Prevalence of dementia and its subtypes in an elderly urban Korean population: Results from the Korean longitudinal study on health and aging (KLoSHA)

Background/Aims: We estimated the prevalence of dementia and its major subtypes in an elderly urban Korean population. Methods: A study population of 1,118 Korean elders was randomly sampled from the residents aged 65 years or older living in Seongnam, Korea. Standardized face-to-face interviews, and neurological and physical examinations were conducted on 714 respondents. Dementia was diagnosed according to the DSM-IV diagnostic criteria, and its subtypes were determined according to the criteria of the NINCDS-ADRDA, the NINDS-AIREN, and the consensus guideline proposed by McKeith et al. [Neurology 1996;47:1113-1124]. Results: The estimated age- and gender-standardized prevalences were 6.3% for dementia (95% CI = 4.5-8.1), 4.8% for Alzheimer's disease (AD; 95% CI = 3.3-6.4), 1.0% for vascular dementia (VD; 95% CI = 0.3-1.8), and 0.4% for dementia with Lewy bodies (DLB; 95% CI = 0.0-0.9). The prevalence of AD consistently increased with age, whereas that of VD peaked at age 75-79 years and decreased thereafter. Of the dementia patients, 72.0% were in the very mild or mild stages of the disease. Conclusions: The prevalence of dementia in a typical urban area of Korea was estimated to be 6.3%, and AD was the most prevalent subtype. DLB was less prevalent than VD among these community-dwelling Korean elders.