title: The δ latent dementia phenotype in the uniform data set: Cross-validation and extension.
abstract: OBJECTIVE
  Royall and colleagues identified a latent dementia phenotype, "δ", reflecting the "cognitive correlates of functional status." We sought to cross-validate and extend these findings in a large clinical case series of adults with and without dementia.
  
  
  METHODS
  A confirmatory factor analysis (CFA) model for δ was fit to National Alzheimer's Coordinating Center data (n = 26,068). Factor scores derived from δ were compared with the Clinical Dementia Rating Sum of Boxes (CDR-SB) and to clinically diagnosed dementia. A longitudinal parallel-process growth model compared changes in δ with changes in CDR-SB over 6 annual evaluations.
  
  
  RESULTS
  The CFA model fit well; CFI = 0.971, RMSEA = 0.070. Factor scores derived from δ discriminated between demented and nondemented participants with an area under the curve of .96. The growth model also fit well, CFI = 0.969, RMSEA = 0.032.
  
  
  CONCLUSIONS
  The δ construct represents a novel approach to measuring dementia-related changes and has potential to improve cognitive assessment of neurodegenerative diseases.
authors.affiliation: Department of Psychology, University of Colorado, Colorado Springs.
authors.forename: Brandon E
authors.initials: BE
authors.lastname: Gavett
authors.affiliation: Department of Psychology, University of Colorado, Colorado Springs.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Vudy
authors.affiliation: Department of Psychology, University of Colorado, Colorado Springs.
authors.forename: Mary
authors.initials: M
authors.lastname: Jeffrey
authors.affiliation: Department of Psychology, University of Colorado, Colorado Springs.
authors.forename: Samantha E
authors.initials: SE
authors.lastname: John
authors.affiliation: Department of Psychology, University of Colorado, Colorado Springs.
authors.forename: Ashita S
authors.initials: AS
authors.lastname: Gurnani
authors.affiliation: Department of Psychology, University of Colorado, Colorado Springs.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Adams
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000523:psychology*; D003071:Cognition / Q000502:physiology*; D003704:Dementia / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype