title: Coordinated analysis of age, sex, and education effects on change in MMSE scores.
abstract: OBJECTIVE
  We describe and compare the expected performance trajectories of older adults on the Mini-Mental Status Examination (MMSE) across six independent studies from four countries in the context of a collaborative network of longitudinal studies of aging. A coordinated analysis approach is used to compare patterns of change conditional on sample composition differences related to age, sex, and education. Such coordination accelerates evaluation of particular hypotheses. In particular, we focus on the effect of educational attainment on cognitive decline.
  
  
  METHODS
  Regular and Tobit mixed models were fit to MMSE scores from each study separately. The effects of age, sex, and education were examined based on more than one centering point.
  
  
  RESULTS
  Findings were relatively consistent across studies. On average, MMSE scores were lower for older individuals and declined over time. Education predicted MMSE score, but, with two exceptions, was not associated with decline in MMSE over time.
  
  
  CONCLUSIONS
  A straightforward association between educational attainment and rate of cognitive decline was not supported. Thoughtful consideration is needed when synthesizing evidence across studies, as methodologies adopted and sample characteristics, such as educational attainment, invariably differ.
authors.affiliation: Department of Psychology, University of Victoria, British Columbia, Canada. piccinin@uvic.ca
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Piccinin
authors.forename: Graciela
authors.initials: G
authors.lastname: Muniz-Terrera
authors.forename: Sean
authors.initials: S
authors.lastname: Clouston
authors.forename: Chandra A
authors.initials: CA
authors.lastname: Reynolds
authors.forename: Valgeir
authors.initials: V
authors.lastname: Thorvaldsson
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.forename: Dorly J H
authors.initials: DJ
authors.lastname: Deeg
authors.forename: Boo
authors.initials: B
authors.lastname: Johansson
authors.forename: Andrew
authors.initials: A
authors.lastname: Mackinnon
authors.forename: Avron
authors.initials: A
authors.lastname: Spiro
authors.forename: John M
authors.initials: JM
authors.lastname: Starr
authors.forename: Ingmar
authors.initials: I
authors.lastname: Skoog
authors.forename: Scott M
authors.initials: SM
authors.lastname: Hofer
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology / Q000523:psychology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology*; D004522:Educational Status; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D012737:Sex Factors; D055815:Young Adult