title: Psychometric evaluation of the Generalized Anxiety Disorder Screener GAD-7, based on a large German general population sample.
abstract: The Generalized Anxiety Disorder Scales GAD-7 and GAD-2 are instruments for the assessment of anxiety. The aims of this study are to test psychometric properties of these questionnaires, to provide normative values, and to investigate associations with sociodemographic factors, quality of life, psychological variables, and behavioral factors.
  
  
  
  A German community sample (n=9721) with an age range of 18-80 years was surveyed using the GAD-7 and several other questionnaires.
  
  
  
  Confirmatory factor analyses confirmed the unidimensionality and measurement invariance of the GAD-7 across age and gender. Females were more anxious than males (mean scores: M=4.07 vs. M=3.01; effect size: d=0.33). There was no linear age trend. A total of 5.9% fulfilled the cut-off criterion of 10 and above. Anxiety was correlated with low quality of life, fatigue, low habitual optimism, physical complaints, sleep problems, low life satisfaction, low social support, low education, unemployment, and low income. Cigarette smoking and alcohol consumption were also associated with heightened anxiety, especially in women. When comparing the GAD-7 (7 items) with the ultra-short GAD-2 (2 items), the GAD-7 instrument was superior to the GAD-2 regarding several psychometric criteria.
  
  
  
  The response rate (33%) was low. Because of the cross-sectional character of the study, causal conclusions cannot be drawn. A further limitation is the lack of a gold standard for diagnosing anxiety.
  
  
  
  The GAD-7 can be recommended for use in clinical research and routine.
authors.affiliation: Department of Medical Psychology and Medical Sociology, University of Leipzig, Leipzig, Germany. Electronic address: Andreas.Hinz@medizin.uni-leipzig.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hinz
authors.affiliation: Department of Child and Adolescent Psychiatry, Psychotherapy, and Psychosomatics, University of Leipzig, Leipzig, Germany.
authors.forename: Annette M
authors.initials: AM
authors.lastname: Klein
authors.affiliation: Department of Medical Psychology and Medical Sociology, University of Leipzig, Leipzig, Germany; Clinic for Psychosomatic Medicine and Psychotherapy, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
authors.forename: Elmar
authors.initials: E
authors.lastname: Brähler
authors.affiliation: Department of Medical Psychology and Medical Sociology, University of Leipzig, Leipzig, Germany.
authors.forename: Heide
authors.initials: H
authors.lastname: Glaesmer
authors.affiliation: Institute of Social Medicine, Occupational Health, and Public Health, University of Leipzig, Leipzig, Germany; LIFE - Leipzig Research Center for Civilization Diseases, University of Leipzig, Leipzig, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Luck
authors.affiliation: Institute of Social Medicine, Occupational Health, and Public Health, University of Leipzig, Leipzig, Germany.
authors.forename: Steffi G
authors.initials: SG
authors.lastname: Riedel-Heller
authors.affiliation: LIFE - Leipzig Research Center for Civilization Diseases, University of Leipzig, Leipzig, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Wirkner
authors.affiliation: Leipzig University Medical Center, Integrated Research and Treatment Center Adiposity Diseases, University of Leipzig, Leipzig, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Hilbert
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000523:psychology; D001008:Anxiety Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D003430:Cross-Sectional Studies; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D000073222:Patient Health Questionnaire / Q000592:standards*; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000523:psychology; D012959:Socioeconomic Factors; D040701:Stress Disorders, Traumatic, Acute; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Anxiety; Epidemiology; General population; Normative values