Factorial Validity and Invariance of the 7-Item Generalized Anxiety Disorder Scale (GAD-7) Among Populations With and Without Self-Reported Psychiatric Diagnostic Status

Abstract

The 7-item Generalized Anxiety Disorder Scale (GAD-7) is commonly used to monitor anxiety symptoms. However, its factor structure has been inconsistent among competing models: unidimensional, two-dimensional, or higher order models. Additionally, it is unknown whether the scale has measurement invariance between populations with and without self-reported psychiatric diagnostic status. Participants were Japanese adults with self-reported anxiety disorder (AD; n = 479), self-reported AD and major depressive disorder (MDD; n = 314), or without self-reported psychiatric diagnostic status (self-reported non-MDD/AD; n = 654), who completed this questionnaire on the Internet. Confirmatory factor analyses showed the higher order model had similar fit indices to the unidimensional and two-dimensional factor models. For the higher order model of GAD-7, metric invariance was supported between the self-reported non-MDD/AD and self-reported AD status groups, and scalar invariance was supported between the self-reported AD status and self-reported AD with MDD status groups. Moreover, convergent and discriminant validity were consistent with previous findings in Western cultures. These results suggest that factor loadings are equivalent and the construct has the same meaning between the self-reported non-MDD/AD and self-reported AD status groups, and the total or sub-scale scores were comparable between self-reported AD status and self-reported AD with MDD status groups. The major limitation of this study is that the participants’ diagnoses were self-reported, not confirmed by clinical structured interview. Further studies that incorporate clinical structured interviews are needed.

Psychometric Properties of the Generalized Anxiety Disorder-7 and Generalized Anxiety Disorder-Mini in United States University Students

“…Similar findings also were reported for primary care patients (Jordan et al, 2017;Johnson et al, 2019), psychiatric patients (Dear et al, 2011;Kertz et al, 2013;Konkan et al, 2013;Rutter and Brown, 2017;Johnson et al, 2019), infertility patients (Omani-Samani et al, 2018), the general population in several countries (Konkan et al, 2013;Sousa et al, 2015;Hinz et al, 2017), adolescents (Tiirikainen et al, 2019), individuals receiving care in a traditional medicine department in China (Zeng et al, 2013), and in non-English speakers (Mills et al, 2014;Sousa et al, 2015;Ahmad et al, 2017). Further, the goodness-of-fit findings parallel those reported for populations with varying characteristics (García-Campayo et al, 2012;Mills et al, 2014;Bartolo et al, 2017;Hinz et al, 2017;Rutter and Brown, 2017;Doi et al, 2018;Lee and Kim, 2019).…”

The Depression Anxiety Stress Scale-21 in Chinese Hospital Workers: Reliability, Latent Structure, and Measurement Invariance Across Genders

“…If we do not evaluate measurement invariance, the comparison of means between male and female medical stuffs could be problematic. A number of studies (Wu and Huang, 2014;Doi et al, 2018) have demonstrated that other depression and anxiety measurement scales have reliable measurement invariance (e.g., Beck Depression Inventory-II, the 7-item Generalized Anxiety Disorder Scale). Some studies have examined the measurement invariance of the DASS-21 across genders (Gomez et al, 2014;Jafari et al, 2017;Lu et al, 2018).…”

Mental Health Status of the General Population during the COVID-19 Pandemic: A Cross-Sectional National Survey in Japan

“…The GAD-7 was translated into Japanese through back translation 28 with prior studies confirming the reliability and validity of the Japanese version. 28,29,30 The sensitivity and specificity of the Japanese version of the GAD-7 were 88% and 82%, respectively. 28 For each item, responses are rated on a 4-point scale from 0 to 3, with higher scores representing increased levels of anxiety (total score range 0-21).…”