1. Department of Medical Education, Yokohama City University School of Medicine, Kanagawa, Japan.
2. Medley, Inc., Tokyo, Japan.
3. Holon Toriizaka Clinic, Tokyo, Japan.
4. The Medical Corporations of Sawakou-kai Tezuka Otorhinolaryngology, Kanagawa, Japan.
5. The Medical Corporations of Seizin-kai Kikuchi Otorhinolaryngology, Miyazaki, Japan.
6. The Medical Corporations Fujimura Otorhinolaryngology Clinic, Hyogo, Japan.
7. The Medical Corporations of Nishikawa Nishikawa Otorhinolaryngology, Osaka, Japan.
8. Yamamoto Otorhinolaryngology, Tokyo, Japan.
9. Kamata Ida Otorhinolaryngology, Tokyo, Japan.
10. Department of Biostatistics, Yokohama City University School of Medicine, Kanagawa, Japan.
11. Department of Otorhinolaryngology, Head & Neck Surgery, Yokohama City University School of Medicine, Kanagawa, Japan.