3. HCV treatment uptake among marginalized people who inject drugs in Norway: A registry-based study, and the Progress towards elimination of hepatitis C among people who inject drugs in Norway

Aim: improving HCV-treatment uptake among people who inject drugs (PWID) is crucial to achieve the WHO elimination targets. Aim: To assess HCV-treatment uptake and associated factors and estimate HCV-RNA prevalence in a large cohort of PWID.

Design: Registry-based study where users of the City of Oslo’s low-threshold social and health services for PWID between 2010-2016 were linked to HCV-notifications and prescriptions of HCV-treatment, opioid agonist treatment (OAT) and benzodiazepines. Cases were weighted to account for spontaneous HCV-clearance. HCV-treatment rates were calculated, and factors associated with treatment uptake were analysed using logistic regression analysis. HCV-RNA prevalence was estimated among participants in 2019

Results: Among 2436 participants with chronic HCV-infection (mean age 46.8 years, 30.7% female, 73.3% OAT), 1118 (45.9%) received HCV treatment between 2010-2019. Treatment rates increased from 1.4/100 PY (95% CI 1.1-1.8) in the pre-DAA period (2010-2013) to 3.5/100 PY (95% CI 3.0-4.0) in the early DAA-period (2014-2016) and 18.4/100 PY (95% CI 17.2-19.7) in the late-DAA period (2017- 2019), and exceeded a previously modelled elimination threshold of 50/1000 PWID in 2018 and 2019. Treatment uptake was less likely among women (aOR 0.74; 95% CI 0.62-0.89) and those aged 40-49 years (aOR 0.74; 95% CI 0.56-0.97), and more likely among participants with current OAT (aOR 1.21; 95% CI 1.01-1.45). Estimated HCV-RNA prevalence in 2019 was 23.6% (95% CI 22.3-24.9) among participants alive by the end of 2019.

Conclusions: HCV-treatment uptake among PWID increased in the DAA era. Strategies to enhance treatment among women and individuals not engaged in OAT should be addressed.