BackgroundThe level of adherence to hepatitis C virus (HCV) treatment is associated with response. High adherence throughout the initial 12 weeks is related to better virological outcomes. Several factors can influence adherence.PurposeTo assess HCV treatment adherence and to evaluate the relationship between adherence and rapid (RVR), early (EVR) and sustained virological response (SVR).Material and methodsRetrospective observational study of HCV-infected patients receiving pegylated interferon (peg-IFN) + ribavirin (RBV) ± protease inhibitor (PI) from January 2011–December 2013. Demographic and clinical data recorded: age, sex, weight, HIV infection, HCV genotype; quantitative HCV RNA; peg-IFN, RBV and PI doses, frequency and quantities dispensed; psychiatric disorders.Results183 patients (31.1% women); 14.2% HIV co-infected; 71.2% genotype 1. IL28B CT/TT genotype rate: 33/46.79.8% were treated with peg-INF + RBV and 20.2% with peg-INF + RBV + PI. 11.7% received reduced RBV/peg-IFN doses. 3.3% required growth factor.RVR: 97.4% (mean reduction: 1.91 log IU/ml). EVR: 46.1%. SVR: 57.3% (genotype 1: 47.1% vs. others: 73.8%; p = 0.011). SVR among PI treated patients: 72.7%.Overall adherence according to quantities dispensed and the Morisky-Green test were 97.35% (95.8% with >80% adherence) and 99.56% (100% > 85% adherence), respectively. Mean adherence according to quantities dispensed at 4 and 12 weeks was 100% and 99.8%, respectively.Sex, HIV co-infection or psychiatric diseases were not associated with lower adherence.No relationship was found between RVR and adherence but the EVR was found to be significantly greater with adherence levels >85% (11.1% vs. 48.3%). Adherence ≥80% was associated with (not significantly) higher rates of SVR (57.7% vs. 50%).ConclusionAdherence >80% is associated with higher cure rates and adherence >85% at 12 weeks is related to greater EVR. No relationship was found between HCV-RNA decrease at 4 weeks and adherence. Neither psychiatric disorders nor HIV co-infection influenced adherence.References and/or AcknowledgementsMathes T, Antoine SL, Pieper D. BMC Infectious Diseases 2014;14:203–16Lo Re V, Amorosa VK, Localio A, et al. Adherence to hepatitis C virus therapy in HIV/hepatitis C-Coinfected patients. CID 2009;48:186–93No conflict of interest.