title: Validation and standardization of the Generalized Anxiety Disorder Screener (GAD-7) in the general population.
abstract: BACKGROUND
  The 7-item Generalized Anxiety Disorder Scale (GAD-7) is a practical self-report anxiety questionnaire that proved valid in primary care. However, the GAD-7 was not yet validated in the general population and thus far, normative data are not available.
  
  
  OBJECTIVE
  To investigate reliability, construct validity, and factorial validity of the GAD-7 in the general population and to generate normative data.
  
  
  METHODS
  Nationally representative face-to-face household survey conducted in Germany between May 5 and June 8, 2006.
  
  
  METHODS
  Five thousand thirty subjects (53.6% female) with a mean age (SD) of 48.4 (18.0) years.
  
  
  METHODS
  The survey questionnaire included the GAD-7, the 2-item depression module from the Patient Health Questionnaire (PHQ-2), the Rosenberg Self-Esteem Scale, and demographic characteristics.
  
  
  RESULTS
  Confirmatory factor analyses substantiated the 1-dimensional structure of the GAD-7 and its factorial invariance for gender and age. Internal consistency was identical across all subgroups (alpha = 0.89). Intercorrelations with the PHQ-2 and the Rosenberg Self-Esteem Scale were r = 0.64 (P < 0.001) and r = -0.43 (P < 0.001), respectively. As expected, women had significantly higher mean (SD) GAD-7 anxiety scores compared with men [3.2 (3.5) vs. 2.7 (3.2); P < 0.001]. Normative data for the GAD-7 were generated for both genders and different age levels. Approximately 5% of subjects had GAD-7 scores of 10 or greater, and 1% had GAD-7 scores of 15 or greater.
  
  
  CONCLUSIONS
  Evidence supports reliability and validity of the GAD-7 as a measure of anxiety in the general population. The normative data provided in this study can be used to compare a subject's GAD-7 score with those determined from a general population reference group.
authors.affiliation: Department of Psychosomatic Medicine and Psychotherapy, University Medical Center Hamburg-Eppendorf and Hamburg-Eilbek (Schön Clinics), Hamburg, Germany. b.loewe@uke.unihamburg.de
authors.forename: Bernd
authors.initials: B
authors.lastname: Löwe
authors.forename: Oliver
authors.initials: O
authors.lastname: Decker
authors.forename: Stefanie
authors.initials: S
authors.lastname: Müller
authors.forename: Elmar
authors.initials: E
authors.lastname: Brähler
authors.forename: Dieter
authors.initials: D
authors.lastname: Schellberg
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Herzog
authors.forename: Philipp Yorck
authors.initials: PY
authors.lastname: Herzberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001008:Anxiety Disorders / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011320:Primary Health Care; D011594:Psychometrics / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires