The prevalence of dementia in older people in an urban population of Korea: the Seoul study.

Abstract

To estimate prevalence of dementia and its subtypes in older people in Seoul, a metropolitan area of Korea, and compare these findings with estimates reported for other populations. The study employed a two-stage design for case identification. Initially, the Mini-Mental State Examination in the Korean version (MMSE-KC) of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) assessment packet was administered to all participants. Two hundred seventeen persons sampled from three levels of performance on MMSE-KC underwent the second-stage clinical evaluation based on the Korean Version of the CERAD assessment packet. The study was conducted in an urban community setting. Six hundred forty-three persons aged 65 and over participated in the study. Dementia was defined using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnostic features of dementia. Dementia prevalence ranged from 2.6% in persons aged 65 to 69 to 32.6% in persons aged 85 and older. Age-standardized prevalence was 8.2% for dementia, 5.4% for Alzheimer's disease, and 2.0% for vascular dementia. The prevalence estimates, which excluded very mild cases (clinical dementia rating index 0.5), were approximately 5.3% for dementia and 4.3% for Alzheimer's disease. The prevalence of dementia in older people in Seoul appears to be somewhat lower than in rural areas of Korea. Considering the difficulties involved in establishing a diagnostic threshold for dementia, actual differences in dementia prevalence between Asian populations are probably minimal.