UBC Theses and Dissertations
Validity and reliability of the Patient Health Questionnaire-9 for university students Zhang, Wen Qian
Depression is ranked as one of the most burdensome health conditions and is more prevalent in university students compared to the general population. Effective screening measures are an important aspect of detection and progress monitoring, as well as being key in depression research. However, current widely used measures, such as the Beck Depression Inventory-II (BDI-II) and the Center of Epidemiological Studies Depression Scale (CES-D), can be lengthy. For research participants who have to complete a battery of questionnaires and especially for depressed clients who are low on energy, it can be daunting to complete lengthy measures. Additionally, the BDI-II can be costly for research, counselling centers, and university clinics. Therefore, there is a need for a short, effective depression screen for both clinical and research purposes. The Patient Health Questionnaire-9 (PHQ-9) is an ideal candidate. It is only nine items, freely accessible, well established, and reflects the current diagnostic criteria. While there is an abundance of validity evidence for the PHQ-9 in primary and secondary care, there is a gap in validity evidence related to its use in the university population. To date, validity evidence for the inferences made from the PHQ-9 in the university population is limited to China, Japan and Nigeria, as well as a single secondary analysis in the U.S. The present study assessed internal structure, internal consistency reliability, and convergent and discriminant evidence to support the inferences made from the English version of the PHQ-9 as a depression screen for university students in Canada. A total of 204 university students completed an online survey. Results supported a unidimensional structure and high internal consistency of the PHQ-9 scores. The PHQ-9 also demonstrated the expected pattern of convergent and discriminant validity coefficients with scores on depression, anxiety, mental health functioning, and physical health functioning measures. Based on the psychometric results from this study, the PHQ-9 is tentatively recommended for use with university students.
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