1. School of Medicine; International Medical University; Kuala Lumpur Malaysia
2. Gastroenterology and Hepatology Unit, Internal Medicine Department; Faculty of Medicine, Ain Shams University; Cairo Egypt
3. Department of Therapy; I.M. Sechenov First Moscow State Medical University; Moscow Russian Federation
4. Department of Gastroenterology; Botkinskaya Hospital; Moscow Russian Federation
5. Cochrane Hepato-Biliary Group; Copenhagen Trial Unit, Centre for Clinical Intervention Research, The Capital Region, Copenhagen University Hospital - Rigshospitalet; Copenhagen Denmark