ESTIMATED ANNUAL NUMBER OF PATIENTS TREATED FOR SENSORINEURAL HEARING-LOSS IN JAPAN

We mailed questionnaires to 98 university hospitals and 939 hospitals with 200 beds or more throughout Japan asking for information on patients treated for sensorineural hearing loss between January 1 and December 31, 1987. The number of patients treated for sensorineural hearing loss in 1987 in Japan was estimated as follows: i) sudden deafness in 13,900-19,600, ii) idiopathic bilateral progressive sensorineural hearing loss in 800-2,000, iii) perilymphatic fistula in 200-310, iv) mumps deafness in 200-400, and v) unilateral profound deafness in 2,000-3,000. Sex ratio (men over women) was 0.9 in sudden deafness and mumps deafness, 1.1 in idiopathic bilateral progressive sensorineural hearing loss and 1.5 in perilymphatic fistula. Patients were distributed with a definite peak from 50 to 59 years old in sudden deafness, from 30 to 39 years old in perilymphatic fistula, and two apparent peaks in teenagers and those aged 60-69 years in idiopathic bilateral progressive sensorineural hearing loss.