From NEJM: Can ACOs work?

http://www.ncbi.nlm.nih.gov/pubmed/22296073

N Engl J Med. 2012 Feb 2;366(5):393-5.
Keeping score under a global payment system.
Landon BE.
Source
Department of Health Care Policy, Harvard Medical School, and Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Boston, USA.



"Conceptually, global payment represents an important opportunity for changing the perverse incentives inherent in our current fee-for-service system. To be successful, however, ACOs must pass these incentives along to their member physicians, who continue to be responsible for most utilization decisions. Although organizations can implement various managerial strategies to influence physicians' decision making (e.g., radiology decision support and prior authorization), ACOs are unlikely to reduce the rate of increase in health care spending without some essential changes in the behavior of member physicians — and therein lies the rub. The fundamental questions become how ACOs will choose to divide their global budgets and how their physicians and other service providers will be reimbursed. Thus, this system for determining who has earned what portion of payments — keeping score — is likely to be crucially important to the success of these new models of care."