1. Department of Medicine and Therapeutics, Prince of Wales Hospital, Shatin, Hong Kong, China
2. Department of Internal Medicine, National Cheng Kung University Hospital, Tainan City, Taiwan
3. Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan
4. Division of Gastroenterology, Department of Internal Medicine, Yonsei University Severance Hospital, Seoul, Korea
5. Department of Internal Medicine, The Catholic University of Korea, Seoul, Korea