1. Department of Urology, Johns Hopkins School of Medicine, Baltimore, Maryland
2. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
3. Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins Medical Institutions, Baltimore, Maryland
4. Department of Urology, Stanford University School of Medicine and Department of Surgery, Veterans Administration Medical Center, Palo Alto
5. Department of Surgery, Veterans Administration Greater Los Angeles Healthcare System and Department of Urology, University of California-Los Angeles School of Medicine, Los Angeles
6. Department of Urology, San Diego Naval Hospital, San Diego
7. Department of Surgery, Veterans Administration Medical Center San Francisco and Department of Urology, University of California, School of Medicine, San Francisco, California
8. Department of Surgery, Veterans Administration Medical Center and Section of Urology, Medical College of Georgia, Augusta, Georgia