On the path towards universal coverage of hepatitis C treatment among people receiving opioid agonist therapy (OAT) in Norway: a prospective cohort study from 2013 to 2017

Abstract

Background The development of new direct-acting antiviral (DAA) medications together with opioid agonist therapy (OAT) have been put forward as having an important role in the management and elimination of chronic hepatitis C (HCV) infection. Yet, HCV treatment uptake and coverage have remained low among OAT populations. We aimed to calculate cumulative HCV treatment coverage among individuals enrolled in OAT in Norway between 2013 and 2017, and to document the treatment transition to interferon-free regimens. Moreover, we aimed to describe adherence to DAAs in the same cohort. Methods This observational study was based on data from The Norwegian Prescription Database (NorPD). We studied dispensed OAT and HCV treatment annually to calculate the cumulative frequency, and employed secondary sources to further calculate prevalence, incidence and HCV treatment coverage from 2013 to 2017, among the OAT population. Factors associated with adherence to DAAs were identified a priori and subject to logistic regression. Results 10,371 individuals were identified with dispensed OAT, 1,475 individuals of these with dispensed HCV treatment. Annual HCV treatment coverage increased from 3.5% (95% CI: 3.2-4.4) in 2013 to 17% (95% CI: 17-20) in 2017, giving a cumulative HCV coverage among OAT patients in Norway of 38.5%. A complete shift to interferon-free treatment regimens occured, where DAAs accounting for 32% of HCV treatments in 2013 and 99% in 2017. About two-thirds of OAT patients were considered adherent to their DAA regimens across all genotypes. High-level of OAT continuity was associated with improved adherence to DAAs (aOR 1.4, 95% CI: 1-2, p=0.035). Conclusions A large increase in HCV treatment coverage attributed by a complete shift to interferon-free regimens among the Norwegian OAT population has been demonstrated. However, a further substantial scale-up in HCV treatment is required to reach the universal targets of controlling and eradicating the HCV endemic.

Centrally acting stimulants in patients receiving opioid agonist therapy; a national prospective cohort study in Norway from 2015 to 2017

“…Patients who received at least one dispensation of one or more of these drugs were included. Dispensations of DAA were also evaluated due to the frequent use of illicit stimulant drugs in the OAT population and the fact that annual dispensations of DAA against hepatitis C infection have increased the last years significantly [32,35]. The dispensed OAT opioids were stratified according to the predefined categories.…”