1. Department of Gastroenterology, Santo António Hospital, Porto University Hospital Center, Porto, Portugal;
2. Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal;
3. Department of Gastroenterology, Portuguese Oncology Institute of Porto, Porto, Portugal;
4. Department of Community Medicine, Health Information and Decision (MEDCIDS) and CINTESIS, Faculty of Medicine, University of Porto, Porto, Portugal
5. Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
6. Department of Endocrinology, Diabetes and Metabolism, São João University Hospital Center, Porto, Portugal
7. Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands