Prevalence of dementia in the rural village of Hanazono-mura, Japan.

We studied the prevalence of dementing disorders in a rural municipality of Japan (Hanazono-mura), using a door-to-door two-phase design. In phase 1, the Hasegawa's Dementia Scale-Revised was applied as a screening test to all subjects aged 65 years and older (n = 201). Among subjects screened positive, 17 were diagnosed with dementia in phase 2. The prevalence (cases/100 aged 65 years and older) was 8.5 for all types of dementia, 3.5 for Alzheimer's disease, 3.0 for vascular dementia, and 2.0 for other dementia (including mixed dementia). The prevalence of dementia was slightly but consistently higher in men than women at all ages. The overall prevalence was higher in women for Alzheimer's disease and in men for vascular dementia.