The Impact of Delayed Hepatitis C Viral Load Suppression on Patient Risk: Historical Evidence from the Veterans Administration.

Abstract

The high cost of new hepatitis C (HCV) treatments has resulted in "watchful waiting" strategies being developed to safely delay treatment, which will in turn delay viral load suppression (VLS). To document if delayed VLS adversely impacted patient risk for adverse events and death. 187,860 patients were selected from the Veterans Administration's (VA) clinical registry (CCR), a longitudinal compilation of electronic medical records (EMR) data for 1999-2010. Inclusion criteria required at least 6 months of CCR/EMR data prior to their HCV diagnosis and sufficient data post-diagnosis to calculate one or more FIB-4 scores. Primary outcome measures were time-to-death and time-to-a composite of liver-related clinical events. Cox proportional hazards models were estimated separately using three critical FIB-4 levels to define early and late viral response. Achieving an undetectable viral load before the patient's FIB-4 level exceed pre-specified critical values (1.00, 1.45 and 3.25) effectively reduced the risk of an adverse clinical events by 33-35% and death by 21-26%. However, achieving VLS after FIB-4 exceeds 3.25 significantly reduced the benefit of viral response. Delaying VLS until FIB-4 >3.25 reduces the benefits of VLS in reducing patient risk.