1. Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Korea
2. Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
3. Catholic Kwandong University International St. Mary's Hospital, Incheon, Korea
4. Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea
5. Department of Internal Medicine, School of Medicine, Wonkwang University, Iksan, Korea
6. Department of Psychiatry, School of Medicine, Wonkwang University, Iksan, Korea
7. Department of Internal Medicine, Daegu Catholic University School of Medicine, Daegu, Korea
8. Digestive Disease Research Institute, Wonkwang University College of Medicine, Iksan, Korea