The study also identified common characteristics of physician-led ACOs:
David Muhlestein, director of research for Leavitt Partners and co-author of a recent white paper, A Taxonomy of Accountable Care Organizations: Different Approaches to Achieve the Triple Aim, says the physician-led ACO model doesn't mean that hospitals can't also be successful. He points to the hospital-led ACOs that are part of the CMS Pioneer ACO program.
"From the Pioneer [ACOs}, where they saved money was by moving patients to a lower-acuity setting," says Muhlestein. "They have a strong primary care component … and can drive change from the outpatient side."
But hospital-led ACOs face a more difficult task because they can't sacrifice inpatient revenue, so the component of care hospitals have to change is on the outpatient side, Muhlestein points out.
In contrast, physicians already are front-and-center with outpatients, which may be one reason physician-led ACOs are growing in number and may be better at capturing savings, says Ellis "Mac" Knight, MD, senior vice president and chief medical officer for Coker Group, a healthcare consulting firm.