1.1 Defining Population Health

The Quintuple Aim

Population health can impact numerous specific conditions, diseases, and health risks through interventions that cross disciplines and support a great breadth and depth of positive health change. As a field of study and practice, population health works toward specific aims developed by the Institute for Healthcare Improvement (IHI). In 2007, the IHI developed a framework called the Triple Aim to support optimal performance of the health care system (Berwick et al., 2008). In 2014, the IHI updated the framework to the Quadruple Aim to acknowledge that the health of providers and other health care professionals must be supported to achieve population health goals (Bodenheimer & Sinsky, 2014). Today, the four aims consist of:

1. improving the client experience of care (including quality and satisfaction),
2. improving the health of populations,
3. reducing the per capita cost of health care, and
4. improving the well-being of health care professionals.

Recently, experts have suggested a revision to create the Quintuple Aim, which would include a fifth aim of advancing health equity. In both the fourth and suggested fifth aim expansions, experts have posited that improving population health, client experience, and health cost would be impossible without addressing provider health and burnout or health equity (Bodenheimer & Sinsky, 2014; Nundy et al., 2022). Concepts of the Quintuple Aim can guide evaluations of population health programs and initiatives. For example, telemedicine connects to the goals of improving the health of populations, improving the well-being of health care professionals, and advancing health equity. Its services offer several conveniences to clients and clinicians, such as the flexibility to dial in from home and save on commuting fees. These services also remove barriers to receiving care and increase equity in opportunity for clients to see primary care providers and specialists. This can help reduce inequities and disparities with regard to receiving screenings, diagnoses, and treatments for health conditions, which in turn can help improve population health. Telehealth is a growing initiative across health care globally; please see Care Transition and Coordination Across the Community for more information on telehealth. Recently, one research team determined that pediatric telehealth has advanced pediatric care in general so that it has become a better-performing, more equitable system (Cahan et al., 2020). Whether a population, community, or health system elects to use the version with three, four, or five aims, this framework encourages consideration of the interplay among the different aims and innovative approaches to improving health and health outcomes for the population.

Components of Population Health

Population health takes a comprehensive approach that accounts for the complex dynamics among differences in health status, community resources, personal characteristics, familial circumstances, and other factors that can trigger or aggravate health conditions. By recognizing the complex interplay of these numerous and wide-ranging factors, population health takes a holistic view to promote the well-being of all.

Regardless of the situation or specific factors, a guiding theme of population health is the importance and value of taking proactive rather than reactive approaches to improving health. An analogy to summarize population health involves an overflowing sink. Imagine a kitchen faucet is left running unattended, creating a giant puddle on the floor. Better get a mop! Without population health, much of health care focuses on “mopping the floor” instead of “turning off the faucet” (Kaminski, 2021). In other words, health care as a system largely deals with floods—that is, helping clients who are already sick—instead of turning off the water, or addressing the situations and circumstances that make clients sick in the first place. Health care providers, nurses, policymakers, and the health care system at large should focus on the causes of health problems to prevent them before they occur, instead of focusing primarily on treating diseases as they happen. Of course, clients, families, and communities need access to treatment for their health conditions—but what if there was a way to prevent the conditions from happening in the first place?

Four key health concepts have been essential in advancing population health: outcomes, disparities, determinants, and risk factors.

Outcomes are all possible results. Health outcomes are indicators or data points that reflect the degree to which health interventions, care, policies, and behaviors are effective in supporting the health status of populations. Examples of health outcomes include mortality rates, life expectancy, disability rates, birth rates, health care costs, and health-related quality of life measures. Outcomes may come from exposure to interventions that aim to prevent or treat a condition, or they may result from exposure to health risks or situations detrimental to health. For example, creating a policy that allows people under a certain income level to have free health insurance may produce a range of outcomes, including insuring a greater percentage of the population and increasing the number of people who attend wellness exams—and, consequently, increasing the number of people who smoke who may be offered smoking cessation resources. On the other hand, removing or relaxing policies that prohibit smoking in public places may produce quite a different range of outcomes, including making it more difficult for people to quit smoking, exposing more people to secondhand smoke, and increasing rates of children who start smoking.

Disparities are inequalities or differences. A related concept is health inequities, which are avoidable inequalities related to health that stem from a form of injustice (Kawachi et al., 2002; McCartney et al., 2019). For example, children attending the Lincoln School may have higher rates of asthma than children attending the Washington School. The children are all the same age and have the same racial and ethnic distribution, but the parents of children at the Washington School have a higher average income and donated money so that each classroom could have an air conditioner. There is a disparity in access to clean air, as well as in rates of asthma, between children at these two schools. Health Disparities covers this topic in greater detail.

Determinants are the innumerable factors that influence health and generally include nonmedical events, characteristics, or other entities that change a health condition or the level of a health problem (Kindig, 2007; Office of Disease Prevention and Health Promotion, 2022). Within population health, determinants of interest include medical care, public health interventions, income, education, employment, social support, culture, clean air and water, outdoor space, genetics, and behavior (Kindig, 2007). Determinants can interact with each other to bolster health or worsen a problem (Figure 1.2). For example, when a client is unable to finish high school, they may not qualify for a full-time job that pays a living wage and offers access to a health insurance plan. Such a situation would undoubtedly impact the client’s ability to seek care when needed and to engage in health promotion efforts.

Social determinants of health are additional factors that influence the health of populations, families, and individuals. Social determinants of health are conditions and social factors that affect outcomes and risk related to health, functioning, and quality of life. Conditions or factors in hospitals, clinics, workplaces, homes, towns and cities, schools, and beyond influence health outcomes for the population. Economic stability, education access and quality, health care access and quality, neighborhood and built environment, and social and community context are five domains that shape the social determinants of health (Office of Disease Prevention and Health Promotion, 2022). Please see Social Determinants Affecting Health Outcomes for a comprehensive discussion of social determinants of health.

Risk factors are aspects of personal behaviors, lifestyle choices, exposures, or attributes that generally increase the likelihood of acquiring or the severity of a health condition. Risk factors are similar to determinants but tend to be more specific. Consider respiratory disease determinants and risk factors. Air quality and environmental pollution are determinants of respiratory disease, while smoking is a risk factor for respiratory disease. Some determinants may be risk factors; however, other determinants may reduce health risk.

Figure 1.2 This photo was taken during the 2018 Klondike Fire in Oregon. In addition to threatening human lives and homes, wildfires severely impact air quality, release harmful pollutants, and devastate wildlife and ecosystems. (credit: “Forest road 2512 and smoke-filled air, Klondike Fire” by U.S. Forest Service-Pacific Northwest Region/Flickr, Public Domain)

Additionally, population health focuses on upstream, midstream, and downstream approaches to improve health outcomes (Figure 1.3) (Salmond & Allread, 2019).

• Upstream interventions involve enacting policies that change regulations, increase access, or provide economic incentives to impact health across a population. Examples include policy changes regarding the fast food or tobacco industry, provision of universal health care, and compensation for hospitals with lower inpatient admission rates (Porter et al., 2022).
• Midstream approaches are those that happen within specific organizations. For example, a workplace may provide healthy lunches to employees each day (Porter et al., 2022).
• Downstream interventions focus on the behavior of individual people to modify the risk of disease, prevent illness, or manage chronic conditions (Brownson et al., 2010; Fornili, 2022). For example, a nurse might counsel a client with hypertension about consuming a low-salt diet.

Figure 1.3 Population health involves the complex interactions of upstream, midstream, and downstream interventions. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

These key components interact in complex and evolving ways as population health and the health status of the population change over time. By employing upstream interventions, such as policy changes and universal health care, population health addresses the societal factors that impact the health of the population on a broad scale and ultimately the health of individual clients. Midstream approaches can contribute to fostering healthier environments in diverse settings. Downstream interventions, such as those that focus on individual behavior to support health, are also important in a population health model, as members of the population will never be fully free of health conditions requiring treatment. Together, upstream, midstream, and downstream approaches offer a framework for population health programming and interventions that can create positive health outcomes.

Global Population Health

The need to address the factors and components of population health is a global one, and given the interconnected nature of the health status of people around the world, nurses should prioritize and actively contribute to enhancing global population health in addition to advancing local and national population health programs, goals, and outcomes. Many people around the world face significant challenges to promoting their health, receiving treatments, and reducing health risks. Health outcomes, disparities, determinants, risk factors, and upstream, midstream, and downstream influences are all relevant and crucial to improving global population health. The health status of people as far away as a different continent on other side of the equator can impact the health of clients locally, and nurses have a responsibility to support efforts that advance population health worldwide (Hong & Lee, 2021; Wilson et al., 2016). Nurses have a duty to extend their care, genuine concern, empathy, and compassion to those in need beyond their immediate surroundings. To that end, a global advisory panel on the future of nursing proposed a definition of global nursing:

• Global nursing is the use of evidence-based nursing processes to promote sustainable planetary health and equity for all people. Global nursing considers social determinants of health, [and] includes individual and population-level care, research, education, leadership, advocacy, and policy initiatives. Global nurses engage in ethical practice and demonstrate respect for human dignity, human rights, and cultural diversity. Global nurses engage in a spirit of deliberation and reflection in interdependent partnership with communities and other health care providers. (Wilson et al., 2016, p. 1537)

When nurses engage in global nursing, they can proactively contribute to bettering population health and reducing the global burden of disease, health conditions, disability, and disparities. By embodying a commitment to global nursing, nurses can positively impact and improve the lives of others and uphold the principles of the discipline. Almost any health issue, concern, condition, or topic can be a global population health problem needing solutions.

Vaccines

In the United States, COVID-19 vaccines were available to health care workers and older adults living in long-term care facilities in late 2020 and to the general public in spring 2021. The global population of health care workers, clients, and families did not have the same timely access to vaccines. High-income countries had purchased 54 percent of the world’s available vaccine doses by March 2021, but 81 percent of the global adult population lives in low- and middle-income countries (Stephenson, 2021). Disparities in vaccine access were detrimental to immediate and long-term global population health outcomes and contributed to avoidable deaths. Nurses addressing global population health can advocate for equitable worldwide vaccine distribution, provide education on the importance of vaccination to those who require vaccines and those who determine where vaccine clinics may be located, and provide timely access to vaccine administration (Figure 1.4).

Figure 1.4 A health care worker vaccinates a client in a vaccine clinic in Colombia. The sign in the background reads Vacuna es segura, which means “The vaccine is safe.” Beyond the challenges of quickly developing a vaccine, making enough for the global population, and handling logistics such as transportation and storage, a major barrier to global health in 2021—and to ending the COVID-19 pandemic—was informing the public that the vaccine was safe and effective. (credit: “Colombia COVID-19 Vaccine at Mobile Site” by USAID/Colombia/Flickr, Public Domain)