smokers to quit while protecting non-smokers from the effects of secondhand smoke. Additionally, increases in cigarette taxes have been shown to be a deterrent to cigarette purchases. And you've probably heard the term obesity in the news. About 60 million Americans (nearly one-third of all adults) and about one in five children are obese. And doctors typically define obesity as a condition in which a person's weight is 20% or more above normal weight or as a body mass index of 30 or higher.

Policies and laws related to food labeling, physical education minutes and resources for children in schools, and even access to healthy foods and safe places for physical activity in communities. These are all examples of prevention through policies that can impact obesity in a positive way. To summarize this section of the course, we work in public health to prevent epidemics and the spread of disease and injury, protect against environmental hazards, promote and encourage healthy behaviors, and respond to disasters and outbreaks. Alright. It's time for another knowledge test. Which of the following events in public health history have been pandemics?

And just one clue. There is more than one answer. Also remember that pandemics are not the same as epidemics. So the correct answers are B and C. Both influenza and polio are examples of pandemics in the history of public health. Now let's talk about public health in a broader context. As we have seen, public health problems are diverse. They include infectious diseases, chronic diseases, emergencies, injuries, environmental health problems, as well as a multitude of other health threats. However, regardless of the topic, we take the same approach to a public health problem by following four general steps.

First we ask what is the problem? In public health, we identify the problem by using surveillance systems to survey and monitor health events and behaviors among a population. And after having identified the problem, the next question is: what is the cause of the problem? For example, are there risk factors that certain populations may have that make them more susceptible to diseases? Maybe it's something inthe environment or certain behaviors that people practice. Once we have identified the risk factors related to the problem we ask, well, what intervention works to address the problem? We look at what worked in the past.

Perhaps when addressing the same problem with different populations we seek to see if something might work with our population, and we seek to see if a proposed intervention would make sense with our affected population. In the last step we ask ourselves, how can we implement the intervention? Given the resources we have and what we know about the affected population, will this intervention work? And this is a very simplified approach. Each of these steps can be broken down into more specific activities, but they are really just the general questions that must be answered to identify a response to a public health problem.

Surveillance, identification of risk factors, evaluation and implementation of interventions. Now, to implement the public health approach, professionals use and apply scientific methods that come from a series of basic courses. These sciences include public health surveillance, which we use to monitor a public health situation, and epidemiology allows us to determine where diseases originate, how or why they move through populations, how they spread, and how we can prevent them. Public health laboratories play a very important role in supporting public health by performing tests to confirm the diagnosis of diseases. And labs also support public health by conducting research and training valuable to the field.

As far as informatics is concerned, as we continue to move from the use of paper documents to electronic medical records, public health informatics continues to gain importance. Informatics deals with methods of collecting, compiling, and presenting health information and allows us to use electronic data effectively in addressing a public health problem. And finally, the effectiveness of prevention. This is closely related to public health policy. Prevention effectiveness studies provide important economic information to decision makers to help them compare interventions and then choose one to implement. So together, these five fundamental sciences can help us protect and promote public health by giving public health professionals the answers they need.

Public health is in a better position to respond to a given situation or problem using the contributions of each of these sciences. So let's take a look at the public health approach and how it can be applied to a historical example of an infectious disease. During the 19th century in London, cholera, an often fatal intestinal disease, was widespread, killing thousands of people within hours, sometimes of the first symptoms. So at that time, and this was before bacteria and viruses were recognized as the cause of many diseases and illnesses, popular opinion held that cholera was caused by contaminated air from decaying organic matter.

This became known as miasma or miasma theory. John Snow, a British doctor at the time, had a different opinion about cholera. He believed the disease was spreading through a contaminated water supply because sewage was routinely dumped into the River Thames and into cesspools near the city's wells. Because of his work tracing the path of the cholera outbreak, Dr. Snow is often considered the father of modern epidemiology, and his research changed the way we view diseases today. So let's apply the public health approach to Dr. Snow's investigation into the cholera outbreak. This is a slide of a London neighborhood, and as you remember, we first need to identify the public health problem.

Snow carried out public health surveillance looking at where people with cholera lived in London and saw that large clusters of cases were occurring in specific areas. Then you will notice the red circle and you will see that there are more black dots in that circle and that they represent cases of cholera. So, as you will notice, the concentration of cholera cases is concentrated in the Broad area. The street and the black dots represent deaths from cholera. Note the higher density of deaths around Broad Street. Snow was helped at the time by a local clergyman named Reverend Henry Whitehead.

He was very, very familiar with the neighborhood and the people who lived there. So together, working separately but then their efforts combined, they were able to locate and interview surviving cholera victims and their families and geographically map the outbreak. And their efforts highlight the benefit of linking scientific research with community stakeholder engagement to build shared ownership of health. Next, Dr. Snow examined the data and tried to identify risk factors. He then tried to determine the cause of the deaths using the pattern of where the cases occurred. This slide illustrates the location of water pumps in the neighborhood.

These are the black boxes. So, based on his previous work, Snow believed that water was a potential source of cholera. The map then reveals that the greatest number of cases occurred in areas close to the water pumps, and this observation led Dr. Snow to further investigate the distribution of water pumps in London. And he identified where people who had cholera got water from. His findings showed that clusters of cholera cases were most commonly located around certain bombs, particularly the bomb on Broad Street, right in the center of that graph. So through this research, Dr. Snow concluded that drawing water from the Broad Street pump was a major risk factor for getting cholera.

So, after identifying probable risk factors, the next step in the public health approach is to evaluate possible interventions. With the water supply from the Broad Street pump identified as the risk factor, Snow worked to identify interventions to address the problem. He did a lot of ongoing research and from that research he understood that the interventions needed to control the cholera outbreak were basically two different interventions. One was to stop exposure to the contaminated water supply in the neighborhood and then, on a larger scale, stop exposure to the entire contaminated water supply in the area. So, using the final step of the public health approach, Snow implemented the intervention by removing the handle from the Broad Street pump.

And that prevented people from getting water from that pump because, again, he believed that the water supply was the source of the contamination. That was a pretty simple but brilliant way to effectively stop your exposure to the contaminated water supply. And then, after a very long battle with politicians and the area's water companies, Dr. Snow finally convinced the British government that water contaminated with sewage, and not the smell or bad air coming from the waste itself, was the water. that was the source of cholera and other diseases. So this resulted in the implementation of policies and laws for water sanitation, and that was an intervention on a much larger scale than simply eliminating the threat of a single water pump.

But both interventions had their importance. Alright. It's time for another knowledge test. So this knowledge check just asks you to fill in the blanks with the correct answers. Each core science of public health helps us make public health white and white by giving public health professionals the answers they need. Then I'll give you a hint. Both answers begin with P. The fundamental sciences of public health help us protect and promote public health. But if it had something remotely close to protect and promote, we'll count it as correct. So with this knowledge check, this one matches. And simply relate each component of the public health approach to the questions they answer.

Again, when we ask what the problem is, we are basically talking about surveillance. When we ask what the cause is, we look at determining risk factors. And then we want to know, well, what's going to work? What will help solve this public health problem? That's when we look at intervention evaluations. Possible interventions that we could implement with our particular population. And finally, by process of elimination, how is it done? And that's where you basically decide what you're going to implement. So, this section of the course presents the basic functions and essential services of public health. In 1988, the Institute of Medicine defined three core functions of public health agencies that must be carried out at all levels of government for the overall public health system to function effectively.

The three main functions are evaluation, policy development and assurance. So evaluation is knowing what to do and is based on data collection and analysis. You must have data before you can do anything else. Policy development is much broader than legislation. It can be guidelines, standard operating procedures, laws, rules, regulations... all of these are covered by policy development. And policy development is based on the information that comes from the evaluation function and provides for the use of that information in decision and policy making. Assurance is ensuring that policies and programs are implemented providing public health services to those who need them.

So if you reflect briefly on the mission statement that we discussed earlier of the Institute of Medicine, that public health is ensuring conditions in which people can be healthy, that's what this core function is all about. In this graph, the three main functions are on the outside of the circle. You'll see that the assessment at the top right leads to policy development below and then to assurance on the other side. The 10 essential public health services are grouped under these three basic functions. These services are not a recipe for what public health agencies should do, but are actually intended to capture the field of public health and communicate what it offers.

The strength of a public health system lies in its ability to effectively deliver the ten essential public health services. So, using the theme of tobacco prevention, let's explore how essential services can be implemented. Under the evaluation function, what are examples of number one, monitoring health for prevention of tobacco use? An example is monitoring the health of segments of the population. For example, youth. Another example could be monitoring global tobacco prevention by country. Second, public health investigates the risk factors associated with tobacco use, such as the risk of developing a certain type of cancer. Assessing the problem provides more data to inform policy development, and that is the second central function, as you may remember, of public health.

And that's, again, on the outside of the circle at the bottom right. The third essential service, which is under policy development, is to inform, educate and empower people about health issues. So think about different ways you learn about the dangers of using tobacco. Do you hear it from your doctor? So you see PSAs maybe in magazines? So those are all examples. People need to be informed and educated before they are allowed to make changes, such as quitting or never starting to use tobacco. On a larger scale, empowerment leads to community mobilization, which is number four. This could include advocacy groups working to build support around banning smoking in restaurants.

And that leads to number five, where policymakers then develop policies to do that work, to achieve that work. So what other policies related to tobacco prevention can you think of? Often people might say, well, raise taxes on tobacco or don't sell tobacco products to people under a certain age. Have a minimum age requirement and enforce it in retail establishments. And those are all great examples of policies. Once policies are enacted, they need to be enforced to have an impact. If they are not applied, they are of no use. So law enforcement is the sixth of the essential public health services.

And using our example, this could be fining someone for smoking on an airplane because smoking is not allowed on airplanes under federal law. Number seven is linking people to necessary public health services. Thus, an example would be referring smokers to smoking cessation lines or receiving advice so that they can stop smoking. Eighth, we mustEnsure that competent public health personnel are available to help people quit smoking. And for all the interventions we develop, it is essential to evaluate their effectiveness, both during and at the end. And this is number nine. So we ask ourselves: did the anti-smoking campaign do what it was supposed to do?

Did the smoking cessation program achieve its intended objectives? How successful was the policy we implemented to increase tobacco taxes? Did it discourage people from buying cigarettes and therefore help them quit smoking? That is why evaluation is essential throughout the process. The essential services of enforcing laws, linking to care, ensuring a competent workforce, and assessment all fall within that core assurance function on the left side of the circle. And as you remember, guarantee is guaranteeing the provision of services to those who need them. Now you will notice that in the middle of this graph there are investigations.

So research is in the middle of all of these core functions and essential services because it continually informs everything. So think that as new tobacco products are developed and new things are constantly coming out, CDC laboratories continually conduct research on these new products to help us discover their possible negative health effects and help us analyze new products that are marketed or sold and how we could combat them and fight the tobacco industry. An important point about these essential services is that while they are displayed on a very nice graph and occur in sequential order, in reality they do not always occur that way.

You might have it where you're doing a couple of essential services and then you can skip it or you can skip a couple of essential services and move on to a different one. Sometimes things just aren't packaged right. Sometimes it is possible to perform some services and then go back and perform them again. And again, with new research continually informing everything, that again prevents a good chronological and sequential flow. But if we look at this in sequential order, it makes sense that we start with health monitoring and then work our way up to ensuring a competent workforce to carry out the interventions we have decided to implement. implement to achieve better health of the population.

Therefore, the core functions of evaluation, policy development and assurance must be carried out at all levels of government for the public health system to function effectively. And this slide shows the central functions at the top and the three different levels of government on the left. So I'll go through each level of government and give you the example of evaluation, policy development, and assurance. Thus, at the federal level, an example of an evaluation would be conducting national public health surveillance in relation to tobacco. And then one policy, as we have already mentioned, is that they have banned smoking on commercial airline flights.

And then the security is that the federal government, like the CDC, provides federal grants for anti-smoking research and tobacco use prevention, cessation and control. At the state level, states also control tobacco use. States have autonomy to increase tobacco taxes. If you look at all the states, there are many different types of tobacco taxes. They are not all the same amount. It is entirely up to the states to regulate it. And lastly, security. An example of that might be an estate that has a proposition, like Proposition 99, I think it was in California, that funds campaigns to prevent smoking.

At the local level, local communities also report tobacco use. That's one way they do assessments to collect data and diagnose. Then that moves, again, to policy development. There are county laws prohibiting smoking in bars and restaurants. Maybe in your county those are good things. And then assurance, at the last level, an example of that at the local level is resources that the county or a local health department could develop to help people quit smoking. And they could put those resources in different languages ​​that are representative of the populations of people who live in those communities. Again, there are very different levels, but each level has to have a function for all of these functions and services to work together and be successful.

Alright. So this brings us to a knowledge check. Which of the following is not a central function of public health? And I hope everyone got it right. The correct answer is authority. Therefore, assurance evaluation and policy development are functions of public health. So here's a second knowledge check. Essential health services of health monitoring and disease diagnosis and investigation are related to which basic public health function? Is it assurance, evaluation or policy development? And remember, it's about learning more about the health problem, and that's done through assessment. And you have to do that before you can do anything else in a meaningful way.

So the next section of this course is about the roles of different groups that have an interest in public health. The field of public health requires actors with skills and intervention programs, policies, research, education, etc. Partners include governments, community groups, clinical care providers, employers and businesses, the media and academia. I could go on and on, but those are the main groups, at least what this slide shows, plus the infrastructure provided by the government at all levels, as we just covered. So what other sectors and fields can you think of that have an interest in public health?

When I talk about this with other groups, some of the answers I get are transportation, housing, schools, urban planning, law enforcement, and religious institutions. I mean, those are all great examples of other partners who have an interest in public health. And some of them are considered non-traditional partners, but our hope is that they become more traditional and people don't just think about providing healthcare, for example. Or that, basically, we realize that there is an approach to health and all policies, which I will get to in a moment. Non-governmental organizations, often called NGOs, play a key role in public health, especially at the community level.

NGOs serve many different purposes, from advocacy or education to emergency relief and economic development. Types of NGOs include professional membership organizations, groups that focus on a specific health issue, citizen groups, advocacy groups, and foundations that support health projects and work at the policy level. So the right column only shows one example of each of these types of organizations. Along with public health, healthcare plays a vital role in protecting and promoting people's health. So while the functions of public health and healthcare are complementary, there are differences shown on this slide. Public health, as we have discussed before, focuses on populations, while healthcare focuses on the individual patient, which is reflected in different guiding ethics for both areas.

Public health focuses on prevention. And while health care deals with prevention to some extent, its primary focus is more on diagnosing and treating the problem. Each type of laboratory works together, but public health interacts with the field on behalf of groups of people. And clinical laboratories work with healthcare providers on behalf of individual patients. And the last row of the table shows that, although the clinical sciences are of peripheral importance to public health, they are essential to the clinical training of health care providers. These are some of the other major partners in public health. Today we are seeing the role of social media as a vehicle for public discourse on all issues, including public health concerns.

Whereas, historically, it was more public health agencies and other partners who educated the public and promoted healthy behaviors through news and entertainment media. But now there is more self-promotion and social media continues to take off. Employers and companies, obviously. They contribute to public health by providing health insurance. Workplaces also have wellness initiatives, such as subsidies for gyms or on-site exercise facilities, that can promote the health of their employees. Government agencies, such as the CDC, work in partnership with state, local, and tribal health departments. However, other government agencies at all levels make important contributions. Urban planning departments can include sidewalks and bike lanes to promote and support safe places for people to be physically active.

Education departments can ensure healthy food options in schools and in vending machines. Similarly, many other government agencies work as partners in public health by including health considerations in the development of their policies, and this is known as a health and all policies approach. There's just this concept that whatever you do as you plan, think about how it can impact public health. And that's what I was referring to before. It says health and all policies. And really, that opens up the opportunity for public health to partner with a variety - there really are an infinite number of different types of organizations.

And last but not least, academia educates and trains public health personnel and conducts research that informs public health and provides a great service to the field. So we have another comparison exercise for this knowledge check. It is necessary to match each actor with their role in public health. So, as a vehicle for public health discourse, the correct answer is the media. Newspapers, opinion editorials, social networks, all media. Health in all policies, as I said, is something that the government can definitely play an active role in, as can other organizations. But for the purposes of this knowledge check, the correct answer is C, government.

Education and training are things that academia contributes to public health. And the stakeholder that delivers employee benefits and wellness initiatives are employers and businesses. So, the last section of this course covers the determinants of health and explains how they affect public health. As we mentioned previously, certain factors determine a person's state of health. Scientists generally recognize the same general categories of health determinants for any population, and these are genes and biology, health behaviors, social characteristics, and health services or medical care. So I'd like you to think about some examples of each of these broad categories. What are some examples of genes and biology?

We might think about a person's sex, age, or immunity levels. For health behaviors it could be whether a person is a smoker or not. What are that person's eating habits? Whether or not a person takes prescription medications for a chronic condition they have. Social or social characteristics. They can include a person's ability to work, the quality of schools, where a person lives. What is the quality of air, water and sanitation in that person's immediate neighborhood? And then examples of healthcare are insurance coverage and even proximity to getting quality healthcare. This graph is an estimate of how these four main categories of health determinants influence health at the population level.

The graph shows that healthcare is not the primary factor determining our health, but it represents a substantial portion of the United States budget. Most of what determines our health at the population level are social characteristics, while genes and biology have the least influence. And then health behaviors, again, in a pretty substantial amount. But it is actually the social characteristics and ecology, including the person's environment, that have the greatest impact. To address the determinants of health on this slide we just discussed, we need to have a plan of attack. A means to effect change. The health impact pyramid describes this plan.

Shows the impact of different types of public health interventions. So, as we go down the pyramid, the public health impact increases, and as we go up the pyramid, the amount of individual effort to achieve the impact increases. So let's start at the top. When we start at the top and work our way down, we can provide advice and education. We can provide direct clinical care andkeep going. We can then provide clinical interventions that require more limited contact but confer long-term protection. That's what preventative medicine does. We can change the context to make individual default decisions the easy ones but the healthiest ones.

And at the base of the pyramid, the socioeconomic determinants of health are addressed. Interventions focused on the lower level of the pyramid tend to be more effective because they reach broader segments of society and require less individual effort. This is not to say that what is at the top of the pyramid is not important because it is, but implementing interventions at all levels of the pyramid is what will achieve the maximum possible sustained public health benefit. And a point to note here too is that there are trade-offs. Sometimes we have to give up resources in one area to have a greater impact in another.

But let's look at some examples of each level of intervention. The pyramid then illustrates the impact of different types of public health interventions. And again, moving from the top down. Counseling and education in clinical and public health settings are considered by some to be the essence of public health action. I went to school and actually majored in health education and promotion when I got my master's degree in public health. But being at the CDC, I've learned a lot about how all of those other areas, including the bottom area, really have a substantial impact on interventions. But that, again, is not that counseling and education are not as effective as we would like.

But that being said, there are times when counseling and education are the only forms of intervention available or appropriate. And when applied consistently and repeatedly, they can have a positive impact. So moving on to clinical interventions, one example is ongoing medical care for a health condition. For example, in the case of cardiovascular diseases, these interventions can have a considerable effect. But we are also limited by the lack of access to certain patients who need that type of care and the failure to follow medical instructions and take prescriptions as prescribed in the real world. Again, such medical care has its limitations.

So in the middle of the pyramid, looking at the level of preventive medicine intervention, let's talk about vaccines as an example. Vaccines prevent 2.5 million deaths among children worldwide every year. So in this case, a single dose or intervention can have a lifelong effect. This is an example of a long-lasting preventive medicine intervention. The next level of the pyramid is where we make default decisions by changing the context in which behaviors occur. And it makes it more difficult to avoid intervention. For example, changing laws to require seat belt use. Making it easier for people to wear the seat belt because if you don't put it on, you hear a really annoying beep until you put it on, so you want to put it on and just make the noise go away.

But it's much easier than before to wear a seat belt. Another example is the ban on smoking in certain public places. Both examples and achievements in public health have had a tremendous impact and saved many, many, many lives. In another basic example, some of the CDC buildings (the newer buildings, for example) when you first walk in, the stairs are what you see before you see the elevator. And the stairs have windows and maybe have some plants or some music. That makes it much more pleasant and very easy for people to decide to take the stairs instead of going around the corner to find the elevator.

So that's a real basic example of making healthy default choices. At the base of the pyramid are public health interventions that affect socioeconomic factors. If we can improve the quality of life by helping people escape poverty, providing basic health services, improving access to education, helping them get jobs, providing healthy food and health care, we can greatly improve the health of the population. So it's time for another knowledge check and I'd like you to list just four determinants of health. Now remember, it can be genes and biology, health behaviors, social characteristics, and health services or healthcare. In our final knowledge check of the course, simply fill in the blanks using the two options.

First, as we go down the health impact pyramid, the public health impact increases. Remember, the base of the pyramid is the socioeconomic factors. As we move up the pyramid, the impact on health becomes greater in terms of the amount of individual effort required. Again, all levels of the pyramid are important, but it's just a good framework for thinking about how interventions can be implemented at different levels. Within each of the topics we have covered in this course, underlying all our actions and decisions is the application of the basic sciences of public health. I encourage you to take advantage of this introduction to public health by learning more about these fundamental sciences and how they contribute to the field of public health.

Let's review the learning objectives for this session. The course provided content to help you describe the purpose of public health and define some key terms used in public health. You will remember that we talked about epidemics and determinants of health. The course helped him identify notable events in the history of public health. That's where we look at some historical highlights of public health through sanitation and environmental health, pandemics, disaster preparedness and response, and prevention through policy. The course helped him recognize the basic functions of public health (those three functions) and 10 essential services. You should be able to describe the role of different stakeholders in the field of public health, as well as list some of the determinants of health.

And finally, it must be recognized how individual determinants of health affect the health of the population. Thank you for your attention today for the introduction to public health. To receive continuing education units, CEU credits, for today's webinar, complete the webinar assessment in CDC TRAIN by logging in and searching My Learning. If you or one of your colleagues were unable to attend today's webinar, an archived version of this webinar will be available on CDC TRAIN in approximately two to three weeks. For more information about CDC webinars, visit www.cdc.gov/labtraining. Thank you again for participating in today's webinar.

Have a positive and healthy afternoon.