TUESDAY, Sept. 25, 2018 (HealthDay News) -- Physician-group accountable care organizations (ACOs) participating in the Medicare Shared Savings Program (MSSP) generated significantly more savings for Medicare that grew from 2012 to 2015 compared with hospital-integrated ACOs, according to research published in the Sept. 20 issue of the New England Journal of Medicine.
J. Michael McWilliams, M.D., Ph.D., from Harvard Medical School in Boston, and colleagues used fee-for-service Medicare claims from 2009 through 2015 to compare changes in Medicare spending for patients in ACOs before and after entry into the MSSP with concurrent changes in spending for local patients served by providers not participating in the MSSP.
The researchers found that MSSP participation was associated with differential spending reductions in physician-group ACOs, with larger reductions tied to longer participation in the program. Spending reductions by physician-group ACOs were significantly greater than the reductions in hospital-integrated ACOs. For physician-group ACOs that entered in 2012, the mean differential change in per-patient Medicare spending was −$474 by 2015 (−4.9 percent of the pre-entry mean; P < 0.001), −$342 for those that entered in 2013 (−3.5 percent; P < 0.001), and −$156 for those that entered in 2014 (−1.6 percent; P = 0.009). For hospital-integrated ACOs, the differential changes were −$169 (P = 0.005), −$18 (P = 0.78), and $88 (P = 0.14), respectively, which were significantly lower than for physician-group ACOs (P < 0.001). Physician-group ACOs' spending reductions totaled a net savings to Medicare of $256.4 million in 2015, while hospital-integrated ACOs' spending reductions were offset by bonus payments.
"After three years of the MSSP, participation in shared-savings contracts by physician groups was associated with savings for Medicare that grew over the study period, whereas hospital-integrated ACOs did not produce savings (on average) during the same period," the authors write.