Adaptation of the two-item generalized anxiety disorder scale (GAD-2) to Chinese rural population: A validation study and meta-analysis

Abstract

Objective: The two-item generalized anxiety disorder scale (GAD-2) has been investigated in different populations, but with limited evaluation in the Chinese population. This study aimed to validate the diagnostic accuracy of GAD-2 for identifying GAD through a validation study along with an updated meta-analysis.

Methods: We recruited 694 adults in 2015 from "the Henan Rural Cohort study" where the GAD-7 questionnaire was adopted as the gold standard diagnosis. Receiver operating characteristics (ROC) curve and Cronbach's α were determined. Furthermore, a meta-analysis was conducted to evaluate the effectiveness of the GAD-2.

Results: In this study, 37 patients [5.33%; 95% confidence interval (CI): 3.78-7.27%] met the criteria for current GAD. The GAD-2 showed a Cronbach's alpha of 0.806 and an area under the ROC curve (AUC) of 0.954 (95% CI: 0.936-0.968). At a cutoff of 3, GAD-2 had highest Youden's index of 0.845, with a sensitivity of 0.865 and a specificity of 0.980. A total of 13 studies were included in the meta-analysis. The pooled sensitivity, specificity and diagnostic odds ratio (DOR) were 0.80, 0.82 and 17.81, respectively, at the optimal cutoff of 3.

Conclusion: GAD-2 has acceptable properties for identifying GAD at a cutoff of 3 in the Chinese rural population.

Keywords: Chinese rural population; GAD-2; Generalized anxiety disorder; Meta-analysis.