Factor structure and measurement invariance of the Patient Health Questionnaire-9 for female and male primary care patients with major depression in Germany

摘要

Background: Depression is characterized by gender specific distinctions, with women being affected more often than men. The Patient Health Questionnaire-9 (PHQ-9) is frequently used to assess depression in primary healthcare. Previous research has yielded heterogeneous findings on the factor structure, and little is known of its measurement invariance across gender. The aim of this study was 1) to evaluate the fit of four previously hypothesized models of PHQ-9 factor structure in patients with major depression in German family practices, and 2) to test the measurement invariance of the best fitting model across gender.