Psychometric Properties of the Generalized Anxiety Disorder Scale-7 (GAD-7) in Outpatients with Anxiety and Mood Disorders

Abstract

This study examined the psychometric properties of the Generalized Anxiety Disorder Scale-7 (GAD-7) in a sample of 536 outpatients presenting at a specialty clinic for anxiety and mood disorders. A confirmatory factor analysis (CFA) was used to test the unidimensionality of the GAD-7. This model did not fit the data well. The CFA solution was respecified correlating residuals among items assessing somatic symptoms. This respecified model fit the data well. A series of multiple-groups CFAs determined that the measurement properties of the GAD-7 were invariant between sexes. Scale reliability estimates of the GAD-7 were favorable for the full sample, and for males and females. Sensitivity and specificity could not be balanced at any cut-point. Findings attest to the value of this instrument as a dimensional indicator of GAD severity rather than a screening tool for the presence or absence of the disorder in outpatients with anxiety and mood disorders.

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Notes

  1. 1.

    To address this issue, we tested the relationship between the GAD-7 and high negative affect/neuroticism using the Neuroticism scale from the NEO Five Factor Inventory (NFFI-N). Although the NFFI-N was moderately correlated with the GAD-7 factor (r = .56), inferential tests of the differential magnitude of relationships indicated that the GAD-7 factor was more strongly correlated with the DASS-S (r = .68, z = 4.50, p < .001) and the PSWQ (r = .66, z = 3.93, p < .001) than the NFFI-N. Although providing support for the convergent validity of the GAD-7, the results also indicated that the GAD-7 factor was more strongly correlated with the NFFI-N than with the DASS-D (r = .47, z = 2.97, p < .01) and the OCD-R (r = .42, z = 3.40, p < .001) in accord with the notion that GAD is more closely related to neuroticism than other emotional disorders (e.g., major depressive disorder, OCD). The test of the differential magnitude of correlations involving the GAD-7 and NFFI-N with the DASS-A was not significant (r = .52, z = 0.85).

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Correspondence to Lauren A. Rutter.

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Funding

This study was funded by the National Institute of Mental Health (Grant MH039096) to the second author. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Mental Health or the National Institutes of Health.

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Lauren A. Rutter declares that she has no conflict of interest. Timothy A. Brown declares that he has no conflict of interest.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

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Rutter, L.A., Brown, T.A. Psychometric Properties of the Generalized Anxiety Disorder Scale-7 (GAD-7) in Outpatients with Anxiety and Mood Disorders. J Psychopathol Behav Assess 39, 140–146 (2017). https://doi.org/10.1007/s10862-016-9571-9

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Keywords

  • GAD-7
  • Anxiety
  • Validity
  • Psychometrics
  • Clinical sample