Research Paper |
Prevalence of cognitive impairment: results from the MRC trial of assessment and management of older people in the community
1 Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
2 Institute of Public Health, University of Cambridge, Cambridge, UK
3 Section of Care of the Elderly, Imperial College School of Medicine, Hammersmith Campus, London, UK
4 University Department of Geriatric Medicine, Llandough Hospital, Penarth, Cardiff, UK
5 Unit of Health Care Epidemiology, Institute of Health Sciences, University of Oxford, Oxford, UK
Address correspondence to: G. Rait. Fax: (+44) 207 794 1224. Email: g.rait{at}pcps.ucl.ac.uk
Abstract
Background: cognitive impairment is an important part of the diagnostic criteria for dementia. The Mini-Mental State Examination (MMSE) is recommended to test for cognitive impairment and to monitor medication response.
Objectives: we examined the prevalence of cognitive impairment in the UK and assessed associations with cognitive impairment.
Design: cross-sectional survey as part of a cluster randomised trial.
Subjects: representative sample of people aged 75 years and over.
Methods: all subjects had a detailed baseline health assessment including the MMSE.
Results: a total of 15,051 subjects completed the assessment (71.9%). Almost two-thirds of subjects were female (61.5%) and almost half were aged between 75 and 79 years (47.0%). The prevalence of cognitive impairment was 18.3% (95% confidence intervals (CI) = 16.0–20.9) at a cut-off of 23/24, and 3.3% (95% CI = 2.8–4.0) at 17/18. Those with impairment (MMSE 23/24) were significantly more likely to have hearing (odds ratio (OR) 1.7), vision (OR 1.7) and urinary incontinence problems (OR 1.3), have two or more falls in the previous 6 months (OR 1.4), and report poorer health (OR 1.9). Almost half the participants lived alone (n = 7,073; 47.0%) and of these almost one-fifth were impaired (MMSE 23/24; 19.4%).
Conclusions: there was a high prevalence of cognitive impairment. This representative sample demonstrates the potential burden of disease and service demands. It supports the need for a broader assessment of functioning as recommended by the National Service Framework for Older People, particularly in people with cognitive impairment.
Keywords: cognition disorders, aged, primary health care, elderly
Received September 3, 2004; Revision received December 6, 2004. accepted in revised form December 6, 2004.