The marriage of public health and preventive medicine: Population health

Population health was defined more than a decade ago, in 2003, as the study of health status of a group of individuals. Although this may seem obvious, it’s a new direction for health care providers who have traditionally been trained to care for one patient at a time.

However, although population heath may be a new term, it is not a new concept. When John Snow noticed a certain population—those living in the area of London around the Broad Street pump—were dying of cholera in 1854, he performed classic epidemiological work to determine that it was the water from the well that was making people sick.

“Population health science is really trying to understand the determinants, the epidemiology and the outcomes of diseases,” said Jay Maddock, PhD, dean of the Texas A&M School of Public Health. “Where it differs from classic public health work is that population health also includes preventive medicine interventions, dealing with people who might be at risk for certain conditions.”

It is the combination of traditional public health practices—like recommending the population as a whole stop smoking—with preventive medicine interventions—like a provider recommending that an individual patient stop smoking—that makes up population health. “For maximum health benefits, both approaches are vitally important going forward,” Maddock said.

Populations are perhaps most commonly thought of in terms of geography, as in the Broad Street pump example, or as in Texas A&M’s efforts to improve the health of people in South Texas. There might be specific problems associated with certain areas, like a lack of access to nutritious options for people living in food deserts.

However, populations can also be broken down in other ways, such as by racial or ethnic groups—who might tend to have differing rates of diseases—or by age. “The Medicare-eligible population has a specific set of diseases, and their health issues are different of those of younger people,” Maddock said. “We know from epidemiological studies that falls are a very serious problem for this group, for example.” Therefore, trying to improve the health of the older population might involve interventions like fall prevention or Texercise, an exercise and nutrition program for older adults.

More than just these public health interventions though, population health is closely linked to precision medicine. “People who have a family history of a certain disease can be a population,” Maddock said. Keeping that population healthy might involve increased screenings and other aspects of preventive care.

Still, population health is a relatively new discipline and Maddock says there is still opportunity for it to grow. “I think we haven’t gotten to where population health needs to be,” he said. “At some point, we will be able to use big data and real-time tracking and analytics to determine if things are working in a population.” With more information, researchers could have a better idea of what is driving a higher rate of disease in a population: environmental, behavioral or genetic factors, or something else entirely. Because there are so many variables, only by all of the health disciplines working together will the promise of population health be realized.

“Population health cuts across all of the health sciences: There are people predisposed to develop certain dental conditions, and pharmacy is involved because drugs work differently in different populations based on age, weight or organ functioning,” Maddock said. “Although it’s a discipline that might be most associated with public health and medicine, population health studies really involve us all.”