1. Department of Urology, Paediatric Urology and Urological Oncology; Kliniken Essen-Mitte; Essen Germany
2. Institute for Medical Informatics, Biometry and Epidemiology; University of Duisburg-Essen; Essen Germany
3. Department of Anaesthesiology; Critical Care Medicine and Pain Therapy; Kliniken Essen-Mitte; Essen Germany
4. Die GesundheitsUnion; Urology Health Center; Wuppertal Germany