Hepatitis C treatment uptake among people who inject drugs in Oslo, Norway: A registry-based study

Improving HCV treatment uptake among people who inject drugs (PWID) is crucial to achieving the WHO elimination targets. The aims were to evaluate HCV treatment uptake and HCV RNA prevalence in a large cohort of PWID in Norway.

Registry-based observational study where all users of the City of Oslo's low-threshold social and health services for PWID between 2010-2016 (n = 5330) were linked to HCV notifications (1990-2019) and dispensions of HCV treatment, opioid agonist treatment (OAT) and benzodiazepines (2004-2019). Cases were weighted to account for spontaneous HCV clearance. Treatment rates were calculated using person-time of observation, and factors associated with treatment uptake were analysed using logistic regression. HCV RNA prevalence was estimated among individuals alive by the end of 2019.

Among 2436 participants with chronic HCV infection (mean age 46.8 years, 30.7% female, 73.3% OAT), 1118 (45.9%) had received HCV treatment between 2010-2019 (88.7% DAA-based). 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; fibrosis restrictions) and 18.4/100 PY (95% CI 17.2-19.7) in the late DAA period (2017-2019; no restrictions). Treatment rates for 2018 and 2019 exceeded a previously modelled elimination threshold of 50/1000 PWID. 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). The estimated HCV RNA prevalence by the end of 2019 was 23.6% (95% CI 22.3-24.9).

Although HCV treatment uptake among PWID increased, strategies to improve treatment among women and individuals not engaged in OAT should be addressed.