1. Department of Urology, Mayo Clinic, Rochester, Minnesota
2. Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, Minnesota
3. Division of Epidemiology, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, Minnesota
4. Merck Research Laboratories, West Point, Pennsylvania
5. Southern California Permanente Medical Group, Pasadena, California