title: Validity of the Brazilian version of the Geriatric Depression Scale (GDS) among primary care patients.
abstract: BACKGROUND
  The aim of the present study was to determine the validity of the Brazilian version of the Geriatric Depression Scale (GDS) with 30 (GDS-30), 15 (GDS-15), 10 (GDS-10), 4 (GDS-4) and 1 (GDS-1) items and to calculate the optimum cutoff points for identifying depression among elderly primary care subjects.
  
  
  METHODS
  A cross-sectional study was carried out involving 220 elderly patients recruited from four primary care clinics in northeastern Brazil. The following measurements were obtained: sociodemographic variables, Katz scale of independence in activities of daily living, and the GDS with 30, 15, 10, 4 and 1 item(s). A psychiatrist blinded to the results of the GDS applied the mood module of the Structured Clinical Interview for the DSM-IV for the diagnosis of major depressive episodes as the "gold standard."
  
  
  RESULTS
  The use of the cut-off point of 10/11 for the GDS-30 produced sensitivity and specificity rates of 92.0% (95% CI: 70-98) and 79% (95% CI: 73-85), respectively. The positive predictive value (PPV) and the negative predictive value (NPV) were 49% and 98%, respectively. The optimum cut-off point for the GDS-15 was 4/5, at which sensitivity was 87% (95% CI: 71-95) and specificity was 82% (95% CI: 76-91), PPV was 51% and NPV was 97%. At the cut-off point of 3/4 the sensitivity, specificity, PPV and NPV for the GDS-10 were 76% (95% CI: 60-89), 81% (95% CI: 75-87), 46% (95% CI: 33-59%), and 94% (95% CI 89-97%), respectively. The optimum cut-off point for the GDS-4 was 0/1, at which sensitivity was 84% (95% CI: 68-93%); specificity was 75% (95% CI; 68-91%); PPV was 41% and NPV was 96%. For the GDS-1, sensitivity was 47%, specificity was 96%; PPV was 69% and NPV was 90%.
  
  
  CONCLUSIONS
  The GDS-30, GDS-15, GDS-10 and GDS-4 proved to be good screening instruments for depression in primary care clinics in Brazil, whereas the GDS-1 failed to perform adequately.
authors.affiliation: University of Fortaleza, Division of Mental Health, Fortaleza, CE, Brazil.
authors.forename: Milena Sampaio
authors.initials: MS
authors.lastname: Castelo
authors.forename: João M
authors.initials: JM
authors.lastname: Coelho-Filho
authors.forename: André F
authors.initials: AF
authors.lastname: Carvalho
authors.forename: José W O
authors.initials: JW
authors.lastname: Lima
authors.forename: Jamile C S
authors.initials: JC
authors.lastname: Noleto
authors.forename: Kérsia G
authors.initials: KG
authors.lastname: Ribeiro
authors.forename: José I
authors.initials: JI
authors.lastname: Siqueira-Neto
mesh_terms: D000368:Aged; D001938:Brazil / Q000453:epidemiology; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology; D003866:Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011320:Primary Health Care; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires