PREVALENCE OF DEMENTIA IN AN URBAN AREA IN TAIWAN

This two-stage epidemiologic study was to investigate the prevalence a nd types of dementia among elderly people in the San-Min district of K aohsiung City in Taiwan. In stage one, the Chinese Mini-Mental Status Examination (CMMSE) and Blessed Dementia Rating Scale were employed. I n stage two, a comprehensive neurobehavioral examination and neuropsyc hologic tests were administered by neurologists and neuropsychologists . Dementia was defined by DSM-III-R criteria. The National Institute o f Neurological and Communication Disorders and Stroke-Alzheimer's Dise ase and Related Disorders Association guidelines for Alzheimer's disea se (AD) and the National Institute of Neurological Disorder and Stroke -Association international pour la Recherche et l'Enseignement en Neur osciences criteria for vascular dementia (VaD) were applied. A total o f 1,016 randomly selected elderly people participated in phase one; 13 1 people with CMMSE below cutoff values participated in phase two, Of whom 45 were confirmed to have a form of dementia. The prevalence of d ementia in this sample was 4.4% (3.2% in men and 5.8% in women); 2.0% for those 65 to 74 years old, 8.3% for those 75 to 84 and 24.4% for th ose greater than or equal to 85 years old; 6.0% for those who were ill iterate, 3.3% for those who attended grade-school; and 2.8% for those who finished junior-high-school. XD (22 cases, 48.9%) was the most com mon cause of dementia, followed by VaD (11 cases, 24.4%) and mixed dem entia (MIX; 5 cases, 11.1%). Old age and being female were significant high risk factors for AD. Medical history indicated that stroke and h ypertension were significant risk factors for VaD. A relatively high p revalence of dementia was observed in this study, probably because we assessed neurobehavior in great detail. Although AD was the leading ca use of dementia in tile present population sample, VaD and MIX also co mprised an important proportion, reflecting the high prevalence of str oke in Taiwan. Older women had high risk for AD, not for VaD; and thos e with a history of stroke and hypertension had high risk for VaD, not for AD.