1. From the Departments of Urology and Biostatistics, University of California Los Angeles, Department of Surgery, Veterans Affairs Greater Los Angeles Health Care System, Los Angeles, the Section of Urology, Veterans Affairs Palo Alto Health Care System, Department of Urology, Stanford University School of Medicine, Palo Alto, the Departments of Urology, University of California, San Francisco, San Francisco, and Naval Medical Center, San Diego, California