1. Department of Urology, Viborg Hospital, Viborg, Denmark
2. Vanderbilt University Medical Center, Nashville, Tennessee
3. Department of Clinical Epidemiology, Aarhus University Hospital, Skejby, Denmark
4. International Epidemiology Institute, Rockville, Maryland
5. Department of Urology, Aarhus University Hospital, Skejby, Denmark
6. Department of Epidemiology, School of Public Health, Boston University, Boston, Massachusetts