Validation of the combined Patient Health Questionnaire Anxiety and Depression Scale among people with HIV in Vietnam

Abstract

Background Our study aims to examine the factor structure, validity, and reliability of the combined scale Patient Health Questionnaire Anxiety and Depression Scale (PHQ-ADS) among people with HIV (PWH) in Vietnam. Methods Baseline data from an alcohol-reduction intervention trial among ART clients in Thai Nguyen, Vietnam were used for this analysis ( n = 1547). A score ≥10 on the PHQ-9, GAD-7 and PHQ-ADS scale was considered having clinically meaningful depression, anxiety and distress symptoms. Factor structure of the combined PHQ-ADS scale was validated using confirmatory factor analysis, and three models were tested: a one-factor, a two-factor, and a bi-factor model. Reliability and construct validity were examined. Results The prevalence of clinically meaningful depression and anxiety symptoms was 7% and 2%, respectively, while 19% had distress symptoms. A bi-factor model had the best fit to the data (RMSEA = 0.048; CFI = 0.99; TLI = 0.98). The Omega index of the bi-factor model was 0.97. The scale showed good construct validity through negative associations between depression, anxiety, distress symptoms and quality of life. Conclusions Our study supports the use of a combined scale to measure general distress for PWH, which has good validity, reliability and is unidimensional enough to justify the use of a composite depression and anxiety score.