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Published on: August 17, 2018
Validation of the PHQ-4 in the general population of Quebec, Canada
Jacques D Marleau1, Mélissa Généreux2
1Direction de santé publique, Centre régional de santé et de services sociaux de la Baie-James, 312, 3(e) Rue, Chibougamau, G8P 1N5, QC, Canada.
Objective:
To evaluate the factor structure of the 4-item Patient Health Questionnaire (PHQ-4), which aims to screen for two dimensions: anxiety and depression.
Method:
Data from three surveys conducted in Quebec in 2021 among adult respondents were used to test whether a two-factor structure fits better than a one-factor model. Confirmatory factor analyses will be used to determine the best-fitting model.
Results:
Confirmatory factor analyses revealed that the two-factor structure is more appropriate than the one-factor model. Measurement invariance of the two-factor model was observed across several indicators (gender, language, place of birth, housing status, etc.), except for age. Convergent and divergent validity were also established. These findings were consistent across all three surveys.
Conclusion:
Given the strong psychometric properties of the two-factor model, its use is recommended among the adult population in Quebec. The consistency of the results further supports its validity and applicability.
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Data Validation
Key parameters for method validation include:

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