1. Department of Internal Medicine and Preventive Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Kyung Hee University College of Medicine, Seoul, Korea.
5. Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
6. Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.
7. Department of Internal Medicine, Ajou University College of Medicine, Suwon, Korea.
8. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
9. Department of Internal Medicine, Chungnam National University College of Medicine, Daejeon, Korea.
10. Department of Internal Medicine, Catholic University of Daegu School of Medicine, Daegu, Korea.