Prevalence Rate and Risk Factors of Dementia Compared between Urban and Rural Communities of the Metropolitan Kwangju Area

Shin, Il Seon; Kim, Jae Min; Yoon, Jin Sang; Kim, Suk Jae; Yang, Su Jin; Kim, Woong Jang; Lee, Seung Hyun; kang, Soon Ah; Kwak, Ji Young; Lee, Hyung Yung

Abstract

OBJECTIVES
The purpose of this study was to investigate the prevalence rate and risk factors of dementia in an urban and a rural sample of older persons in the metropolitan Kwangju area, Republic of Korea. In addition, the prevalence rate and risk factors of dementia between the two samples were compared.
METHODS
A two-phase epidemiological study of residents aged 65 or over(N=1,598) was conducted in a highly developed, urban and a non-contiguous, poorly developed, rural area of metropolitan Kwangju. In the first(screening) phase, 38 trained research assistants collectively performed in-home interviews for all participants. Detailed sociodemographic characteristics were gathered and the Korean version of Mini-Mental State Examination(MMSE-K) was administered. In the second(diagnosing) phase, diagnosis of dementia was established for those scoring 24 or less on the MMSE-K in the screening phase(N=431), and etiological types of dementia were classified to Alzheimer's disease (AD), vascular dementia(VaD) or miscellanous type by two teams of experts. Prevalence rate of dementia was determined in the participants, and age-standardized prevalence rate adjusted by age distribution in metropolitan Kwangju was estimated. For AD, the risk factors were investigated in all participants, and analyses were repeated for the urban and rural samples separately.
RESULTS
The participating rates in the first and second phases were 71.0%(N=1,134) and 83.2% (N=410), respectively. In the participants, the prevalence rates of dementia(all types), AD and VaD were 9.7%, 5.2% and 1.8%, respectively. The age-standardized prevalence rates were 10.7%, 5.7% and 1.9%, respectively. Aging, female gender and no education(complete lack of formal education) were identified as independent risk factors for AD. No difference between the urban and rural samples was observed in the prevalence rates of dementia(all types), AD and VaD. However, risk factors for AD differed between these areas. In the urban sample, no education was the only significant factor; whereas, aging and female gender were identified as risk factors in the rural sample.
CONCLUSION
A high prevalence rate of dementia was observed among old persons in metropolitan Kwangju, consistent with previous studies conducted in other Korean areas. The risk factor profiles for AD differed between urban and rural settings. The results of this study reflect the current status of dementia in Korea and suggests that appropriate management and prevention strategies for dementia should be tailored toward the geographic settings.