Teams of health care providers called Accountable Care Organizations participating in the Medicare Shared Savings Program have saved Medicare between $4.1 billion and $8.1 billion from 2012 through 2019, according to a new study from Weill Cornell Medicine investigators. The study, published April 28 in JAMA, is thought to be the first to investigate the long-term impact of the program. Launched in 2012, the Medicare Shared Savings Program (MSSP) was established through the Affordable Care Act. Instead of making payments based on the volume of services—what's called fee-for-service reimbursement—MSSP incentivizes clinicians and health care organizations by setting certain quality targets and allowing providers to share in part of any savings that result from more efficiently managing patient care. In a comprehensive longitudinal study, Weill Cornell Medicine researchers compared medical spending for more than 8 million Medicare patients who were treated either by Accountable Care Organizations (ACOs) or other health care organizations. We found a significant reduction in spending per patient with providers working together as ACOs compared with organizations that were not in ACOs, and that reduction in spending increased over time." Dr. Dhruv Khullar, senior author, associate professor of population health sciences at Weill Cornell Medicine and a hospitalist at NewYork-Presbyterian/Weill Cornell Medical Center First author Dr. Amelia Bond, also an associate professor of population health sciences at Weill Cornell Medicine, co-led the research to analyze the long-term effects of the program. A long time coming Initial assessments of the shared savings program suggested that ACO providers generated only a small savings, if any, but those studies often looked at only the initial years of the program. "We felt it was important to update those estimates because policymakers need recent data to make decisions about the future of the program," said Dr. Khullar. The new study showed that MSSP generated a relatively large savings, and that the savings grew over time. Compared with costs for patients in non-ACOs, ACO per-patient costs were lower by an average of $142 in the first three years of the program. After six years in the program, ACOs saved even more—an average of $294 per patient—than non-ACOs. The researchers found that smaller ACOs and those led by physician groups were more effective at lowering costs than larger ACOs or those affiliated with hospitals. Regardless of the size or leadership, ACO spending reductions increased over time. Overall, the program saved the government billions of dollars during the study period. "There's an ongoing national debate that has been re-energized because many value-based payment programs are either being cut short or haven't shown that much improvement," said Dr. Bond. "This work is important because it shows, in this longer-term view, that ACOs in the Medicare Shared Savings Program have been saving money." Assessing quality The program has saved money, but have health care providers cut corners to achieve this goal? According to initial studies from other research groups, the quality of medical care from ACOs appears to be on par or possibly somewhat better than those that do not participate in the program. "Some of the qualitative work we've done suggests that ACOs may be doing things that support patients in ways that go beyond medical treatment," said Dr. Khullar. "Many ACO leaders report trying to meet patients social or behavioral health needs as well. But I think more work is needed to understand how effective those efforts have been." The research team plans to examine the effect of ACOs on care quality in their next study. They also hope to examine how quality of care varies for different patient subgroups within the overall population of patients that ACOs care for. This work was supported by Arnold Ventures and the Physicians Foundation Center for the Study of Physician Practice & Leadership at Weill Cornell Medicine.