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

Int Psychogeriatr. 2008 Feb;20(1):135-48. doi: 10.1017/S1041610207006199. Epub 2007 Sep 25.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Distribution
  • Aged
  • Asian People / psychology*
  • Asian People / statistics & numerical data
  • Cognition Disorders / diagnosis*
  • Cognition Disorders / epidemiology
  • Cognition Disorders / psychology
  • Data Collection
  • Dementia / diagnosis*
  • Dementia / epidemiology
  • Dementia / psychology
  • Diagnostic and Statistical Manual of Mental Disorders
  • Educational Status
  • Exercise
  • Female
  • Hong Kong / epidemiology
  • Humans
  • Logistic Models
  • Male
  • Memory Disorders / diagnosis*
  • Memory Disorders / epidemiology
  • Memory Disorders / psychology
  • Middle Aged
  • Prevalence
  • Psychiatric Status Rating Scales / statistics & numerical data
  • Risk Factors
  • Severity of Illness Index