Changes in the characteristics of definite Meniere's disease over time in Japan: A long-term survey by the Peripheral Vestibular Disorder Research Committee of Japan, formerly the Meniere's Disease Research Committee of Japan

Conclusion. The incidence of new cases of Meniere's disease (MD) in elderly patients aged 60 years or more was found to have increased over time after correction for age distribution in the overall population. Job- and care-related fatigue may be involved in the recent increase in elderly-onset cases because physical and mental fatigue can induce onset of the disease. Objectives. Changes over time in the epidemiologic characteristics of MD in Japan were analyzed. Materials and methods. Between 1975 and 2006, four nationwide, multi-center surveys of MD were conducted by the Meniere's Disease Research Committee of Japan (1975-1976) and the Peripheral Vestibular Disorders Research Committee of Japan (1982-1984, 1990, and 2001-2006). Information was collected by the committee members on a total of 1368 de novo cases of definite MD, 520 reported in the first survey, 290 in the second survey, 148 in the third survey, and 410 in the fourth survey. Results. Clear changes were seen over time in the population-adjusted sex distribution of the disease and population-adjusted age at onset. The number of definite MD cases in females increased over time relative to the number of cases in males. The proportion of cases in which onset occurred at 60 years of age or more increased over time when the number of cases in each age group was adjusted for changes in age distribution of the population over time. From the time of the third survey, there was a slight increase in the proportion of cases with bilateral involvement.