What is killing people with hepatitis C virus infection? Analysis of a population-based cohort in Canada

Abstract

BackgroundPersons with hepatitis C virus (HCV) infection are at risk of mortality from both chronic liver disease and HCV acquisition risk activities. We compared causes of death among HCV positive and negative individuals to characterize contributions of acquisition risks and viral sequelae. MethodsThe British Columbia (BC) Hepatitis Testers Cohort (BC-HTC) includes all individuals tested for HCV or reported as a HCV case since 1992, linked to health administrative data. ICD-10 codes were used to classify deaths as: 1) liver-related (LR); 2) HCV acquisition risk-related (AR); and 3) other causes. Mortality proportions and trends were assessed among HCV positive and negative individuals overall and by birth cohort (born <1945, 1945–64 and ≥1965). ResultsAs of December 31, 2018, of 1,300,204 HCV-tested individuals, 20,049 (27.5%) HCV positive and 132,999 (10.2%) HCV negative individuals had died (median age at death: 56.4 vs. 74.5 years, respectively). HCV positive individuals were more likely than negatives to die from both AR (24.7%/4.2%) and LR (23.4%/6.2%) causes. Deaths among older HCV positive individuals were more likely to be LR while younger individuals were more likely AR: 1) birth cohort <1945 (25.3%/2.7%); 2) 1945–64 (26.5%/23.7%) and ≥1965 (7.7%/59.9%). Among HCV positives, LR mortality increased from 1992 to 2014, then declined sharply, coinciding with the introduction and uptake of direct-acting antiviral drugs. AR mortality increased from 1992 to 2000, declined slowly until 2013, then rapidly increased, coinciding with the recent surge in opioid overdose deaths. ConclusionsCurative HCV treatments reduce LR mortality, but typically will not impact AR mortality. This will need to be addressed if the World Health Organization 2030 HCV mortality reduction goals are to be achieved.