作者
Zhanhui Gao,Bingyan Xie,Yue Fang,Jialiang Pan
摘要
Summary A survey of the prevalence of dementia among elderly was conducted in three different areas of Shanghai, the Peoples Republic of China. The DSM-III-R was used as diagnostic criteria. The prevalence of dementia in the whole sample was 4.21%: Alzheimer's disease (3.15%) and vascular dementia (0.85%). The prevalence increased with age: 1.78% among those aged 60-64, 3.92% among 70-74, 12.45% among 80 years and older. The prevalence was higher in women and in urban residents. The potential risk factors of dementia were formulated and discussed. Key Words: prevalence, senile dementia, Chinese INTRODUCTION In developed countries, the prevalence of severe dementia among persons aged 65 years and older has been estimated to be between 1.3% and 6.2%, with an average rate of about 4.5%. The prevalence of mild dementia has been reported to vary from 2.6% to 10.8%. The prevalence of dementia, mild and severe, was between 6.6% and 15.8% (Mortiner, et al. 1981: Shahavama, et al. 1986; Garland & Cross, 1982; Mortiner, 1983). In China, there have been limited epidemiological investigations on dementia among elderly. Previous papers have shown that among she aged population, 0.46% to 1.86% had dementia and the prevalence of Alzheimer's disease (AD) was between 0.07% to 0.66% (Chen, et al. 1987; Kuang & Zhao, 1981; Yan & Liu, 1988). We had conducted an epidemiology study of dementia among elderly in Shanghai and nearby areas from October to December 1990. Three Research units collaborated in the survey: Shanghai Mental Health Center, Shanghai Jiading County Mental Health Center, and Shanghai Zabei District Mental Health Center. METHODS The Mini-Mental State Examination (MMSE) (Folstein, et al. 1975), a brief screening tool with high validity, sensitivity and specialty, was used. The cut-off points used to identify probable cases of dementia were 17 for subjects with no education, 20 for elementary education, and 24 for those who received primary middle or above education respectively (Wang, et al 1989). CASE SCREENING: Twenty healthy elderly people were rated with MMSE by 14 psychiatrists. The concordance rate was 0.95. A stratified radom sampling method was used in a country, a town and a suburban area. A cohort of 4597 subjects aged 60 or above was investigated. 3779 subjects were interviewed by investigators. 1499 were male and 2280 were female (M:F=1:1.57). 1219 of them lived in urban district, 2045 lived in rural area and 515 in suburban area. DIAGNOSIS MAKING The elderly individuals scored lower than the cut-off points on MMSE were interviewed by 2 investigators. The diagnosis of senile dementia or Alzheimer's disease was made according to the DSM-III-R criteria (American Psychiatric Association, 1986). Hachinski Ischemic Scale (HIS) (Hachinski, 1978) was also used. From those 316 individuals scored higher than the cut-off points. About 10% were found meeting the criteria of dementia. RESULTS THE PREVALENCE OF DEMENTIA One hundred and fifty nine subjects met the DSM-III-R criteria of dementia. Seventy of them lived in city, 80 in countryside and 8 in small town. The prevalence of dementia in the city, countryside and small town were 5.74%, 3.90% and 1.55% respectively. There was statistically significant difference among the three areas ([X.sup.2] = 11.42, P SUBTYPES OF DEMENTIA The prevalence of senile dementia Alzheimer type (SDAT) in city was 1.9 times and 4.2 times of that in countryside and town (table 1}, while the figures of cerebrovascular dementia (CVD) were similar in city and countryside, but were higher than that in town. SEX, AGE AND DEMENTIA Among the 159 demented patients, 24 were male, 135 were female (Male: Female = 1:5.6). The prevalence of dementia among male and female are 1.60% and 5.92% respectively, and there was statistically significant difference between them ([X. …