LAUSR

Abstract Background Delayed endolymphatic hydrops (DEH) is a rare disease, and the actual number of patients in Japan remains unknown. Objective To investigate the number and prevalence of patients with DEH in Japan. Methods In total, 781 departments of otolaryngology in Japan were selected for survey by stratified random sampling according to the total number of hospital beds. We sent questionnaires to the target departments and collected data regarding the number of patients with DEH who visited those departments in 2019. Results The overall response rate was 68.0% (531 departments). The estimate number of patients with DEH in Japan was 962, and the prevalence was calculated to be 0.8 per 100,000 population. Conclusion Patients with DEH were extremely rare in Japan. Significance This may be the first nationwide epidemiological study on the number and prevalence of patients with DEH in Japan or in the world.