Factorial invariance and network structure of the GAD-7 in a large sample of adult Filipinos during the COVID-19 pandemic

Background: Evidence on the dimensionality and measurement invariance of the Generalized Anxiety Disorder 7-item scale (GAD-7) has remained mixed, especially in anxiety-inducing crises. Studies that examine the complex interaction of GAD symptoms during the COVID-19 pandemic have received relatively little attention in non-Western low- and middle-income countries. This study aimed to examine the GAD-7’s factor structure and test its measurement invariance across gender and age groups, and use the network approach to identify the central anxiety symptoms driving the interaction of GAD symptoms. Methods: From March to July 2020, the ultra-brief GAD-2 screened 4,564 Filipinos aged 18 to 72 (M = 26.32, SD = 6.82) who consequently completed the GAD-7 (α = 0.81). We performed confirmatory factor analysis (CFA) and multigroup CFA to evaluate the factor structure and measurement invariance of the GAD-7, respectively. We used network analysis to evaluate the accuracy and stability of the GAD network and to identify central symptoms. Results: The two-factor structure of the GAD-7 (somatic and cognitive/affective) yielded a better model fit than the one-factor structure and was invariant across gender and age groups. The network analysis identified “trouble relaxing” (somatic) and “worrying too much about different things” (cognitive/affective) as symptoms central to the network structure of GAD. Conclusions: This study supported the somatic and cognitive/affective dimensions of the GAD-7 in the Philippines and identified central symptoms that act as key levers facilitating the GAD symptom network. Future research and intervention can use the study findings to improve treatment efficacy and efficiency.