1. Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
2. Department of Internal Medicine, College of Medicine, Konyang University, Daejeon, Korea
3. Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea
4. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea
5. Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Korea
6. Department of Internal Medicine, University of Ulsan College of Medicine, Ulsan, Korea