What does it mean? When did it begin? How is it different from public health? Here are the answers to these questions and more.
The provenance of healthcare terminology is often difficult to pinpoint. Like success, jargon with staying power tends to have many parents.
So it is with “population health.” A Pubmed search shows the term was in the title of a paper on land monopoly in 1890, and it starts popping up in epidemiologic research titles in the 1970s. But some say it only really entered the healthcare vernacular in 2003, when David Kindig, M.D., Ph.D., of the University of Wisconsin and Greg Stoddart, Ph.D., of McMaster University Health Sciences Centre in Canada published a paper titled, “What is Population Health?” in the American Journal of Public Health.
Jaan Sidorov, M.D., CEO and president of PA Clinical Network, a clinically integrated network for independent practices in Pennsylvania, credits David B. Nash, M.D., MBA, with coining the term in an article he cowrote with Janice Clark. Nash, who founded the Jefferson College of Population Health, part of Thomas Jefferson University in Philadelphia in 2008, bridged the transition from “disease management” to “population health” with “population-based disease management,” says Sidorov. But the real credit for the term gaining currency belongs to the Congressional Budget Office and its 2004 report on disease management that questioned whether population health reduces costs, according to Sidorov. “A new approach was clearly needed and a new name emerged.”
Feeds on data
However, coining a term is one thing, assigning it a meaning is another. The question Kindig and Stoddart asked still gets asked, and answered in a variety of ways. Kindig and Stoddart were nice and succinct in their definition: “The health outcomes of a group of individuals including the distribution of such outcomes within the group.” The CDC, which has a Division of Population Health, is far wordier and gives more of a functional definition. Population health isinterdisciplinary, according to the CDC website, and an approach that uses “nontraditional partnerships” among different sectors of the community — public health, industry, academia, healthcare, local government entities — to achieve positive health outcomes.
Either way, population health dines on data, lots and lots of data. “Population health relies heavily on information technology to manage, cross-reference and analyze huge amounts of data to provide actionable reports,” observes Mitchell A. Kaminski, M.D., MBA, an associate professor and program director of population health at Jefferson College of Population Health.
Typically, population health depends on two major sources of data: a wide range of government data and clinical and claims data generated by healthcare providers and payers. The trick is often figuring out ways to bring them together. For example, a health system may want to reduce hospitalizations and deaths in patients with asthma. Its data can identify which patients have asthma and which of those have gone to the emergency department or been hospitalized. The data will also include information about prescriptions and refills that can lend insight into whether adherence played a role in those emergency department visits and hospitalizations. Data from government at the federal, state and local level can indicate whether environmental factors that may have triggered asthma are nearby. Similarly, assessing all those now-familiar social determinants of health — housing, nutrition, education and public safety — requires data that often come from public and government sources. “A hospital or medical practice won’t be able to reduce asthma hospitalizations and deaths unless it has the data to reach out and partner with community agencies to address major contributing factors,” Kaminski says.
Katrina Miller Parrish, M.D., chief quality and information executive at L.A. Care Health Plan, a publicly operated health plan in Los Angeles, points out the differences between healthcare on an individual, person-by-person basis and the population health approach. A clinician would ask an individual, “How are you feeling and are you taking your medications?” and then address that patient’s issues. They may be forgetful about taking their pills and need some advice about establishing a routine. Maybe price is a concern and less expensive alternatives can be prescribed. Adherence viewed through the lens of population health involves looking at data for patterns of use and ways to address them in a systematic way across a group of patients. Perhaps the data would reveal that a subset of patients need particular attention and that sifting through the data would show why they are not taking their medications as prescribed.
Emily Hajjar, Pharm.D., M.S., program director of the population health pharmacy program at Jefferson College of Pharmacy at Thomas Jefferson University, says that population health data are anchored in dealing with the determinants of health: “We know that some people are considered to be healthy and others suffer from poor health, so population health explores what factors contribute to health and wellness and what factors predispose others to poor health outcomes,” she says. Kindig and Stoddart discussed determinants in their definitional manifesto 17 years ago. “We support the idea that a hallmark of the field of population health (the emphasis is theirs) is significant attention to the multiple determinants of such health outcomes, however measured,” they wrote, adding a long list of determinants that range from medical care to the “social environment” (income, education, culture) to the physical environment, which includes air and water quality. Hajjar says the potential for efficiency is one advantage of a population health approach: instead of assessing patients one by one and devising individual solutions for their problems, population health can tackle common problems in a systematic way. “This is not to say that individuals are subjected to cookbook medicine,” she notes, “but focusing initiatives on certain populations can create care pathways that allow patients to receive a similar level of care for specific diagnoses to increase consistency and reduce inequities.”
Population health data can also be used to inform and shape policy changes, says Shunling Tsang, M.D., M.P.H., the medical director of ambulatory quality and vice chair of the Department of Family Medicine at Riverside University Health System in Riverside County, California, east of Los Angeles. The quality metrics that affect payment rates to healthcare providers are rooted in population health data, for example. But that data may also factor into decisions that are well beyond the normal boundaries of healthcare, such as the city’s decision on where to build a new park or construct a bike path to make it easier and safer for people to become physically active.
Joseph M. Geskey, D.O., MBA, M.S.-PopH, a principal at Vizient, points to research that suggests that only a relatively small proportion, as small as 20% according to one study, of the modifiable contributors to health outcomes involves clinical care. “Therefore, in order to improve the overall health of a population (which is more expansive than just clinical care), we have to holistically understand what influences health outcomes,” he says.
Many see population health and value-based care as linked, indeed, joined at the hip. In broad strokes, value-based care involves payers, both public and private, paying providers such as hospitals and clinicians according to the value (outcomes divided by cost) of the care delivered, not the volume. Looking at outcomes for a set of patients is seeing healthcare in a population health framework.
Another manifestation of the population health mindset are the dashboards an increasing number of clinicians are using to analyze data about their patients and manage their care. They are also used to compare practice patterns and to nudge (to put it mildly) outliers back into the mainstream. A dashboard might, for example, show the proportion of a provider’s patients who have been vaccinated against the flu. Such ratios are the stuff of population health.
No, not public health
Population health and public health are, understandably, confused and conflated and sometimes used interchangeably. But at the risk of being overly fastidious, and with the benefits that come with clear definitions, they should be kept separate. Public health is more expansive and focuses on what society does collectively to ensure that people have the appropriate conditions to be healthy, says Vincent Nelson, M.D., MBA, vice president of medical affairs for the Blue Cross Blue Shield Association in Chicago. It focuses mainly on policy recommendations, health education, outreach and research. In comparison, says Nelson, population health focuses on how different groups, agencies and organizations work together to improve health outcomes in communities.
Social determinants of health is a phrase that often comes up in discussions of public health and population health. Both grapple with the social determinants of health, such as housing and nutrition, but they are not themselves social determinants of health.
American healthcare is subject to fads and trendy phrases and words used more for effect than substance. But it has been almost 20 years since population health nosed its way into American healthcare, and it has demonstrated staying power, as a term and as a way of thinking about and managing healthcare. “This field of study has developed exponentially in recent decades; we’re refining the state and needs of populations far better than we ever have,” says Parrish of L.A. Care Health Plan. She invoked the Triple Aim, the formulation that healthcare should have as its goal of improving the experience of care, reducing per capita cost as well as population health.“Since the third aim of the Triple Aim is reducing per capita cost, the more we can target appropriate education, prevention and treatment to the right population who needs it, the more efficient and equitable we will be with resources.”
Geskey believes that employing population health data is the only conceivable way to reduce racial inequities in care and improve the large discrepancy that exists in health outcomes between the U.S. and other advanced countries. “Employing this data would save money that can be reinvested in the economy and allow the United States to remain competitive with other countries to create desirable, well-paying jobs in the future,” he says. “This is especially true if the government refuses to use its leverage, scope and power to ensure that healthcare is a right of all U.S. citizens and set a global budget that is allocated to healthcare.”
Kimberly Zeigler, MBA, director of population health and analytics at Sonora Quest Laboratories, a joint venture of Banner Health and Quest Diagnostics in Tempe, Arizona, believes that population health will continue to benefit from emerging and advancing technologies as well as enhanced methods of data sharing to improve outcomes for members of a population. “The data (are) becoming much more granular and individualized as technologies and data sharing are continuously improving and stakeholders collaborate to improve outcomes or, as we are currently experiencing, (respond) to a pandemic,” she says.
Population health has had staying power partly because it is defined by concepts rather than rigid definitions, Tsang says. Those concepts are flexible enough so that population health can be invoked at a relatively micro level where the issue might be health outcomes for patients in the panel of a particular provider, or at a macro level where the issue might be the health status of residents of a city, state, or country, Tsang observes.
Karen Appold is a medical writer in Pennsylvania.