title: Validity of the GAD-7 scale as an outcome measure of disability in patients with generalized anxiety disorders in primary care.
abstract: OBJECTIVE
  To explore the validity of the GAD-7 scale as an outcome measure of disability in primary care.
  
  
  METHODS
  A random sample of 212 subjects was recruited in primary care clinics; 50% diagnosed with generalized anxiety disorder (GAD) by DSM-IV criteria and 50% concurrent matched controls. The GAD-7, the Hamilton Anxiety Scale (HAM-A), and the abridged 12-item version of World Health Organization Disability Scale (WHO-DAS-II) were administered. The number of visits to primary care and specialty clinics was also recorded.
  
  
  RESULTS
  Strong and significant (p<0.001) correlations were found between GAD-7 and HAM-A (r=0.852) and WHO-DAS-II (r=0.704) scores, particularly for Participation in Society (r=0.741), Understanding and Communication (r=0.679), and Life Activities (0.638) dimensions. Moderate but significant correlations were also found between GAD-7 score and the number of visits to Primary Care (r=0.393) and Specialty clinics (r=0.373). In all cases, an overall relation was observed between GAD-7 severity levels and disability scores [F (3,208)=25.4, p<0.001] as assessed by the WHO-DAS II, with higher mean disability values related to higher severity levels.
  
  
  CONCLUSIONS
  The GAD-7 scale has been shown to highly correlate not only with specific anxiety but also with disability measures. It has been shown that more severe GAD levels correlate with higher disability states and tend to demand more health care attention. As the GAD-7 is self-administered and is not time consuming, this instrument could be a good choice to explore the level of patient disability in subjects with GAD in primary care settings.
authors.affiliation: Department of Methodology, School of Psychology, Universidad Autónoma de Madrid, Madrid, Spain; EACCOS Research Group, Madrid, Spain. miguel.ruiz@uam.es
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Ruiz
authors.forename: Enric
authors.initials: E
authors.lastname: Zamorano
authors.forename: Javier
authors.initials: J
authors.lastname: García-Campayo
authors.forename: Antonio
authors.initials: A
authors.lastname: Pardo
authors.forename: Olga
authors.initials: O
authors.lastname: Freire
authors.forename: Javier
authors.initials: J
authors.lastname: Rejas
mesh_terms: D000203:Activities of Daily Living; D001008:Anxiety Disorders / Q000175:diagnosis* / Q000523:psychology; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011320:Primary Health Care / Q000379:methods; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D015203:Reproducibility of Results; D013030:Spain