Prevalence of Dementia in the Elderly of an Urban Community in Korea

Kim, Dong Hyun; Na, Duk L; Yeon, Byeon Gil; Kang, Yeonwook; Min, Kyung Bok; Lee, Soo Hyun; Lee, Sang Suk; Lee, Mi Ra; Pyo, Ok Jung; Park, Chan Byung; Kim, Sunmean; Bae, Sang Soo

Abstract

OBJECTIVES
In Korea, as in most countries, there will be a sharp increase in the number of dementia patients in the near future. However basic data on dementia prevalence, which is important in defining epidemiologic characteristics and in implementing preventive strategy, are limited. This study was conducted to estimate the prevalence rate of dementia in the urban elderly aged 65 or older in Kwangmyung, Korea.
METHODS
A two phase design was used for case finding and case identification. In phase I, a representative sample aged 65 or older was selected and interviewed by door-to-door survey with a Korean version of the Mini-Mental State Examination (K-MMSE). In phase II, Of the 946 subjects interviewed in phase I, 356 elderly were randomly selected disproportionately according to K-MMSE score. Of these elderly, 223 (61.5%) underwent standardized clinical evaluations, including psychiatric interview, neurological examination, and neuropsychological assessment. Dementia was diagnosed by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. The diagnosis of Alzheimer's disease (AD) was made by National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association(NINCDS-ADRDA) criteria and vascular dementia (VD) by DSM-IV.
RESULTS
The overall weighted prevalence rate of all dementia among Kwangmyung residents aged 65 or older was 12.8%(age-adjusted rate: 13.0%, 95% Confidence Interval[CI]: 10.6-15.3%). Women had much higher prevalence rate than men even when age was controlled(15.9%[95% CI 12.6-19.2%] vs 7.5%[95% CI 4.6-10.4%]). The rates of dementia were 5.2%, 12.2%, 17.0%, and 34.3% for the age groups of 65-69, 70-74, 75-79 and 80 and over, respectively. The rate of AD appeared to be slightly higher than that of VD(5.2% vs 4.8%), though not statistically significant. Most of the cases(69%) were mild dementia according to CDR(<1) in these subjects.
CONCLUSIONS
These results showed that the prevalence rate of dementia among urban elderly in Korea appears to be higher than those of other Asian countries.