1. Royal Free Campus, UCL Medical School; Department of Surgery; Royal Free Hospital, Rowland Hill Street London UK NW3 2PF
2. Royal Free Campus, UCL Medical School, London; 9th floor, Royal Free Hospital Pond Street London UK NW3 2QG
3. Copenhagen Trial Unit, Centre for Clinical Intervention Research, Department 7812, Rigshospitalet, Copenhagen University Hospital; The Cochrane Hepato-Biliary Group; Blegdamsvej 9 Copenhagen Denmark DK-2100