1. Department of Otorhinolaryngology-Head and Neck Surgery, Daejin Medical Center, Bundang Jesaeng General Hospital, Seongnam, Gyeonggido, Republic of Korea
2. Department of Statistics and Actuarial science, Soongsil University, Seoul, Republic of Korea
3. Department of Biostatistics, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
4. Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea, City, Country