1. Department of Internal Medicine, Chonnam National University Hospital School of Medicine, Gwangju, Korea.
2. Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Inje University Sanggye Paik Hospital, Seoul, Korea.
4. Department of Internal Medicine, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Daegu Catholic University School of Medicine, Daegu, Korea.
6. Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea.
7. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.