As accountable care organizations (ACOs) continue to proliferate, these 250 or so newly created entities are charged with improving population health. One problem, according to a viewpoint published March 20 in the Journal of the American Medical Association, is the murky meaning of population health. This lack of clarity may interfere with ACOs’ capabilities to achieve essential outcomes.

“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,” wrote Douglas J. Noble, MD, MPH, and Lawrence P. Casalino, MD, PhD, both of Weill Cornell Medical College in New York City.

However, this approach is limited, as it overlooks other critical contributors to population health, including social services, the public health system and socioeconomic factors. This medicalization of the term population health may be short-sighted and problematic, according to the authors.

“Currently, ACOs lack the incentives and, in most cases, the capabilities to be responsible for population health defined as the health of everyone in their geographic area,” wrote Noble and Casalino. They called for a clear definition of population health. The downstream benefits of such clarity include a more specific definition of needs, improved understanding of whether and how ACOs can help, identification of essential partners and a foundation for informed decisions regarding incentives ACOs and organizations require to improve population health.

The authors referred to a report from University of California, Los Angeles, which differentiates the healthcare system 2.0 from 3.0. Version 2.0 focuses on chronic disease management, while 3.0 encompasses collaboration between medical organizations and public health to focus on primary prevention for an entire community.

ACOs are mired in a 2.0 mindset, according to the authors.

Critical questions about ACOs and possible incentives to improve population health can be answered only with a clear definition of population health. If population health is pigeonholed as improving medical care for ACO patients only, “it will be difficult to understand what ACOs are doing, what tasks they are not doing but should be done, who can do these tasks, how performance on these tasks should be measured, and how and for whom incentives should be created,” cautioned Noble and Casalino.