But what does "improving population health" really mean? This is the question asked in a new viewpoint article by Weill Cornell Medical College researchers published in the March 20 issue of the
). The authors argue a clear definition is crucial in order to formulate effective health care and social service policy.
Section 3022 of the ACA, which created the Medicare Shared Savings ACO program, states the program "promotes accountability for a patient population."
"This phrase sets the tone for the meaning of population health as applied to ACOs -- implying that it is the health of the Medicare beneficiaries attributed to a provider organization, not the health of all people living in an ACO's geographic area," says lead author Dr. Douglas Noble, Commonwealth Fund Harkness Fellow in Health Care Policy and Practice in the Department of Public Health at Weill Cornell. Dr. Noble also serves as a public health physician and clinical lecturer in the global health, policy and innovation unit at Barts and the London School of Medicine and Dentistry in the United Kingdom.
"Many ACOs appear to interpret their responsibility for population health in medical terms -- that is, as a responsibility to provide preventive care for all their patients and care management for their patients with serious chronic diseases," says senior author Dr. Lawrence P. Casalino, the Livingston Farrand Associate Professor of Public Health and chief of the Division of Outcomes and Effectiveness Research at Weill Cornell. "This is a major step forward from the traditional model in medical care, which has been to focus on whatever patients appear in the physician's office, while the patient is in the office. However, it falls far short of working to improve the health of the population in a geographic area."
Despite the widespread use of the phrase "population health" tied to ACOs, it's not clear that ACOs actually have the incentives or the tools to improve the health of the entire community in which they are located, according to researchers.
"Population health depends not only on medical care, but also on social services, the public health system and, crucially, on socioeconomic factors, such as housing, education, poverty and nutrition," emphasize the Weill Cornell authors in their JAMA
article. "Talking about ACOs as if they are focusing on improving population health -- as opposed to improving medical care for their populations of patients -- leads to a lack of clarity about what ACOs are doing about population health and may divert attention away from social and public health services and from socioeconomic factors critical to health."
The authors do not suggest that ACOs should be responsible for population health defined as the health of everyone in their geographic area, because few if any ACOs have the expertise, authority, and incentives to act effectively in the areas of public health, social services and socioeconomic determinants of health. Instead, they suggest that the phrase "population health" should be clearly defined, and not used loosely in relation to ACOs.
"When population health is clearly defined, it becomes possible to think more specifically about what needs to be done to improve it, whether and how ACOs can help, the types of organizations with which ACOs will need to cooperate and the incentives that ACOs -- and other organizations -- will need to improve the health of the population in their geographic area," says Dr. Casalino.
The authors note that it has been suggested by other experts that ACOs could possibly contribute to improving the health of the whole population by functioning as part of "Accountable Health Communities," in which ACOs would cooperate with other organizations to improve geographical population health. Whether or not this is possible, or how this would be done is a difficult and complicated issue.
"It will only be possible to have this debate if the phrase 'population health' is used clearly, and not as a vague way of referring to what ACOs are currently doing," says Dr. Noble. "Otherwise, it will be very difficult to understand what ACOs are doing, what they are not doing and what they should be doing, who can do these things, how they can be measured and how and for whom incentives should be created."