Reductions in Advanced Chronic Liver Disease Among People Who Inject Drugs: The ETHOS Engage Study

BACKGROUND AND AIMS: Liver disease is a significant risk for people who inject drugs due to the high burden of hepatitis C virus (HCV). There is limited data on the impact of the direct-acting antiviral (DAA) therapy era on liver disease among people who inject drugs. This study evaluated baseline and longitudinal liver disease in a national cohort of people who inject drugs recruited over three Waves: 2018-2019, 2019-2021, and 2023-2025. METHODS: The ETHOS Engage Study is an observational cohort of people who inject drugs attending drug treatment clinics and needle and syringe programs in Australia. Participants completed a questionnaire and underwent point-of-care HCV RNA testing (Xpert HCV Viral Load Fingerstick) and liver stiffness measurement (LSM) by vibration-controlled transient hepatic elastography (FibroScan). Advanced chronic liver disease was defined by LSM of 10 kPa or above. RESULTS: Among all enrolments with a valid LSM (n = 3126, 79% recruited at drug treatment clinics), 11% had advanced chronic liver disease, decreasing from 12.0% (154/1287) in 2018-2019 to 7.9% (66/839) in 2019-2021, and 6.4% (62/967) in 2023-2025. In adjusted analyses, participants recruited between 2019-2021 and 2023-2025 were less likely to have advanced chronic liver disease (vs. 2018-2019; aOR 0.66, 95% CI: 0.48-0.90 and aOR 0.56, 95% CI: 0.40-0.77, respectively). Current HCV infection declined from 24% in 2018-2019 to 10% in 2023-2025. Among participants with LSM in more than one wave and current HCV infection at first visit and no current HCV infection at second visit (n = 44), advanced chronic liver disease declined from 19% to 5%. CONCLUSIONS: Unrestricted access to DAA therapies in Australia has been associated with reduced liver disease burden among people who inject drugs. Monitoring of liver health in this population is important, given potential ageing and non-HCV liver disease impacts.