[1] Nottingham Univ Hosp NHS Trust, Nottingham, England
[2] Intercollegiate Comm Basic Surg Examinat, Nottingham, England
[3] Aberdeen Royal Infirm, Dept Colorectal Surg, Aberdeen, Scotland
[4] Nanyang Technol Univ, Lee Kong Chian Sch Med, Singapore, Singapore
[5] Univ Aberdeen, Dept Med Stat, Aberdeen, Scotland