1. Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, Umeå, Sweden
2. Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
3. Department of Clinical and Experimental Medicine, Division of Urology, Linköping University, Linköping, Sweden
4. Department of statistics, Umeå School of Business, Economics and Statistics (USBE), Umeå University, Umeå, Sweden
5. Department of Surgery, Nyköping County Hospital, Nyköping, Sweden