Reliability, validity, and factorial structure of the World Health Organization-5 Well-Being Index (WHO-5) in Iranian psychiatric outpatients

Introduction: The association between psychological well-being and physical and mental health has been shown in the literature. Psychological well-being is a multifaceted concept. The World Health Organization-5 Well-Being Index (WHO-5) is a 5-item instrument used to screen for depression. However, the validity of the WHO-5 has not been investigated in Iranian psychiatric or psychological settings. Objective: To investigate the validation of the Farsi version of the WHO-5 in a sample of Iranian psychiatric outpatients. Methods: A cross-sectional study was conducted with a convenience sample of 116 Iranian volunteer psychiatric outpatients selected from the psychiatric and psychological clinics at the School of Behavioral Sciences and Mental Health - Tehran Institute of Psychiatry, Iran University of Medical Sciences. Patients completed the WHO-5, the Patient Health Questionnaire-9 (PHQ-9), the Patient Health Questionnaire-15 (PHQ-15), and the short form of the Beck Depression Inventory-13 (BDI-13). Results: The mean score of the WHO-5 was 8.95 (standard deviation [SD] = 5.49). Cronbach's α for the WHO-5 was 0.91. The WHO-5 negatively correlated with PHQ-9 (-0.358), PHQ-15 (-0.328), and BDI-13 (-0.475), indicating good validity. Factor analysis of the WHO-5 items identified one factor labeled psychological well-being. Conclusions: The WHO-5 has a single dimensional structure and acceptable psychometric parameters. The results of this study suggest that WHO-5 can be used in a clinical context in Iran.