title: Clinical Dementia Rating independently predicted conversion to dementia in a cohort of urban elderly in Brazil.
abstract: BACKGROUND
  Dementia is a major public health problem in aging populations. The Clinical Dementia Rating (CDR) classifies the severity of dementia and identifies borderline cases that supposedly have higher rates of conversion to dementia. This study aims to verify the dementia conversion rate (CR) in a subsample of an elderly cohort (70+ free of the disease), and to identify risk factors, determining whether CDR is able to predict which individuals have high likelihood of converting.
  
  
  METHODS
  A subsample of 156 participants was clinically evaluated for dementia at baseline in which 80 patients without dementia were reassessed after 2.6 years on average to verify the conversion. The CR was analyzed according to demographic, health variables, and CDR classification at baseline, using the Poisson regression method in univariate and multivariate analyses, with exposure time as an offset variable (person-years).
  
  
  RESULTS
  From those re-evaluated, 50% had CDR = 0 and a CR of 38.1/1,000 person-years and the other 50%, CDR = 0.5 (70% with sum of boxes scores ≤1, CR = 145.4/1,000 person-years and 30% > 1, CR = 216.8/1,000 person-years). CR was 91.3/1,000 person-years on average. In the multivariate analysis, when compared with those with CDR = 0, the hazard ratio of those with CDR = 0.5 was 3.82; and for those with CDR = 0.5 and sum of boxes scores >1, 5.69.
  
  
  CONCLUSIONS
  Conversion rate to dementia was significantly higher among those with CDR = 0.5 and even higher for those whose sum of boxes scores was >1. Therefore, CDR was able to predict which individuals had a higher likelihood of converting to dementia.
authors.affiliation: Departamento de Medicina Preventiva, Universidade Federal de São Paulo, São Paulo, Brazil. robeyca@terra.com.br
authors.forename: Maria Beatriz Marcondes Macedo
authors.initials: MB
authors.lastname: Montaño
authors.forename: Solange
authors.initials: S
authors.lastname: Andreoni
authors.forename: Luiz Roberto
authors.initials: LR
authors.lastname: Ramos
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D015897:Comorbidity; D003704:Dementia / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000523:psychology; D004522:Educational Status; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D054624:Health Status Disparities; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D062706:Prodromal Symptoms; D011379:Prognosis; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012307:Risk Factors