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Prevalence of very mild and mild dementia in community-dwelling older Chinese people in Hong Kong

Published online by Cambridge University Press:  01 February 2008

Linda C. W. Lam*
Affiliation:
Department of Psychiatry, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, The People's Republic of China
Cindy W. C. Tam
Affiliation:
Department of Psychiatry, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, The People's Republic of China
Victor W. C. Lui
Affiliation:
Department of Psychiatry, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, The People's Republic of China
W. C. Chan
Affiliation:
Castle Peak Hospital, Tuen Mum, Hong Kong SAR, The People's Republic of China
Sandra S. M. Chan
Affiliation:
Department of Psychiatry, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, The People's Republic of China
Sunny Wong
Affiliation:
Department of Psychiatry, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, The People's Republic of China
Ada Wong
Affiliation:
Elderly Health Service, Department of Health, Hong Kong SAR, The People's Republic of China
M. K. Tham
Affiliation:
Elderly Health Service, Department of Health, Hong Kong SAR, The People's Republic of China
K. S. Ho
Affiliation:
Elderly Health Service, Department of Health, Hong Kong SAR, The People's Republic of China
W. M. Chan
Affiliation:
Elderly Health Service, Department of Health, Hong Kong SAR, The People's Republic of China
Helen F. K. Chiu
Affiliation:
Department of Psychiatry, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, The People's Republic of China
*
Correspondence should be addressed to: Dr. Linda C. W. Lam, Department of Psychiatry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, The People's Republic of China. Phone: +852 26076026; Fax: +852 26671255. Email: [email protected].

Abstract

Introduction: In this report, the results of a household survey were used to examine the prevalence of very mild and mild dementia in Chinese older persons in Hong Kong.

Methods: The study adopted a two-phase design. At Phase 1, 6100 subjects were screened using the Cantonese version of the Mini-mental State Examination (MMSE) and a short memory inventory. At Phase 2, 2073 subjects were screened positive and 737 were evaluated by psychiatrists. Clinical Dementia Rating (CDR) and cognitive assessment were used for diagnosis of dementia. Very mild dementia (VMD) was defined as a global CDR of 0.5, with memory and non-memory subscale scores of 0.5 or more. Mild dementia was classified for subjects with a CDR of 1.

Results: The overall prevalence of VMD and mild dementia for persons aged 70 years or above was 8.5% (95%CI: 7.4–9.6) and 8.9% (95%CI: 7.8–10.0) respectively. Among subjects with clinical dementia, 84.6% had mild (CDR1) dementia. Logistic regression analyses revealed that older age, lower educational level and significant cerebrovascular risk factors were risk factors for dementia, while regular physical exercise was a protective factor for dementia.

Conclusions: A sizable proportion of community-living subjects suffered from milder forms of dementia. They represent a high risk for early intervention to reduce potential physical and psychiatric morbidity.

Type
Research Article
Copyright
Copyright © International Psychogeriatric Association 2007

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