Utility of a depression score to predict candidacy for hepatitis C virus therapy in veterans: a prospective longitudinal study

Abstract

The frequency and determinants of receipt of antiviral therapy once a diagnosis of a mood disorder is established in hepatitis C virus (HCV)-infected patients remains unknown. To examine the incidence and determinants of receiving antiviral therapy in HCV-infected veterans with abnormal scores of Zung Self-Rating Depression Scale (SDS). We systematically evaluated the presence of psychiatric disorders among HCV-infected patients with initial referral between September 2000 and May 2002. We reviewed medical records, obtained history, and administered Zung SDS to evaluate for depressive symptoms. Patients with psychiatric disorders were referred for psychiatric evaluation. The primary outcome was the receipt of antiviral therapy during and after the initial evaluation up to December 1, 2003. The association between SDS scores and receipt of antiviral therapy was examined in a multivariate Cox proportional hazards regression. A total of 424 patients completed a Zung SDS. The scores were normal in only 43% of all patients, and were impaired mildly in 25%, moderately in 23%, and severely in 9%. Zung SDS scores were significantly higher in patients who served during the Vietnam War era, participated in combat, or had lower albumin levels. At the end of the first visit, 180 (42%) had psychiatric disorders. An abnormal Zung score (>55) was the only reason for referral to psychiatry in 83 of 180 patients; and in those 78 (94%) a formal psychiatric evaluation confirmed depressive disorder. Psychiatric disorders were the sole contraindication to therapy in 145 (34%) patients in whom eligibility for antiviral therapy was achieved in 42 (29%) during a mean follow-up duration of 27 months. Approximately one-quarter of patients with psychiatric disorders may become eligible for antiviral therapy following subsequent management of these disorders. The Zung self-screening test is an easy, valid method for detecting mood disorders in HCV-infected veterans.