Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-04T21:10:19.636Z Has data issue: false hasContentIssue false

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

American Psychiatric Association 1994. Diagnostic and Statistical Manual of Mental Disorders: DSM-IV, 4th edn. Washington, DC: American Psychiatric Association.Google Scholar
Cacchione, P. Z., Powlishta, K. K., Grant, E. A., Buckles, V. D. and Morris, J. C. 2003. Accuracy of collateral source reports in very mild to mild dementia of the Alzheimer type. Journal of the American Geriatrics Society, 51, 819823.Google Scholar
Chiu, H. F. et al. 1998. Prevalence of dementia in Chinese elderly in Hong Kong. Neurology, 50, 10021009.Google Scholar
Chu, L. W., Chiu, K. C., Hui, S. L., Yu, G. K., Tsui, W. J. and Lee, P. W. 2000. The reliability and validity of the Alzheimer's Disease Assessment Scale Cognitive Subscale (ADAS-Cog) among the elderly Chinese in Hong Kong. Annual of the Academy of Medicine, Singapore, 29, 474485.Google ScholarPubMed
Dunn, G., Pickles, A., Tansella, M. and Vazquez-Barquero, J. L. 1999. Two-phase epidemiological surveys in psychiatric research. British Journal of Psychiatry, 174, 95100.CrossRefGoogle ScholarPubMed
Ferri, C. P., Prince, M. and Brayne, C. 2005. Global prevalence of dementia: a Delphi consensus study. Lancet, 366, 21122117.Google Scholar
Fisk, J. D., Merry, H. R. and Rockwood, K. 2003. Variations in case definition affect prevalence but not outcomes of mild cognitive impairment. Neurology, 11, 11791184.Google Scholar
Hughes, C. P., Berg, L., Danziger, W. L., Coben, L. A. and Martin, R. L. 1982. A new clinical scale for the staging of dementia. British Journal of Psychiatry, 140, 556572.Google Scholar
Lam, L. C., Lui, V. W., Tam, C.W. and Chiu, H. F. 2005. Subjective memory complaints in Chinese subjects with mild cognitive impairment and early Alzheimer's disease. International Journal of Geriatric Psychiatry, 20, 876882.Google Scholar
Lam, L. C., Ho, P., Lui, V. W. and Tam, C. W. 2006. Reduced semantic fluency as an additional screening tool for subjects with questionable dementia. Dementia and Related Geriatric Cognitive Disorders, 22, 159164.CrossRefGoogle ScholarPubMed
Larson, E. B. et al. 2006. Exercise is associated with reduced risk for incident dementia among persons 65 years of age and older. Annals of Internal Medicine, 144, 7381.CrossRefGoogle ScholarPubMed
Lim, W. S., Chong, M. S. and Sahadevan, S. 2007. Utility of the clinical dementia rating in Asian populations. Clinical Medicine and Research, 5, 6170.CrossRefGoogle ScholarPubMed
Liu, L., Guo, X. E., Zhou, Y. Q. and Xia, J. L. 2003. Prevalence of dementia in China. Dementia and Related Geriatric Cognitive Disorders, 15, 226230.Google Scholar
McKeith, I. G. et al. 2005. Diagnosis and management of dementia with Lewy bodies: third report of the DLB Consortium. Neurology, 65, 18631872.Google Scholar
McKhann, G., Drachman, D., Folstein, M., Katzman, R., Price, D. and Stadlan, E. M. 1984. Clinical diagnosis of Alzheimer's disease: report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer's Disease. Neurology, 34, 939944.CrossRefGoogle ScholarPubMed
Morris, J. C. et al. 2001. Mild cognitive impairment represents early-stage Alzheimer's disease. Archives of Neurology, 58, 397405.CrossRefGoogle Scholar
Panza, F. et al. 2005. Current epidemiology of mild cognitive impairment and other predementia syndromes. American Journal of Geriatric Psychiatry, 13, 633644.Google Scholar
Petersen, R. C. 2004. Mild Cognitive Impairment as a diagnostic entity. Journal of Internal Medicine, 256, 183194.Google Scholar
Prince, M. et al. 2003. Dementia diagnosis in developing countries: a cross-cultural validation study. Lancet, 361, 909917.Google Scholar
Qiu, C., De Ronchi, D. and Fratiglioni, L. 2007. The epidemiology of the dementias: an update. Current Opinion in Psychiatry, 20, 380385.Google Scholar
Román, G. C. et al. 1993. Vascular dementia: diagnostic criteria for research studies. Report of the NINDS-AIREN International Workshop. Neurology, 43, 250260.CrossRefGoogle ScholarPubMed
Sattin, R. W., Easley, K. A., Wolf, S. L., Chen, Y. and Kutner, M. H. 2005. Reduction in fear of falling through intense tai chi exercise training in older, transitionally frail adults. Journal of the American Geriatrics Society, 53, 11681178.CrossRefGoogle ScholarPubMed
Storandt, M., Grant, E. A., Miller, P. and Morris, J. 2002. Rates of progression in mild cognitive impairment and early Alzheimer's disease. Neurology, 59, 10341041.CrossRefGoogle ScholarPubMed
Teri, L. et al. 2003. Exercise plus behavioral management in patients with Alzheimer's disease – a randomized controlled trial. JAMA, 290, 20152022.Google Scholar
Thomas, G. N. et al. 2005. Effects of tai chi and resistance training on cardiovascular risk factors in elderly Chinese subjects: a 12-month longitudinal, randomized, controlled intervention study. Clinical Endocrinology, 63, 663669.Google Scholar
von Strauss, E., Viitanen, M., De Ronchi, D., Winblad, B. and Fratiglioni, L. 1999. Aging and the occurrence of dementia: findings from a population-based cohort with a large sample of nonagenarians. Archives of Neurology, 56, 587592.CrossRefGoogle ScholarPubMed
Wimo, A., Jonsson, L. and Winblad, B. 2006. An estimate of the worldwide prevalence and direct costs of dementia in 2003. Dementia and Related Geriatric Cognitive Disorders, 21, 175181.Google Scholar
Zhang, Z. X. et al. 2006. Socio-demographic variation of dementia subtypes in China: methodology and results of a prevalence study in Beijing, Chengdu, Shanghai, and Xian. Neuroepidemiology, 27, 177187.Google Scholar