Factor structure and construct validity of the Generalized Anxiety Disorder 7-item (GAD-7) among Portuguese college students

Abstract

The Generalized Anxiety Disorder 7-item (GAD- 7

The psychometric properties of the Generalized Anxiety Disorder scale (GAD-7) among Korean university students

“…The GAD-7 scale exhibited excellent internal consistency with this sample, as Cronbach's alpha was above .80. Other studies involving non-clinical and clinical samples in the United States, Iran, New England, Germany, Peru, and Portugal have similarly found Cronbach's alpha coefficients ranging from good to excellent [12][13][14][15]19]. Together, these findings suggest that the GAD-7 shows good internal consistency across different populations and languages.…”

“…Although the internal consistency of the GAD-7 has shown to be adequate across these studies (α = .85−.92) [9][10][11][12][13][14][15][16][17][18][19] and although the instrument demonstrated moderate to strong correlations with other related measures of depression and anxiety, evaluations of the one-dimensional nature of GAD-7 proposed by the original model have not been consistent in the research. For example, previous investigations of the factor structure of the GAD-7 have supported a one-factor solution with Western primary care patients [9], people with infertility [14], a Dutch web-based sample [17], and Portuguese college students [19]. Conversely, Beard and Björgvinsson [11] confirmed that the one-factor structure was not applicable among Western psychiatric samples.…”

“…The psychometric properties of the GAD-7 have also been evaluated in various populations of varying ages, including primary care samples [9], psychiatric patients [10,11], general adults [12], pregnant women [13], people with infertility [14], outpatients [15], multicultural populations [16,17], elderly [18], and college students [19]. Although the internal consistency of the GAD-7 has shown to be adequate across these studies (α = .85−.92) [9][10][11][12][13][14][15][16][17][18][19] and although the instrument demonstrated moderate to strong correlations with other related measures of depression and anxiety, evaluations of the one-dimensional nature of GAD-7 proposed by the original model have not been consistent in the research. For example, previous investigations of the factor structure of the GAD-7 have supported a one-factor solution with Western primary care patients [9], people with infertility [14], a Dutch web-based sample [17], and Portuguese college students [19].…”

“…Some of these investigations into the original one-factor structure of the GAD-7, however, made modifications to their models, such as allowing certain error terms to covary so as to attain a well-fitting model. Hence, an excellent or good fit of the one-factor structure has not been confirmed in psychiatric samples or in non-clinical communities of university students, limiting the acceptability of the GAD-7 as an alternative measure to detect GAD in an academic setting [19].…”

“…Since GAD is accompanied by symptoms of both an autonomic/physical and cognitive-emotional nature, which are included as diagnostic criteria for GAD-7, a one-dimensional approach to the construct may have implications for screening in community samples as well [19]. Accordingly, an independent assessment of items of a somatic/physical and cognitive-emotional nature related to the experience of GAD could be a way to identify and ensure proper treatment of this problem in the university setting [19]. Despite the encouraging psychometric results when the GAD-7 has been applied with various populations, the measure has remained untested with Korean university students.…”