Enrollment in Medicare Advantage, the managed care program for Medicare beneficiaries, has grown rapidly, from 4.6 million enrollees in 2003 to 12.8 million by 2012, or 27 percent of all current Medicare beneficiaries. We analyzed utilization patterns of enrollees in Medicare Advantage health maintenance organization (HMO) plans compared to matched samples of people in traditional Medicare during 2003-09, to ascertain whether the HMO enrollees demonstrated different levels of use of services, which can be a hallmark of more integrated care. We found that utilization rates in some major categories, including emergency departments and ambulatory surgery or procedures, generally were 20-30 percent lower in Medicare Advantage HMOs in all years. Medicare Advantage HMO enrollees initially had lower rates of ambulatory visits and hospitalizations, although these rates converged by 2008; they also received about 10 percent fewer hip or knee replacements. In contrast, HMO enrollees underwent more coronary bypass surgery than patients in traditional Medicare. These findings suggest that overall, Medicare Advantage HMO enrollees might use fewer services and be experiencing more appropriate use of services than enrollees in traditional Medicare.
Landon, Bruce E., Alan M. Zaslavsky, Robert C. Saunders, L. Gregory Pawlson, Joseph P. Newhouse, and John Z. Ayanian. "Analysis Of Medicare Advantage HMOs Compared With Traditional Medicare Shows Lower Use Of Many Services During 2003–09." Health Affairs 31.12 (December 2012): 2609-2617.