1. From the Medical Practices Evaluation Center, Massachusetts General Hospital and Harvard Medical School, Center for Survey Research, University of Massachusetts and Department of Urology, Tufts University School of Medicine, Boston, Massachusetts
2. Departments of Urology, University of Wisconsin at Madison, Madison, Wisconsin
3. Johns Hopkins University, Baltimore, Maryland
4. University of Rochester Medical Center, Rochester, New York
5. Section of Urology, The University of Kansas Medical Center, Kansas City, Kansas