Medicare beneficiaries more likely to receive appropriate ambulatory services in HMOs than in traditional medicare.

With quality-of-care bonus payments now available for Medicare Advantage health maintenance organizations (HMOs) and for accountable care organizations in traditional Medicare, the need to understand the relative quality of care delivered to Medicare enrollees has increased. We compared the quality of ambulatory care from 2003 through 2009 between beneficiaries enrolled in Medicare Advantage HMOs and those enrolled in traditional Medicare, and we assessed how the performance of various types of Medicare HMOs differed from that of traditional Medicare for these same measures. We found that beneficiaries in Medicare HMOs were consistently more likely than those in traditional Medicare to receive appropriate breast cancer screening, diabetes care, and cholesterol testing for cardiovascular disease. We also found that Medicare HMO physicians were rated less favorably by their patients than were physicians in traditional Medicare in 2003; however, by 2009 the opposite was true. Not-for-profit, larger, and older Medicare HMOs performed consistently more favorably on clinical measures and ratings of care than for-profit, smaller, and newer HMOs. Our results suggest that the positive effects of more-integrated delivery systems on the quality of ambulatory care in Medicare HMOs may outweigh the potential incentives to restrict care under capitated payments.