Factor Structure of Persian Translation of the Patient Health Questionnaire in Iranian Earthquake Survivors

Background: There is great need across the globe for self-report scales of depression that are brief to administer, comprehensive in content, and psychometrically valid. As most of the widely used and well-validated scales originate in English, it is essential to carefully translate them, following the psychometric validation of the adapted scales. Objectives: The current study aimed at investigating the translation and validation of the Persian version of one of the most widely utilized self-report depression scales in the world, the patient health questionnaire (PHQ). Methods: The current study evaluated the validity and reliability of the PHQ in a population-based sample of 600 adult survivors of an earthquake in Iran in 2015. Researchers used the forward-backward method to translate the PHQ-9 into the Persian language. Data were analyzed using both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Results: Consistent with the results of validation studies on the original English-language versions of the scales, the current study found strong evidence of internal consistency (Cronbach’s alpha = 0.86). CFA suggested that the 1-factor structure fit reasonably well. Convergent validity was confirmed by the significant and positive correlation between the scores of national stressful events survey for posttraumatic stress disorder-short scale (NSESSS-PTSD) and the PHQ-9 (r = 0.29, P < 0.001). Approximately one-third of the sample reported some depression symptoms, with less than 10% indicating moderately severe to severe symptoms. Conclusions: Although replication studies are needed, the current study results suggested that the Persian version of the PHQ-9 was a valid and reliable tool to efficiently, comprehensively, and accurately assess depression symptoms in the Iranian subjects.