1. Department of Internal Medicine, Hanyang University Guri Hospital, College of MedicineHanyang University Guri Korea
2. Division of Gastroenterology, Department of Internal Medicine, Hallym University Dongtan Sacred Heart Hospital, College of MedicineHallym University Hwaseong Korea
3. Department of Global Health DevelopmentHanyang University Seoul Korea
4. Division of Gastroenterology, Department of Internal MedicineYonsei University College of Medicine Seoul Korea