Assessment of the PHQ-9 as a screening tool for depression in patients with chronic hepatitis C

Background and Objectives We examined the test characteristics of the PHQ-9, a new screening tool that has been validated in the general population but not amongst patients with hepatitis C virus (HCV). Methods The PHQ-9, CES-D and BDI-II questionnaires were administered to 129 consecutive patients with chronic HCV attending a specialty clinic between August 2005 and April 2006. Results Approximately 52% of participants reported symptoms suggesting depression. Prevalence of depression was 62% using the BDI-II, 75% per the PHQ-9 and 72% per the CES-D. We observed a strong correlation between the BDI-II, CES-D and PHQ-9 in patients on and off interferon. Scores on the three questionnaires were only moderately associated with symptoms reported by the patients. There was moderate agreement between the CES-D and BDI-II and slight agreement between both these questionnaires and the PHQ-9. Scores on the PHQ-9 correlated strongly with scores on the CES-D and BDI-II and moderately with patients' symptoms.