Heidelberg University - Salem Medical Center, Semmelweis University - Gastroenterology Division, Hospital of the Ministry of Interior and Administration - Department of Internal Medicine, Cardiology, Gastroenterology and Endocrinology, Fortis Hospitals - Institute of Gastro and Liver Diseases, Ahvaz Jundishapur University of Medical Sciences - Alimentary Tract Research Center, University Hospitals Leuven - Department of Gastroenterology and Hepatology, Colentina Clinical Hospital - Gastroenterology Division, University of Leipzig MedicalCenter - Medical Department II, Hospital da Senhora da Oliveira - Department of Gastroenterology, Ospedale dei Castelli, Universidad San Ignacio de Loyola - Unidad de Revisiones Sistemáticas y Meta-análisis (URSIGET), University Medicine Greifswald - Department of Medicine A, University Hospital Center Zagreb - Endoscopy Unit, National University of Malaysia (UKM) - Gastroenterology and Hepatology Unit, Seoul National University - Liver Research Institute, Hanoi Medical University - Internal Medicine Faculty, Hashemite University - Faculty of Medicine, Kaiser Permanente of Orange County - Department of Gastroenterology, Fudan University - Endoscopy Center and Endoscopy Research Institute and Al-Azhar University, Cairo - Department of Internal Medicine