All-cause mortality and causes of death in the Swiss Hepatitis C Cohort Study

Abstract

AbstractBackground & AimsWith the introduction of direct-acting antiviral agents (DAA), mortality rates and causes of death among persons with hepatitis C virus (HCV) infection are likely to change over time. However, the emergence of such trends may be delayed by the relatively slow progression of chronic hepatitis C. To date, detailed analyses of cause-specific mortality among HCV-infected persons over time remain limited.MethodsWe evaluated changes in causes of death among the Swiss Hepatitis C Cohort Study (SCCS) participants, from 2008 to 2016. We analysed risk factors for all-cause and cause-specific mortality, accounting for changes in treatment, fibrosis stage and use of injectable drugs over time. Mortality ascertainment was completed by linking lost-to-follow-up participants to the Swiss Federal Statistical Office (SFSO) death registry.ResultsWe included 4,700 SCCS participants, of whom 478 died between 2008 and 2016. Linkage to the SFSO death registry substantially improved the information on causes of death (from 42% of deaths with unknown cause to 10% after linkage). Leading causes of death were liver failure (crude death rate 4.4/1000 person-years), liver cancer (3.4/1000 p-yrs) and non-liver cancer (2.8/1000 p-yrs), with an increasing proportion of cancer-related deaths over time. Cause-specific analysis showed that persons with sustained virologic response (SVR) were less at risk for liver-related mortality than those never treated or treated unsuccessfully.ConclusionsAlthough the expected decrease in mortality is not yet observable, causes of death among HCV-infected persons evolved over time. With the progressive widening of guidelines for DAA use, liver-related mortality is expected to decline in the future. Continued monitoring of cause-specific mortality will remain important to assess the long-term effect of DAA and to design effective interventions.Lay summaryLeading causes of death among persons with hepatitis C virus (HCV) infection in the Swiss Hepatitis C Cohort study evolved over the past years, with an increasing proportion of cancer-related deaths. The positive impact of new potent anti-HCV drugs on mortality among HCV-infected persons is not yet observable, due to both the slow progression of chronic hepatitis C and the progressive relaxation of guidelines for the use of those new drugs.