1. Department of Otolaryngology, Mita Hospital, International University of Health and Welfare, Tokyo
2. Department of Otolaryngology, Saiseikai Utsunomiya Hospital, Tochigi
3. Department of Otolaryngology, Head and Neck Surgery, Tokyo Medical University
4. Department of Otolaryngology, Head and Neck Surgery, School of Medicine, Keio University, Tokyo
5. Department of Otolaryngology, NHO Osaka National Hospital, Osaka
6. Department of Otolaryngology, Head and Neck Surgery, School of Medicine, Kyorin University, Tokyo
7. Department of Otorhinolaryngology, NHO Mie National Hospital, Mie
8. Department of Otolaryngology, Head and Neck Surgery, School of Medicine, The University of Tokyo, Tokyo
9. Department of Otolaryngology, Keiyu Hospital, Kanagawa
10. Department of Otolaryngology, NHO Tokyo Medical Center
11. Department of Medical Statistics, Graduate School of Medicine, Osaka Metropolitan University, Osaka
12. Department of Psychiatry, Institute of Medicine, University of Tsukuba, Ibaraki, Japan