1. Department of Internal Medicine, Eulji University School of Medicine, Daejeon, Korea.
2. Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
3. Department of Internal Medicine, Konyang University College of Medicine, Daejeon, Korea.
4. Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
5. Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
6. Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.