title: Prevalence of cognitive impairment: results from the MRC trial of assessment and management of older people in the community.
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.
  
  
  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.
authors.affiliation: 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
authors.forename: Greta
authors.initials: G
authors.lastname: Rait
authors.forename: Astrid
authors.initials: A
authors.lastname: Fletcher
authors.forename: Liam
authors.initials: L
authors.lastname: Smeeth
authors.forename: Carol
authors.initials: C
authors.lastname: Brayne
authors.forename: Susan
authors.initials: S
authors.lastname: Stirling
authors.forename: Maria
authors.initials: M
authors.lastname: Nunes
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Breeze
authors.forename: Edmond Siu-Woon
authors.initials: ES
authors.lastname: Ng
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Bulpitt
authors.forename: Dee
authors.initials: D
authors.lastname: Jones
authors.forename: Alistair J
authors.initials: AJ
authors.lastname: Tulloch
mesh_terms: 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