Are the PHQ-9 and GAD-7 Suitable for Use in India? A Psychometric Analysis
journal contributionposted on 2021-08-02, 03:11 authored by J De Man, P Absetz, T Sathish, A Desloge, T Haregu, Brian OldenburgBrian Oldenburg, LCM Johnson, KR Thankappan, ED Williams
Background: Cross-cultural evidence on the factorial structure and invariance of the PHQ-9 and the GAD-7 is lacking for South Asia. Recommendations on the use of unit-weighted scores of these scales (the sum of items’ scores) are not well-founded. This study aims to address these contextual and methodological gaps using data from a rural Indian population. Methods: The study surveyed 1,209 participants of the Kerala Diabetes Prevention Program aged 30–60 years (n at risk of diabetes = 1,007 and n with diabetes = 202). 1,007 participants were surveyed over 2 years using the PHQ-9 and the GAD-7. Bifactor-(S – 1) modeling and multigroup confirmatory factor analysis were used. Results: Factor analysis supported the existence of a somatic and cognitive/affective subcomponent for both scales, but less explicitly for the GAD-7. Hierarchical omega values were 0.72 for the PHQ-9 and 0.76 for the GAD-7. Both scales showed full scalar invariance and full or partial residual invariance across age, gender, education, status of diabetes and over time. Effect sizes between categories measured by unit-weighted scores versus latent means followed a similar trend but were systematically higher for the latent means. For both disorders, female gender and lower education were associated with higher symptom severity scores, which corresponds with regional and global trends. Conclusions: For both scales, psychometric properties were comparable to studies in western settings. Distinct clinical profiles (somatic-cognitive) were supported for depression, and to a lesser extent for anxiety. Unit-weighted scores of the full scales should be used with caution, while scoring subscales is not recommended. The stability of these scales supports their use and allows for meaningful comparison across tested subgroups. Clinical Trial Registration: Australia and New Zealand Clinical Trials Registry: ACTRN12611000262909 http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=336603&isReview=true.
This work was supported by the National Health and Medical Research Council (NHMRC), Australia (Grant ID 1005324); the Faculty of Medicine and Health Sciences of the University of Antwerp (Grant ID 37025). The contents of this manuscript are solely the of the authors and do not reflect the views of the funders. The funders had no involvement in the study design; collection, analysis and interpretation of data; writing of the report; and the decision to submit the article for publication.
JournalFrontiers in Psychology
Article NumberARTN 676398
PublisherFRONTIERS MEDIA SA
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Social SciencesPsychology, MultidisciplinaryPsychologyPatient Health QuestionnaireIndiameasurement invariancedepressiongeneralized anxiety disorder assessmentsum score reliabilityconfirmatory bifactor modelingomega hierarchicalGENERALIZED ANXIETY DISORDERPATIENT HEALTH QUESTIONNAIRE-9MEASUREMENT INVARIANCEDEPRESSIONSUBSCORESINDEXESVERSION