1. Department of Internal Medicine, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
2. Department of Internal Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
3. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Korea
4. Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea
5. Division of Gastroenterology, Department of Internal Medicine, Catholic Kwandong University International St. Mary's Hospital, Incheon, Korea
6. Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea