The General Accounting Office (GAO) has issued a report recommending physician profiling, which they define as identifying efficient physicians. The entire report, i.e., GAO-07-307, is available at the following link: http://www.gao.gov/new.items/d07307.pdf
Following are key findings:
GAO estimates that physician account for 20% of the total health care expenditures, but influence 90% of total expenditures through referrals