Reliability, Validity, and Measurement Invariance of the General Anxiety Disorder Scale Among Chinese Medical University Students

Abstract

Background: Medical students are affected by high levels of general anxiety disorder. However, few studies have specifically focused on the applicability of universal anxiety screening tools in this sample. This study was aimed to evaluate the psychometric property of the 7-item Generalized Anxiety Disorder Scale (GAD-7) among Chinese medical university students.Methods: A questionnaire survey was conducted among 1,021 medical postgraduates from six polyclinic hospitals. Internal consistency and convergent validity of the GAD-7 were evaluated. Factor analyses were used to test the construct validity of the scale. An item response theory (IRT) framework was used to estimate the parameters of each item. Multi-group confirmatory analyses and differential item function analyses were used to evaluate the measurement equivalence of the GAD-7 across age, gender, educational status, and residence.Results: Cronbach's α coefficient was 0.93 and the intraclass correlation coefficients ranged from 0.71 to 0.87. The GAD-7 summed score was significantly correlated with measures of depression symptoms, perceived stress, sleep disorders, and life satisfaction. Parallel analysis and confirmatory factor analysis supported the one-factor structure of the GAD-7. Seven items showed appropriate discrimination and difficulty parameters. The GAD-7 showed good measurement equivalence across demographic characteristics. The total test information of the scale was 22.85, but the test information within the range of mild symptoms was relatively low.Conclusions: The GAD-7 has good reliability, validity, and measurement invariance among Chinese medical postgraduate students, but its measurement precision for mild anxiety symptoms is insufficient.

Psychometric Properties of the Generalized Anxiety Disorder Scale-7 Item (GAD-7) in a Large Sample of Chinese Adolescents

“…The findings of the PCA in this study paralleled previous studies on the GAD-7 based on young adult samples [ 26 , 39 , 40 ]. Specifically, the results for factor loadings revealed a unidimensional structure with strong loadings (all factor loadings values > 0.6).…”

“…The Cronbach’s α coefficients of the GAD-7 in adolescents by sex and age ranged from 0.93–0.95, indicating excellent internal consistency. This research finding paralleled the early research in which the Cronbach’s alpha coefficients were at good to excellent levels in different populations [ 20 , 21 , 23 , 26 , 39 ]. In our study, Cronbach’s α was at least 0.93 regardless of groups by sex and age; thus, excellent internal reliability of the GAD-7 was verified in Chinese adolescents as well.…”

“…The GAD-7 has been translated to Chinese and validated in Chinese outpatients in a general hospital in 2010 [ 22 ]. Since then, the GAD-7 has been validated in other Chinese adult samples in hospital settings [ 15 , 23 , 24 ] and university students [ 25 , 26 ]. Given that adolescents may differently comprehend a questionnaire’s items in the same way as adults do, examining the psychometric properties of the GAD-7 in adolescents is essentially needed.…”

Factors Associated with Mental Health among International Students during the COVID-19 Pandemic in South Korea

“…The responses range from "not at all" (0) to "nearly every day" (3), and the total score for the seven items ranges from 0 to 21. In this study, the levels of anxiety were categorized as "without anxiety symptoms" (0-4), "mild" (5-9), "moderate" (10)(11)(12)(13)(14), and "severe" (15-21) [19]. Third, depression levels were measured using the Patient Health Questionnaire (PHQ-9).…”

“…The participants can choose a response that ranges from "not at all" (0) to "nearly every day" (3), and the total score for the nine items ranges from 0 to 27. The levels of depression for the study were categorized as "without depression symptoms" (0-4), "mild" (5-9), "moderate" (10)(11)(12)(13)(14), "moderately severe" (15)(16)(17)(18)(19), and "severe" (20-27) [21].…”