Prevalence of very mild and mild dementia in community-dwelling older Chinese people in Hong Kong.
BACKGROUND
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.
Lam
Linda C W
LC
Department of Psychiatry, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, The People's Republic of China. cwlam@cuhk.edu.hk
Tam
Cindy W C
CW
Lui
Victor W C
VW
Chan
W C
WC
Chan
Sandra S M
SS
Wong
Sunny
S
Wong
Ada
A
Tham
M K
MK
Ho
K S
KS
Chan
W M
WM
Chiu
Helen F K
HF
D017677:Age Distribution; D000368:Aged; D044466:Asian People / Q000523:psychology* / Q000706:statistics & numerical data; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D003625:Data Collection; D003704:Dementia / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004522:Educational Status; D015444:Exercise; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D008875:Middle Aged; D015995:Prevalence; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012307:Risk Factors; D012720:Severity of Illness Index