title: Operationalizing the Diagnostic Criteria for Mild Cognitive Impairment: The Salience of Objective Measures in Predicting Incident Dementia.
abstract: OBJECTIVE
  Mild cognitive impairment (MCI) is considered an intermediate stage between normal aging and dementia. It is diagnosed in the presence of subjective cognitive decline and objective cognitive impairment without significant functional impairment, although there are no standard operationalizations for each of these criteria. The objective of this study is to determine which operationalization of the MCI criteria is most accurate at predicting dementia.
  
  
  METHODS
  Six-year longitudinal study, part of the Sydney Memory and Ageing Study.
  
  
  METHODS
  Community-based.
  
  
  METHODS
  873 community-dwelling dementia-free adults between 70 and 90 years of age. Persons from a non-English speaking background were excluded.
  
  
  METHODS
  Seven different operationalizations for subjective cognitive decline and eight measures of objective cognitive impairment (resulting in 56 different MCI operational algorithms) were applied. The accuracy of each algorithm to predict progression to dementia over 6 years was examined for 618 individuals.
  
  
  RESULTS
  Baseline MCI prevalence varied between 0.4% and 30.2% and dementia conversion between 15.9% and 61.9% across different algorithms. The predictive accuracy for progression to dementia was poor. The highest accuracy was achieved based on objective cognitive impairment alone. Inclusion of subjective cognitive decline or mild functional impairment did not improve dementia prediction accuracy.
  
  
  CONCLUSIONS
  Not MCI, but objective cognitive impairment alone, is the best predictor for progression to dementia in a community sample. Nevertheless, clinical assessment procedures need to be refined to improve the identification of pre-dementia individuals.
authors.affiliation: Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia; Dementia Collaborative Research Centre-Assessment and Better Care, School of Psychiatry, University of New South Wales, Sydney, Australia; Academic Department for Old Age Psychiatry, Prince of Wales Hospital, Randwick, Australia. Electronic address: h.brodaty@unsw.edu.au.
authors.forename: Henry
authors.initials: H
authors.lastname: Brodaty
authors.affiliation: Dementia Collaborative Research Centre-Assessment and Better Care, School of Psychiatry, University of New South Wales, Sydney, Australia.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Aerts
authors.affiliation: Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia.
authors.forename: John D
authors.initials: JD
authors.lastname: Crawford
authors.affiliation: Dementia Collaborative Research Centre-Assessment and Better Care, School of Psychiatry, University of New South Wales, Sydney, Australia.
authors.forename: Megan
authors.initials: M
authors.lastname: Heffernan
authors.affiliation: Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia; Neuropsychiatric Institute, Prince of Wales Hospital, Randwick, Australia.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Kochan
authors.affiliation: Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia; Department of Developmental Disability Neuropsychiatry, School of Psychiatry, University of New South Wales, Sydney, Australia.
authors.forename: Simone
authors.initials: S
authors.lastname: Reppermund
authors.affiliation: Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia.
authors.forename: Kristan
authors.initials: K
authors.lastname: Kang
authors.affiliation: Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia.
authors.forename: Kate
authors.initials: K
authors.lastname: Maston
authors.affiliation: Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia; Academic Department for Old Age Psychiatry, Prince of Wales Hospital, Randwick, Australia.
authors.forename: Brian
authors.initials: B
authors.lastname: Draper
authors.affiliation: Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia; Department of Developmental Disability Neuropsychiatry, School of Psychiatry, University of New South Wales, Sydney, Australia.
authors.forename: Julian N
authors.initials: JN
authors.lastname: Trollor
authors.affiliation: Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia; Academic Department for Old Age Psychiatry, Prince of Wales Hospital, Randwick, Australia.
authors.forename: Perminder S
authors.initials: PS
authors.lastname: Sachdev
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D060825:Cognitive Dysfunction / Q000150:complications / Q000175:diagnosis*; D003704:Dementia / Q000150:complications / Q000175:diagnosis*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests
keywords: Mild cognitive impairment; cognitive impairment; dementia conversion; dementia prediction; diagnostic criteria