We thank Drs Aghemo and Lampertico for their commentary on our work.[1, 2] We agree that the investigation provides evidence to support the notion that medical contraindications to interferon (IFN) and ribavirin are not the major obstacles to low rates of hepatitis C virus (HCV) treatment initiation when using IFN-based therapies. However, we disagree with the hypothesis that ‘introduction of IFN-free regimens will only increase the number of anti-HCV treatment eligible patients by 10–15%’ for a few reasons.
First, our sample was derived from the general US population, which historically has had a much lower rate of HCV infection in comparison with that found among specific groups, such as veterans and persons who inject drugs. Indeed, HCV infection was only identified in 0.5% of patients in our data set, a percentage well below the US national average of 2%. Secondly, rates of medical comorbidities that are contraindications to IFN-based therapy, such as mental health issues, have been shown to be much higher in these population subgroups. Thirdly, a variety of other reasons at the patient, provider and institutional levels have historically played a larger role as reasons for aversion to initiate IFN-based therapy than have medical contraindications.
Some of these items, for example, patients’ fear of side effects attributable to IFN or former drug users’ concerns that medication administered by injection may foster relapse to injection drug use, factors that were not evaluated as part of our data set, will be significantly diminished if not entirely eliminated by removal of IFN from HCV therapeutic regimen. Others, such as expanded screening and HCV educational programmes, should improve with a multicomponent approach as outlined by Drs Aghemo and Lampertico.