Reflections on the Connection Between Health Care Quality and Population Health

The concept of quality in health care can be traced back >100 years to Ernest Amory Codman, MD, a surgeon affiliated with a prestigious Boston hospital in the early 1900s. ¹ Codman strongly believed in following up on all of his patients. He meticulously recorded outcomes and noted instances in which care could be improved in the future. For this, he was removed from the hospital's medical staff. Undeterred, he opened a new hospital where evaluation of care was required. He went on to set up the first national registry for bone sarcoma, and cofounded the American College of Surgeons.

Over subsequent years, multiple quality concepts were introduced by various entities, and these are now firmly embedded in all facets of health care. In 2001, the National Academies of Science, Engineering and Medicine (NASEM) clarified 6 distinct domains of health care quality: Safe, Timely, Efficient, Effective, Equitable, and Patient-Centered. ²

But what about health care quality at the population level? A relatively new field of study, population health was originally defined by David Kindig and Greg Stoddart in 2003 as “the health outcomes of a group of individuals, including the distribution of such outcomes within the group.” ³ In lieu of a quality framework, the population health construct was derived from the “determinants of health”: medical care, public health interventions, aspects of the social and physical environments, genetics, and individual behavior. ³ It follows that much of the early growth in population health stemmed from public health concepts.

Twenty years later, the fields of population health and health care quality have started to meld. The impetus for this was a 2013 NASEM publication that articulated concepts whereby population health quality measures might be defined in the context of naturally occurring overlaps with the stated aims of population health—risk-reducing (safety), transparent (timely), efficient, effective, equitable, and population-centered (patient-centered)—along with 3 additional aims (proactive, health promoting, and vigilant.) ⁴

One reason for the overlap between health care quality and population health is the growing recognition that policies do not bring about change; rather policy is the basis for generating changes to improve outcomes—and this can be difficult. Philadelphia's tax on soda is a good example. Framed as a health improvement policy, the tax on purchases of sugar-based beverages was intended to combat the growing prevalence of obesity and diabetes in the city's population. ⁵ The tax was implemented in 2017 after multiple failed efforts to pass it and legal challenges along the way.

Hailed as an opportunity to improve population health by focusing on determinants of health, the revenue produced by the tax was to be invested in education and the built environment.

Opponents viewed it as a regressive tax that disproportionately impacted lower socioeconomic populations. Although one may find it hard to argue that decreasing the consumption of sugar-based beverages is bad, the tax never found support, the revenue never met stated objectives, and obesity and diabetes in Philadelphia continue to increase.

A resolution to repeal the soda tax was introduced in the City Council in January 2022. It would have included initiatives that focus on diabetes prevention and that intervene when individuals are identified with prediabetes. This approach has been shown to lower the likelihood of progression to diabetes in multiple cities. ⁵ Importantly, the optics are much better for a government that purports to help residents solve a problem than for a government that imposes a tax to force behavior change.

A second reason for the overlap between health care quality and population health is our deepening understanding of the social determinants of health (SDOH) and their considerable influence on quality indicators. For example, “readmission to the hospital within 30 days of discharge” has been used as a hospital quality indicator at the national level since 2012. ⁶ However, we have become increasingly aware that a hospital's performance on this measure may be greatly influenced by patients' ability to schedule an appointment (access to care and transportation), medication use (ability to pay, family support, and transportation), and unexpected complications (eg, falls due to defects in the built environment, lack of follow-up due to insufficient insurance coverage). In fact, SDOH impact 50% or more of health outcomes; clinical care accounts for 20% or less. ⁷

A third reason is our acknowledgement of wide-ranging adverse health outcomes that are attributable to structural and institutional racism. Whether through delays in diagnosis or differential treatment, the Black, Indigenous, and People of Color (BIPOC) community has suffered from health inequities for as long as there has been structured health care. ⁸ Onset of chronic disease (eg, diabetes, kidney disease) is one paradigm where this plays out. Food deserts, lack of access to care, socioeconomic inequities, body shaming, differing measurement systems that reflect racial stereotypes, and lack of genomic understanding that race is a social construct—all of these contribute to the incidence and prevalence of disease.

Solving population health problems requires equipping more health care providers with the tools and skills necessary to become allies in the quest for health equity, safe health care, and improved access to care. Although training of population health experts is in its nascency, health care quality is typically an integral part of these training programs. Similar to almost everything in health care, it is a continuum.