1 Department of Medicine, Division of Gastroenterology and the Department of Clinical Epidemiology, Biostatistics and Occupational Health, McGill University Health Centre, Montreal, Quebec, Canada alan.barkun@muhc.mcgill.ca.
2 Yale School of Medicine, New Haven, Connecticut, USA.
3 Division of Gastroenterology, McMaster University, Hamilton, Ontario, Canada.
4 Division of Gastroenterology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.