1 Centre for Medical Informatics, Usher Institute, University of Edinburgh, Edinburgh, EH16 4UX, UK.
2 Department of Clinical Surgery, University of Edinburgh, Edinburgh, EH16 4UX, UK; Department of Surgery, Stanford University, Stanford, CA, USA.
3 Department of Clinical Surgery, University of Edinburgh, Edinburgh, EH16 4UX, UK; Department of Surgery, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
4 Centre for Medical Informatics, Usher Institute, University of Edinburgh, Edinburgh, EH16 4UX, UK. Electronic address: [email protected].