http://www.nap.edu/books/030907343X/html/

This publication represents the quality of health care received by the people of the United States falls far short of what it should be. There is a gap between the health care services that should be provided based on current professional knowledge and technology and those that many patients actually receive. It is clear that all resources are not used effectively or safety. Study after study documents are overuse of many services-the provisions of services when the potential for harm overweighs possible benefits. At the same time studies also documents underuse of other services-the failure to provide services from which the patient would likely have benefited.