1. Laboratory of Hygiene, Social and Preventive Medicine and Medical Statistics, School of Medicine, Faculty of Health Sciences Aristotle University of Thessaloniki Thessaloniki Greece
2. Department of Gastroenterology and Hepatology General Hospital of Thessaloniki “G. Papanikolaou” Thessaloniki Greece
3. 3rd Department of Internal Medicine, G. N Papageorgiou Aristotle University of Thessaloniki Thessaloniki Greece
4. Division of Gastroenterology and Hepatology, 1st Department of Internal Medicine, AHEPA University Hospital, School of Medicine, Faculty of Health Sciences Aristotle University of Thessaloniki Thessaloniki Greece