Prevalence estimation of dementia in a rural area of Korea

OBJECTIVES: A cross-sectional survey was conducted to estimate prevalence of dementia and to determine factors related to dementia among residents in a rural area, Yonchon county, Korea, in 1993. PARTICIPANTS: Of the study population more than 65 years of age (n = 2171), 1674 persons participated in the cross-sectional survey using the Korean version of the Mini-Mental State Examination (MMSE-K). DESIGN: Subjects were defined as having dementia according to NINCDS-ADRDA criteria through direct interview by psychiatrists. A total of 436 subjects were selected randomly according to MMSE-K scores, and cases were confirmed as having either Alzheimer's or vascular dementia. RESULTS: The adjusted prevalence of dementia was estimated at 9.5%. The prevalence of total dementia was 8.8% for men and 9.9% for women. The prevalence of Alzheimer's disease was 3.2% for men and 5.3% for women and that of vascular dementia 3.1% and 2.1%, respectively. Age standardized prevalence of Alzheimer's disease was 4.5%, whereas that of vascular dementia was 2.5%. Using DSM-III-R criteria to stratify dementia patients according to severity showed the prevalence of mild, moderate, and severe Alzheimer's disease was 3.4%, 0.7%, and 0.5%, respectively. CONCLUSION: These results showed that the prevalence of dementia in Korea was similar to its presence in Western countries but different from that previously reported in other Asian countries, e.g., China and Japan.