1c. What is Population Health?

Population health aims to improve the health of the entire population and to reduce health inequities among population groups. In order to achieve these objectives, it focuses at and acts upon the broad range of factors and conditions that have a strong influence on our population health status. Accordingly, action is directed at the health of an entire population, or sub-population, rather than at individuals.¹

For more information about the population health approach, including the key principles of population health and a historical overview of the development of population health in Canada, review “ What is a Population Health Approach,”  developed by the Public Health Agency of Canada.¹

The following video, developed by the Children’s Hospital of Colorado, takes a population health perspective on child obesity and underscores the need for more “upstream” population-level interventions to address this issue. 

What Is a Population Health Intervention?

The focus of this course is on helping you to think about, design, select, and monitor interventions that may be useful for improving population health, especially as it relates to the prevention of chronic disease.

So, now that you understand the meaning and origins of population health, the next logical topic to address is what we mean by the term intervention. The Oxford dictionary defines the word intervene as “to take part in something so as to prevent or alter a result or course of events”.² By extension, therefore, a health intervention may be defined as “taking part in something” through actions intended to prevent or modify health, illness, death, disability, or their determinants. To be completely correct, most of the time we cannot directly modify health or illness. Rather, we must satisfy ourselves by altering measures that are intended to measure or indicate health status, illness, disability, death, or their determinants. Even death is subject to this caveat. That is, it is convenient for us to define death according to a series of measures or indicators such as loss of brain wave activity or a sustained loss of an ability to produce a heartbeat.

Categories of Population Health Interventions

In general, health promotion and disease prevention interventions may be grouped into four broad categories. I’m not going to provide a lot of information on these categories now, as subsequent modules address them in greater detail. But the following information will give you a better understanding of the practical solutions available to public health practitioners to address population-level health issues.

1. Treatment Services or Programs

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The first category most people think about involves the delivery of a treatment through a service or program. This might include counselling for smoking cessation, dietary counselling, mammography, or genetic screening.

We can classify treatment services according to who delivers them. For example, services are often provided through primary care, the “big P” Public Health system, long-term care centres, etc. However, in some instances, treatments can be provided through the voluntary or non-profit system or the private sector.

We can also sub-classify treatments according to the way they are delivered. The content may be delivered via self-help books, websites, by telephone, or in person. Finally, treatments may be aimed at individuals, couples, groups, workplaces, schools, neighbourhoods, or an entire country.

2. Healthy Public Policies

Natural Resources Canada Office of Energy Efficiency (2010, Dec. 7). [Idle Free Zone Street Sign]. Retrieved from http://oee.nrcan.gc.ca/transportation/idling/material/campaign-resources.cfm?attr=28

A second form of intervention, especially for public health, is the development, implementation, and monitoring of healthy public policy.

Healthy public policies promote the health of individuals and communities by

1. making it easier for people to adopt healthy practices;

2. making it harder for people to adopt unhealthy practices; and

3. creating healthy physical and social environments.³ 

A policy can be private, proprietary, or public. For example, someone can implement a private or personal policy within their home such as the last person to bed should lock the doors. Workplaces can implement proprietary policies. Public policies are those enacted by and generally through one or more levels of government.

Public policies can be quite specific or very broad. For example, a public policy and legislation might be written to lay out the conditions and responsibilities for a single person such as a medical officer of health. On the other hand, it can be a policy to regulate industrial emissions into the air that affects large populations.

Broadly speaking, healthy public policies fall into one of three categories, although there is some degree of overlap between them, and they are often used in combination.

1. Regulation refers to legislated rules or directives that encourage the performance of healthy behaviours, such as wearing seatbelts. Regulations such as the minimum wage also affect population-level access to the social determinants of health such as food and shelter.

2. Taxation, the levying of tax on income or products, is arguably the most powerful policy lever for influencing health at the population level. For example, research shows that a 10% increase in tobacco prices decreases consumption by about 4%.⁴

3. Fiscal Measures determine the amount of money allocated to the resources needed to maintain good health, including the social determinants of health, such as income support, education, and public transportation. As such, fiscal measures are an important consideration for healthy public policy.

3. Community Mobilization  

The third population-level strategy is community mobilization, which is sometimes referred to as community development. If I asked you to identify your “community,” you might respond by naming the city, town, or neighbourhood where you live. But geography is not the only way of defining a community. Communities can also evolve from a group of people with shared interests or characteristics, such as ethnicity, occupational status, or sexual orientation.⁵

The most important defining characteristic of a “community” is a shared sense of affiliation or “belonging” among its members. When identifying a community for the purposes of taking action on a health issue, it is important to note that individuals do not belong to just one single, distinct community. Most people maintain membership in a range of communities formed around variables such as geography, occupation, social, and leisure interests.⁶

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Community mobilization involves empowering and organizing people in a way that will enable them to define their shared health issues of concern and take action. As I noted previously, we will be spending more time discussing community mobilization for population health issues in a later module.

4. Health Communication and Education

GetSomeCondoms (2011, Nov. 21). [Heads Up?! Use a Condom poster]. Retrieved from https://www.facebook.com/259618414073402/photos/a.265912430110667.57198.259618414073402/277503802284863

The fourth and final type of intervention relevant to public health is health communication and education campaigns. Essentially, these involve the dissemination of messages designed to influence the knowledge, beliefs, confidence, or attitudes of individuals or large groups.

• Communication campaigns are typically designed to alter the behaviour of large numbers of people rather than a handful of people, one person at a time. ⁷

• Health education can be a treatment strategy when it is delivered in a limited setting by a physician or nurse to a single individual. However, health education systematically delivered through classrooms in schools is intended to affect mass audiences. The distinction between treatment and communication is one of convenience rather than of absolutes because something like getting all family doctors to counsel their patients about smoking or diet may be classified as either a communication strategy or a treatment service that is systematically applied.

There are numerous examples of communications campaigns addressing population health issues: campaigns designed to reduce driving after drinking, encourage the use of condoms to reduce sexually transmitted infections, encourage people to eat at least five servings of fruit and vegetables per day, or change public attitudes about homelessness are some that come to mind. We will spend more time later in the course discussing how to create effective messages and campaigns through the use of various models and techniques. 

Population Health Interventions

The final topic I want to address in this section are the conditions necessary to justify a population health intervention. If we can demonstrate the following six conditions, then a systematic attempt to change behaviour or social condition through some form of population health intervention is justified. 

1. We must be able to show with reasonable certainly that behaviour or social conditions can influence health in a predictable way.

2. We must demonstrate that people can change their behaviour or that the social conditions contributing to unhealthy behaviour can be changed. If they can’t change, what is the point in trying to change them?

3. We must show that changing behaviour can ameliorate or reduce the excess health risk associated with that behaviour or social condition. What is the point in changing a behaviour or condition if the level of excess risk of a negative outcome or odds of a positive outcome doesn’t change?

4. We must demonstrate that what we do as public health practitioners would not have happened or happened to the same extent or with the same speed if we hadn’t done anything (as you will see in a later module, population level interventions are generally more difficult to assess for a variety of reasons).

5. There is no point in developing effective interventions if they are unethical or unacceptable to people: implementation will either not happen or not be effective. We must demonstrate that the potential benefits of any population health intervention outweigh the potential risks.

6. Finally, and of greatest importance, we must demonstrate that our intervention (or combination of interventions) is more effective than alternative approaches to addressing the population health issue in question.