1. Department of Internal Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
2. Department of Internal Medicine, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Korea.
3. Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
4. Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
5. Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea.