1. Department of Medicine, Faculty of Medicine, Kuwait University, Jabriyah, Kuwait
2. Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
3. Division of Gastroenterology, The McGill University Health Center, Montreal General Hospital, McGill University, Montreal, Canada
4. Research Institute of the McGill University Health Center, Montreal, Canada
5. Division of Clinical Epidemiology, The McGill University Health Center, Montreal General Hospital, McGill University, Montreal, Canada