Depressive and anxiety disorders in chronic hepatitis C patients: Reliability and validity of the Patient Health Questionnaire

Depression and anxiety in patients with hepatitis C virus (HCV) infection influence their health-related quality of life and their adherence to antiviral treatment. Objective: To study the psychometric properties of the Patient Health Questionnaire (PHQ) as a screening instrument for depression and anxiety in HCV patients. Methods: Criterion validity, using the structured clinical interview for DSM-IV-Axis I (SCID-I) to diagnose depression and anxiety disorders as diagnostic standard, was evaluated for both summed and algorithm-based PHQ in 500 HCV patients. Correlations with quality of life (Short-Form-36 Health Survey; SF-36) and severity of illness (Hospital Anxiety and Depression Scale; HADS) were calculated to assess construct validity. Test-retest reliability and patients' reaction to the PHQ were assessed in 120 HCV patients. Results: Twenty-three percent of patients (N = 114) had a psychiatric disorder (any depressive disorder = 18.2%; major depressive disorder = 6.4%; generalized anxiety disorder = 7.0% and panic disorder = 5.8%). The questionnaire demonstrated good test-retest reliability for any depressive disorder (k = .847), major depressive disorder (k = .784), generalized anxiety disorder (k = .787), panic disorder (k = .848), and for any psychiatric disorder (k = .847). There was good agreement between PHQ and SCID-I diagnoses (for any PHQ disorder. k = .821; overall accuracy = 90.43%. sensitivity = 83.84%; specificity = 97.01%). Patients with any PHQ disorder had higher impairment on the SF-36 (p<.001). HADS depression and anxiety scores showed high correlations with PHQ depression (p<.001) and anxiety (p<.001) scores respectively. PHQ administration was well accepted by 97% of patients. Conclusions: The Spanish version of the PHQ is a reliable, valid, and useful screening instrument to detect depression, generalized anxiety and panic disorders in HCV patients. (C) 2012 Elsevier B.V. All rights reserved.