Validity and reliability of the Generalized Anxiety Disorder-7 (GAD-7) among university students of Bangladesh.

Tahia Anan Dhira,Abdur Razzaque Sarker,Marco Innamorati,Mahir A Rahman,Jeenat Mehareen

doi:10.1371/journal.pone.0261590

Abstract

This study investigated the reliability and factorial validity of General Anxiety Disorder-7 (GAD-7) in the context of university students in Bangladesh. The research aimed to assess whether the original one-dimensional model or a model containing both somatic and cognitive-emotional factors is appropriate. A repeated cross-sectional survey design based on convenience sampling was used to collect data from 677 university students. The factor structure of the GAD-7 was assessed by exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), and its convergent validity was determined by investigating its correlations with Patient Health Questionnaire-9 (PHQ-9) and Patient Health Questionnaire Anxiety-Depression Scale (PHQ-ADS). Results showed excellent reliability of GAD-7 as measured by Cronbach’s α. CFA suggested that a modified one-factor model is appropriate for the sample. This model provided high values of comparative fit index (CFI), goodness of fit index (GFI), and Tucker Lewis Index (TLI), low value of standardized root mean square residual (SRMR) and a non-significant root mean square error of approximation (RMSEA). Correlation between GAD-7 and PHQ-9 was 0.751 and 0.934 between GAD-7 and PHQ-ADS. Overall, the study provided support for modified unidimensional structure for GAD-7 and showed high internal consistency along with good convergent validity.

Highlights

Generalized Anxiety Disorder (GAD) belongs to a group of mental health conditions collectively known as anxiety disorders, which includes panic disorder, phobias, social anxiety disorder, Obsessive-Compulsive Disorder (OCD) and Post-Traumatic Stress Disorder (PTSD) [1]
Our study examined the psychometric properties of the General Anxiety Disorder-7 (GAD-7) with a sample of university students in Bangladesh, using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA)
Other clinical and non-clinical studies conducted in Korea, Portugal, United States, Iran, Germany and, Peru have found excellent Cronbach’s α coefficient [30, 40, 41, 46, 47, 66] which show good internal consistency of GAD-7 scale across different populations

Summary

Introduction

Generalized Anxiety Disorder (GAD) belongs to a group of mental health conditions collectively known as anxiety disorders, which includes panic disorder, phobias, social anxiety disorder, Obsessive-Compulsive Disorder (OCD) and Post-Traumatic Stress Disorder (PTSD) [1]. The definition of GAD emerged from the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) where it was characterized as a residual diagnosis and only attributed to patients who did not meet diagnostic criteria for any other anxiety disorders [3,4,5]. Validity and reliability of the GAD-7 several substantial revisions, GAD was characterized as an independent anxiety disorder with diagnostic description. In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), GAD has been stated to include both psychological symptoms such as persistent worrying and overthinking, difficulty handling uncertainty, restlessness, indecisiveness, etc. Findings from general population surveys of approximately 150000 adults in 26 countries indicated that DSM-5 GAD had a combined lifetime prevalence of 3.7%, 12-month prevalence of 1.8%, and 30-day prevalence of 0.8% [8]

Methods

Results

Conclusion