1. Department of Internal Medicine, Seoul National University College of Medicine, Bundang Hospital, Seongnam, Korea.
2. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Hanyang University College of Medicine, Guri Hospital, Guri, Korea.
4. Department of Internal Medicine, Daegu Catholic University College of Medicine, Daegu, Korea.
5. Department of Internal Medicine, Chonbuk National University College of Medicine, Jeonju, Korea.
6. Department of Internal Medicine, Soonchunhyang University College of Medicine, Seoul, Korea.
7. Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea.
8. Department of Internal Medicine, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea.