A national telephone survey finds that 60.6 percent of physician organizations report no current involvement and no plans to become involved in an accountable care organization (ACO) in the near future.

The study appears in the journal Health Services Research and is important because of how heavily ACOs have been promoted as a way to reign in healthcare costs while also improving quality of care. It the model can indeed deliver on that promise, the lack of physician group participation could be problematic for advocates of healthcare reform.

The researchers used data from the third National Survey of Physician Organizations that was conducted between January 2012 and May 2013. In a 40-minute survey, practices were asked questions about ACO participation, their business characteristics and which patient-centered medical home processes they were using in caring for patients.

The survey results revealed that only 23.7 percent of the 1,183 physician practices in the sample reported having joined an ACO. The researchers also found that these practices were different in some ways from the practices that had not joined and were not planning to join an ACO. In general, the ACO participating practices were larger practices or practices that had joined an independent practice association (IPA) or a physician-hospital organization (PHO). The practices that had joined ACOs also were less likely to be hospital owned and more likely to use patient-centered medical home processes to manage patient care. In addition, there was a regional variation with New England practices being more likely to have joined an ACO. Led by Massachusetts, healthcare reform has been a top political issue in the New England states, and that may account for the greater participation in ACOs in this region.

Since around one in six practices (15.7 percent) reported planning to join an ACO in the next year when the survey was done, it is possible that if the survey is redone in the future, it may reflect a higher number of ACO participating practices.