1. Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, AB24 3FX, UK
2. Urology Department, Nottingham University Hospitals, Nottingham, NG5 1PB, UK
3. Department of Maxillo-Facial Surgery, Queen Alexandra Hospital, Portsmouth, PO6 3LY, UK
4. Medical Statistics Team, Institute of Applied Health Sciences, University of Aberdeen, AB24 3FX, UK
5. Department of Colorectal Surgery, Aberdeen Royal Infirmary, Aberdeen, AB25 2ZN, UK
6. Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore