1. Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, UK
2. National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham, UK
3. Ellen and Pinchas Mamber Institute of Gastroenterology and Liver Diseases, IBD Unit, Emek Medical Center, Afula, Israel
4. Department of Medicine, Mount Sinai Inflammatory Bowel Disease Centre, University of Toronto, Toronto, Canada