1. Faculty of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
2. Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
3. Division of General Medicine, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
4. Division of Gastroenterology, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan