2. Opportunistic Treatment of Hepatitis C Virus Infection: A pragmatic stepped-wedge cluster randomized trial of immediate versus outpatient treatment initiation among hospitalized people who inject drugs (OPPORTUNI-C)

Aim: Hospitalizations may represent opportunities to engage people who inject drugs (PWID) in HCV-care. We present the protocol and preliminary results from an ongoing trial of immediate versus outpatient HCV-treatment initiation among hospitalized PWID (ClinicalTrials.gov, NCT04220645).

Design: Pragmatic stepped-wedge cluster-randomized trial. Intervention: Non-invasive liver disease assessment and prompt pan-genotypic DAA treatment with individualized follow-up. Standard of care: Referral to outpatient care at discharge. Methods: A pragmatic clinical trial approach is used to mimic usual clinical practice as closely as possible and enhance external validity. The stepped-wedge design involves a sequential rollout of the intervention, in which seven participating clusters will be randomized from standard of care to intervention in a stepwise manner. Data is collected from electronic patient files.The trial will include approximately 220 HCV-RNA positive individuals recruited from departments of internal medicine, addiction medicine, and psychiatry at three hospitals in Oslo. Primary outcome: Treatment completion, defined as dispensing of the final prescribed DAA-package from the pharmacy within 6 months after inclusion. Secondary outcomes: Treatment uptake, virologic response, reinfection incidence, and resistanceassociated substitutions.

Results: The first study participant was included on October 1st 2019, and inclusion was completed on December 31st 2021. A total of 218 participants were included, 108 under control conditions and 110 under intervention conditions. Preliminary results will be presented.

Conclusions: Representing a novel model of care suited to reach and engage PWID in HCV-care, this study will inform HCV elimination efforts locally and internationally. If the model proves efficacious and feasible, it should be considered for broader implementation.