Population Health Definitions

Population Health Definitions

What is Population Health?

IHI Triple Aim laid the foundation

Population Health (AKA "Pop Health") is in the Health IT news practically every day now. But what do we really mean when we say, Population Health.  Definitions vary. In a nutshell, it is focusing resources on a defined population of people to improve their health and reduce costs.  It's been ten years since Health Affairs published the Dr. Don Berwick's (et al. at the Institute for Healthcare Improvement or IHI) landmark article(1) defining the healthcare Triple Aim. This has provided an important framework on which Pop Health has grown. His paper defined the Triple Aim:

  1. "Improving the experience of care,
  2. Improving the health of  populations, and
  3. Reducing the cost per capita." (1)

At the time, Berwick could individually mention the handful of organizations across the country that embodied the Pop Health concept in their DNA. Today Pop Health is a concept that comprises a lot of theories, practices, processes, tools and technology. There are institutes, organizations and graduate studies in Pop Health. There are hundreds of vendors offering Pop Health solutions.

In Health IT terms, "Beware of Scope Creep." It is important to know the scope of any population health initiative or solution. Many Pop Health solutions address only a small piece of the puzzle. For those looking for an introduction and definition of Population Health, it is helpful to understand how Dr. Berwick and his colleagues laid the foundation for the topic in their 2008 paper.



Photo of a physician planning for a population and icons of the various tools. Population Health definitions include many elements and management tools.
Population health definitions include many processes, tools & technologies.


Why does Population Health matter?

At the onset of the 21st century, most healthcare providers delivered care in a fee for service (FFS) model.  So most were focused on delivery of care to the individual in a specific location (e.g. office or hospital).  We know this as "episodic care."  U.S. healthcare costs per capita have exceeded the costs in other developed countries without a proportionate improvement in outcomes.

As Berwick noted, the Commonwealth Fund Commission (2) ranked the U.S. healthcare system  66 on a scale of 100. This occurred at expenditures twice the level of the next most-costly nation. U.S. healthcare rankings versus other nations, included:

  • 31st on life expectancy,
  • 36th on infant mortality,
  • 28th on healthy male life expectancy, and
  • 29th on healthy female life expectancy.(2)

In simple terms, we are not paying more to get better health outcomes. Moreover, costs have grown faster in healthcare than in other sectors of our economy.

As we have focused on individual diseases and conditions, we have paid less attention to the lifestyle, economic and environmental factors, as well as public health services that contribute to our health outcomes:

  • Nutrition, including obesity,
  • Tobacco smoking,
  • Unsafe choices,
  • Domestic violence
  • Sedentary lifestyle (inactivity), and
  • Poor access to healthcare, including preventive services.

Likewise, the U.S. has seen an increase in chronic disease, especially in our elderly. Two-thirds of Medicare patients have two of more chronic diseases (3).

Population Health directs our attention and our efforts from an individual focus to the health of an entire population.  Of course, you must define the population for each discussion.  It could be the citizens of a community, the panel of a physician practice, a group of patients with a defined disease,  the participants of a health plan, or the population of an entire state.  So it is always important for one to define the population for study and intervention. The theory is that we can reduce costs and improve outcomes by shifting our attention to an entire population around a continuum of care.

Defining the Triple Aim

Berwick explains that the Triple Aim requires the "enrollment of an identified population, a commitment to universality for its members, and the existence of an organization (an 'integrator') that accepts responsibility for all three aims for that population" (1).  The Triple Aim consists of three interdependent, not independent goals. He recognizes that changes to one will affect the other two.  Thus an organization must strive to strike a balance among the three, and not sacrifice the outcomes of one subpopulation for another.

He made it clear that the traditional FFS model was not aligned to the Triple Aim. He also noted that electronic health records and access to data would be critical for success.

Drivers of Population Health

Since 2009, several legislative events moved U.S. healthcare in the direction of the Triple Aim and thus Population Health:

  • The American Recovery and Reinvestment Act of 2009 (ARRA, or "the stimulus"), which established the HITECH Act leading to the Meaningful Use EHR adoption measures for Medicaid and Medicare hospitals/providers.
  • The Patient Protection, Affordable Care Act (2010. PPACA, ACA, or ObamaCare), which provided more structure and funding for Accountable Care Organizations (ACOs), shared services models, and expanded access to health insurance.
  • Medicare Access and CHIP Reauthorization Act of 2015 (MACRA, enacted as the Medicare Quality Payment Program), which expanded physicians/providers benefits for better managing populations of patients.

Challenges of Population Health

As U.S. healthcare embraces Pop Health there are several challenges each organization must address:

  • Defining a population and the goals - As Berwick noted (1) "pursuing any one goal can affect the other two, sometimes negatively and sometime positively."  For example, reducing hospital readmissions through a longitudinal approach to congestive heart failure may reduce a hospital's operational income if not offset by reimbursement for value-based care over volume.
  • Digitalizing patient data - Though most hospitals and many physician offices have deployed electronic medical records, they may not represent a complete version of electronic health records due to incomplete adoption.
  • Interoperability - The ability of information systems to leverage their data across platforms.
  • Quality of clinical data - Clinical data may be unstructured and contain inaccuracies.
  • Quality of analytics - Many organizations are still in the early maturity stage of their analytics platforms.
  • Transition from fee-for-service (volume-based) to value-based care - Many organizations must balance current payor mixes to remain in business during the transition.
  • Burden of reporting - Many of the factors above make it difficult to determine/measure outcomes and report to third parties.

These and many others contribute to current challenges in Pop Health.  Follow the link below for further Population Health definitions.

 Learn the Processes, Tools and Technology of Pop Health


1. Berwick DM, Nolan TW, Whittington J. The Triple Aim: Care, health, and cost. Health Affairs. 2008 May/June;27(3):759-769. [Abstract at PubMed.gov].  [Link to full text article at Health Affairs].

Dr. Berwick at the time was president and CEO of the Institute for Healthcare Improvement (IHI) in Cambridge, Massachusetts.  Thomas Nolan and John Whittington were IHI senior fellows at the time of publication.

2. Cantor JC, et al. Aiming higher: Results from a state scorecard on health system performance, New York: Commonwealth Fund, June 2007; and Why not the best? Results from a national scorecard on U.S. health system performance, New York: Commonwealth Fund, September 2006.

3. The Centers for Medicare and Medicaid (CMS) at cms.gov.