1. Institute of Applied Health Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
2. Urology Department, Nottingham University Hospitals NHS Trust, Nottingham NG5 1PB, UK
3. Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
4. Department of Colorectal Surgery, Aberdeen Royal Infirmary, Aberdeen AB25 2ZN, UK
5. Department of Medical Statistics, Institute of Applied Health Sciences, University of Aberdeen, AB25 2ZD, UK
6. Department of Maxillo-Facial Surgery, Queen Alexandra Hospital, Portsmouth, PO6 3LY, UK