Reliability and Validity of the Persian Version of the 9-Item and 2-Item Patient Health Questionnaires (PHQ-9 and PHQ-2) as Screening Tools for Diagnosing Depression among Patients with Coronary Heart Disease (CHD)

: Background: Patient Health Questionnaire-9 (PHQ-9) and Patient Health Questionnaire-2 (PHQ-2) have been characterized as appropriate screening tools for coronary heart patients. However, their psychometric properties have not been assessed in Iranian coronary heart patients. Objectives: This study aimed to determine the psychometric properties of the Persian versions of PHQ-9 and PHQ-2 in patients with Coronary Heart Disease (CHD). Methods: This cross-sectional study was conducted to investigate the psychometric properties of the Persian versions of PHQ-9 and PHQ-2 in patients with CHD. Totaly, 284 patients with CHD referred to Imam Ali Hospital in Kermanshah were selected through purposive sampling. They were first given a structured clinical interview (SCID-I) and were then asked to complete PHQ-9, PHQ-2, and Beck Depression Inventory-version 2 (BDI-II). The data were analyzed by descriptive statistics, Cronbach’s α, Spearman’s correlation coefficient, exploratory factor analysis, and Receiver Operating Characteristic (ROC) curve. Results: Cronbach’s alpha was 0.86 for PHQ-9 and 0.77 for PHQ-2. The correlation between PHQ-9, and BDI-II and PHQ-2 was 0.74 and 0.80, respectively (P < 0.001). Additionally, the correlation between PHQ-2 and BDI-II was 0.64 (P < 0.001). Using exploratory factor analysis, a one-factor structure was extracted. The optimal cutoff point for PHQ-9 was ≥ 8 with the sensitivity of 0.80, specificity of 0.81, and Area Under the Curve (AUC) of 0.87 (95% confidence interval: 0.83 - 0.91). Additionally, the optimal cutoff point for PHQ-2 was ≥ 3 with the sensitivity of 0.68, specificity of 0.83, and AUC of 0.81 (95% confidence interval: 0.75 - 0.86). Conclusion: The Persian versions of PHQ-9 and PHQ-2 possessed acceptable psychometric properties and could, consequently, be used to screen depression in CHD patients.