According to a new study published in the journal Radiology, participating in a Medicare Shared Savings Program (MSSP) Accountable Care Organization (ACO) makes mammography screening entities more likely to increase access to mammograms to more women, though other benefits were less clear and possibly nonexistent.

Understanding the influence of the MSSP ACOs is important to know whether the incentives of belonging to an ACO pushed by CMS are coming to fruition throughout different healthcare areas. As the study authors point out, screening mammography was the only imaging metric included in CMS’s evaluation, and so one of the only ways to understand the value of the MSSP in imaging. Do the financial incentives of ACOs increase the incidence of mammography screening?

The study looked at 333 MSSP member ACOs that had joined in 2013 and 2014, which included a total of more than five million people with Medicare. The use of screening mammography among ACOs varied from about 9 percent to about 90 percent, with the highest incidence of use in the Midwest (and the lowest in the South).

Of the 333 ACOs, 208 of them reported longitudinal results. Almost 62 percent reported an increased use of mammography screening within the ACO membership. Across the board, the incidence of mammography screening increased about 2.6 percent. The highest improvement in screening mammography since joining an ACO was more than 42 percent improvement.

However, increased incidence was the main improvement in screening mammography within the ACOs. There were no longitudinal improvements reported in total composite quality score. And changes in specific health outcomes connected to great screening was not available in this study’s data.

The researchers contribute the “small but significant improvements” seen in mammography screening incidence to the MSSPs. Based on financial incentives, the ACOs used strategies such as phone calls and letters to encourage unscreened patients to encourage to seek out mammography. They also offered free on-site screening, offered written material and used peer counseling to reach patients who could contribute to an increased use of screening mammography.

The study authors pointed out there was no control group in this study, yet they still believe it was membership in ACOs that increased this mammography screening incidence. Other cohorts showed decreased or stagnant growth among mammography screening during the same period, the researchers said. The evidence is especially strong when looking at the ACOs that had the highest increases in mammography screening.