Adherence to combination therapy: influence on sustained virologic response and economic impact.

The health care burden of hepatitis C virus (HCV) infection is projected to continue to increase over the next two decades, so improving the efficacy of anti-HCV therapy has the potential to significantly affect health care utilization associated with the disease. Adherence to standard combination therapy and maintaining the doses of interferon (IFN) or peginterferon (PEG-IFN) and ribavirin (RBV) are now recognized as critical to maximizing a sustained virologic response (SVR) rate, particularly in patients infected with genotype 1 and patients who demonstrate an early virologic response. Early identification and management of the treatment-related side effects that are most likely to result in dose reductions or discontinuation might also play a role in successful adherence to therapy and achieving an SVR, as side effects are the primary reason for nonadherance. Educating patients, their family members, and their caregivers about the expectations of treatment, side effects, and the importance of maintaining doses and completing therapy is essential to optimizing adherence. Although patient quality of life (QOL) may decrease during treatment, patients achieving an SVR experience an improved QOL. Cohort economic modeling studies and available data from recent controlled trials suggest that PEG-IFN/RBV therapy increases life expectancy and is cost effective compared with standard IFN/RBV, and that the use of treatment management algorithms based on early virologic testing can substantially reduce antiviral drug costs and further improve the cost effectiveness of therapy, as can increased adherence to PEG-IFN/RBV therapy. Further research will be needed to develop optimum and cost-effective treatment strategies for the general HCV-infected population, particularly patients with comorbidities.