1. Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea.
2. Department of Otorhinolaryngology-Head and Neck Surgery, Hallym University College of Medicine, Chuncheon, Korea.
3. Department of Internal Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
4. Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea.
5. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.