Prevalence of cognitive impairment: results from the MRC trial of assessment and management of older people in the community.
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.


OBJECTIVE
we examined the prevalence of cognitive impairment in the UK and assessed associations with cognitive impairment.


METHODS
cross-sectional survey as part of a cluster randomised trial.


METHODS
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.
Rait
Greta
G
Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK. g.rait@pcps.ucl.ac.uk
Fletcher
Astrid
A
Smeeth
Liam
L
Brayne
Carol
C
Stirling
Susan
S
Nunes
Maria
M
Breeze
Elizabeth
E
Ng
Edmond Siu-Woon
ES
Bulpitt
Chris J
CJ
Jones
Dee
D
Tulloch
Alistair J
AJ
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008609:Mental Status Schedule; D015995:Prevalence; D012111:Residence Characteristics; D012737:Sex Factors; D006113:United Kingdom / Q000453:epidemiology