title: Validation of a short cognitive tool for the screening of dementia in elderly people with low educational level.
abstract: OBJECTIVE
  To validate the 'Prueba Cognitiva de Leganés' (PCL) as a screening tool for cognitive impairment in elderly people with little formal education.
  
  
  METHODS
  The PCL is a simple cognitive test with 32 items that includes two scores of orientation and memory and a global score of 0-32 points. It was applied to a population sample of 527 elderly people over 70 with low educational level, who were independently diagnosed by consensus between two neurologists as having normal cognitive function, age associated cognitive decline (AACD, IPA-OMS criteria) or dementia (DSM-IV criteria). Individuals with severe visual or hearing defects and those who rejected the exam were excluded from the study. The PCL was validated in a sample of 375 individuals: 300 normal, 42 with AACD and 33 with dementia. The sensitivity, specificity, accuracy and likelihood ratios, as well as the ROC curves for dementia and for AACD-dementia, were calculated. The confounding effect of sociodemographic variables was assessed by logistic regression analysis and convergent validity by partial correlations of the PCL with other cognitive tests. Inter-rater reliability was evaluated with the intraclass correlation coefficient.
  
  
  RESULTS
  The PCL identified dementia (cut-off < or =22) and AACD-dementia (cut-off < or =26), with the following diagnostic parameters, respectively: sensitivity 93.9%-80%, specificity 94.7%-84.3%, positive likelihood ratio 17.8-5.1, negative likelihood ratio 0.06-0.24, and accuracy 94.6%-83.4%. The areas under the ROC curve were 0.985 (95% Confidence Intervals (CI) 0.967-0.995) and 0.904 (95% CI: 0.870-0.932) respectively. The intraclass correlation coefficient was 0.79 (0.74-0.83).
  
  
  CONCLUSIONS
  The PCL is a simple instrument, which is both valid and reliable, for the screening of dementia in population samples of individuals with low educational level. This instrument could be useful in primary health care.
authors.affiliation: Centro Universitario de Salud Pública, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: María Jesús García
authors.initials: MJ
authors.lastname: De Yébenes
authors.forename: Angel
authors.initials: A
authors.lastname: Otero
authors.forename: María Victoria
authors.initials: MV
authors.lastname: Zunzunegui
authors.forename: Angel
authors.initials: A
authors.lastname: Rodríguez-Laso
authors.forename: Fernando
authors.initials: F
authors.lastname: Sánchez-Sánchez
authors.forename: Teodoro
authors.initials: T
authors.lastname: Del Ser
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000175:diagnosis*; D003704:Dementia / Q000523:psychology*; D004522:Educational Status; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000592:standards; D015588:Observer Variation; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012680:Sensitivity and Specificity