The generalized anxiety disorder-7 (GAD-7) and its individual- and contextual-level correlates in Chinese adults

Anxiety disorders contribute substantially to the global mental health burden, yet evidence integrating psychometric validation of screening tools with individual- and contextual-level correlates of anxiety in large Chinese populations remains limited. This study examined the psychometric properties of the Generalized Anxiety Disorder 7-item scale (GAD-7) and explored individual- and contextual-level correlates of anxiety. A nationwide online survey was conducted among 7,730 adults in China. Anxiety symptoms were assessed using the GAD-7. Reliability was evaluated using Cronbach’s alpha and McDonald’s omega. Factorial validity and measurement invariance across gender, age group, occupation, and geographic region were examined using confirmatory factor analysis. Anxiety outcomes included continuous GAD-7 scores, ordinal anxiety severity, and binary GAD-7 screening status (GAD-7 ≥5 vs. <5). Multiple linear, ordinal logistic, and binary logistic regression models were used to examine associations between anxiety outcomes and individual- and contextual-level factors. The mean GAD-7 score was 6.66 ± 4.78, and 8.0% of participants reported severe anxiety. The GAD-7 demonstrated excellent internal consistency (α = 0.91; ω = 0.91) and a robust one-factor structure, with full measurement invariance across the examined sociodemographic groups. Female gender, younger and middle adulthood (21–50 years), selected occupational groups, and higher PHQ-9 scores were consistently associated with higher anxiety across models. Regional differences were limited. Among the contextual indicators, higher employment rates were associated with higher anxiety levels, whereas higher GDP per capita and population density were associated with lower anxiety across some outcomes. The findings provide further evidence supporting the reliability, validity, and measurement invariance of the GAD-7 in a large online sample of Chinese adults. Anxiety outcomes were more consistently associated with individual-level characteristics than with the provincial-level contextual indicators examined.