1. Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
2. Department of Internal Medicine, Chonbuk National University Hospital, Chonbuk National University Medical School, Jeonju, Korea
3. Department of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon, Korea
4. Department of Internal Medicine, Inje University Busan Paik Hospital, Busan, Korea