Psychometric Properties and Factor Structure of the Portuguese Version of the Patient Health Questionnaire-15 (PHQ-15)

The Patient Health Questionnaire-15 (PHQ-15) has been widely used as a screening instrument for Somatic Symptom Disorder (SSD) in different healthcare settings, as well as in scientific research. So far, there is no documentation of a validation of the Portuguese version of the PHQ-15. A sample of 215 subjects was selected for this study. The survey questionnaire included PHQ-15, SF-20, DASS-21, and sociodemographic and clinical characteristics. Principal component analysis was performed to reveal the structure of the internal consistency of the PHQ-15. The data was validated using Confirmatory Factor Analysis. PHQ-15 scores were correlated with SF-20 and DASS-21 dimension scores (r & GE;.58). Three factors (general pain and discomfort; sexual and cardiac discomfort; state of dizziness) that explained 55.6% of the total variance were identified. The PHQ-15 Portuguese version has shown good reliability (Cronbach's & alpha;=.88) and good evidence of validity for detecting patients with somatic symptoms.