Psychometric Properties and Factorial Structure of the Patient Health Questionnaire (PHQ-4) in Ecuadorian University Students

Introduction: The Patient Health Questionnaire is a brief instrument for assessing anxiety and depression, whose factorial structure is not clear. Objective: To analyze the reliability, convergent, divergent and construct validity, as well as the factorial structure, of the Patient Health Questionnaire in Ecuadorian university students. Methods: The sample consisted of 1732 students, with an average age of twenty years. 55 % were women from three universities in Loja. The instruments applied were the Acceptance and Action Questionnaire, the Psychological Capital Questionnaire, the Depression and Anxiety Scale, and the Perceived Stress Scale. Results: The factorial structure was better adjusted to the bifactorial model (CMIN/DF=14.247; CFI = 0.996; GFI = 0.996; NFI = 0.996, RMSEA = 0.087). This model is invariant between men and women. Reliability was optimal for the total scale (α=0.879; ω=0.880) and its two factors: anxiety (α=0.838; ω=0.838) and depression (α=0.779; ω=0.780). Scores were correlated with mental health indicators. Conclusions: The Patient Health Questionnaire is a scale with optimal psychometric properties for Ecuadorian university students, presenting a bifactorial structure.