title: Exportation and Validation of Latent Constructs for Dementia Case Finding in a Mexican American Population-based Cohort.
abstract: BACKGROUND
  The latent variable "δ" has been validated as a dementia phenotype. δ can be extracted from Spearman's general intelligence factor "g" in any data set that contains measures of cognition and instrumental activities of daily living (IADL). We used δ composites ("d-scores") to estimate the prevalence of dementia in the Hispanic Established Population for Epidemiological Studies in the Elderly (H-EPESE).
  
  
  METHODS
  δ was constructed from Mini-Mental State Examination, a clock-drawing task (CLOX), and IADL. δ's H-EPESE factor weights were validated in the well-characterized Texas Alzheimer's Research and Care Consortium (TARCC). Optimal thresholds for the discrimination between "Alzheimer's disease" (AD) versus normal controls (NCs) were determined by receiver operating characteristic curve. Those thresholds were used to estimate the prevalence of dementia in H-EPESE.
  
  
  RESULTS
  Each δ homolog fits its source's data well. d-scores were strongly associated with Clinical Dementia Rating scale Sum of Boxes (r = .74-.85, all p < .001], and accurately distinguished AD cases from NCs, in both Mexican Americans (MAs) and non-Hispanic Whites (NHWs) [c = 0.94-0.96]. The TARCC MA threshold estimated the prevalence of dementia at 21.4% in H-EPESE. The NHW threshold estimated the prevalence of dementia at 21.0%.
  
  
  CONCLUSIONS
  It is possible to export δ composites from populations to well-characterized cohorts for validation.
authors.affiliation: Department of Psychiatry, University of Texas Health Science Center, San Antonio.|Audie L. Murphy Division GRECC, South Texas Veterans' Health System, San Antonio.|Department of Family and Community Medicine, University of Texas Health Science Center, San Antonio.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Royall
authors.affiliation: Department of Family and Community Medicine, University of Texas Health Science Center, San Antonio.
authors.forename: Raymond F
authors.initials: RF
authors.lastname: Palmer
authors.affiliation: Division of Social and Behavioral Sciences, Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston.
authors.forename: Kyriakos S
authors.initials: KS
authors.lastname: Markides
mesh_terms: D000203:Activities of Daily Living / Q000145:classification* / Q000523:psychology; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000208:ethnology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000208:ethnology; D005260:Female; D006801:Humans; D007360:Intelligence; D008137:Longitudinal Studies; D008297:Male; D008609:Mental Status Schedule / Q000706:statistics & numerical data*; D017058:Mexican Americans / Q000523:psychology*; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000706:statistics & numerical data*; D012372:ROC Curve; D015203:Reproducibility of Results; D015206:Southwestern United States; D018709:Statistics, Nonparametric; D044465:White People / Q000523:psychology*
keywords: Aging; Cognition; Dementia; Functional status; g