title: Screening for dementia in an Irish community sample using MMSE: a comparison of norm-adjusted versus fixed cut-points.
abstract: BACKGROUND
  The MMSE is a widely-used instrument in screening for dementia in the community. The traditional cut-point of <24/30 may be unsuitable for use in some settings, due to biases in age and education.
  
  
  OBJECTIVE
  This study aimed to investigate whether cut-points derived from age- and education-specific norms would improve the performance of the MMSE as a screening tool for dementia and cognitive impairment in an Irish community setting, potentially reducing the number of onward referrals. A secondary aim was to obtain score norms in an Irish sample.
  
  
  METHODS
  One thousand one hundred and fifteen people aged over 65 (mean age 74.8+/-6.8 years; 68% female) were assessed in their own homes, using MMSE (world) and the AGECAT computerised diagnostic system for mental illness in the elderly. The performance of the MMSE in identifying case- and sub-case-level dementia was investigated using cut-points of <24 and <23, as well as adjusted cut-points based on published norms and norms derived from the Irish sample.
  
  
  RESULTS
  Published norms did not prove useful in improving screening accuracy. Cut-points based on 10th percentile Irish norms and the <23 cut-point performed comparably well, both yielding 93% specificity, with overall accuracy of 90% and 91% respectively (as sensitivity was higher for the <23 cut-point).
  
  
  CONCLUSIONS
  Locally-derived norms yielded better screening accuracy than did published norms or the traditional <24 cut-point. The importance of selecting an appropriate percentile cut-off when using norms is discussed. The best results were obtained with a simple <23 cut-point, and this may be optimal when screening for dementia in an Irish community setting.
authors.affiliation: Mercer's Institute for Research on Ageing, St James's Hospital, Dublin 8, Ireland. bredacullen@dublin.com
authors.forename: Breda
authors.initials: B
authors.lastname: Cullen
authors.forename: Sabina
authors.initials: S
authors.lastname: Fahy
authors.forename: Conal J
authors.initials: CJ
authors.lastname: Cunningham
authors.forename: Robert F
authors.initials: RF
authors.lastname: Coen
authors.forename: Irene
authors.initials: I
authors.lastname: Bruce
authors.forename: Elaine
authors.initials: E
authors.lastname: Greene
authors.forename: Davis
authors.initials: D
authors.lastname: Coakley
authors.forename: J Bernard
authors.initials: JB
authors.lastname: Walsh
authors.forename: Brian A
authors.initials: BA
authors.lastname: Lawlor
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003704:Dementia / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007494:Ireland; D008297:Male; D008403:Mass Screening / Q000379:methods* / Q000592:standards; D008609:Mental Status Schedule / Q000592:standards*; D012015:Reference Standards; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric