Trends in mortality after diagnosis of hepatitis C virus infection: an international comparison and implications for monitoring the population impact of treatment

Background & aims: People living with hepatitis C virus (HCV) are at increased risk of all-cause and liver-related mortality, although successful treatment has been shown to reduce this risk. The aim of this study was to provide baseline data on trends in cause-specific mortality and to establish an international surveillance system for evaluating the population level impact of HCV treatments.

Methods: Population level HCV diagnosis databases from Scotland (1997-2010), Australia (New South Wales [NSW]) (1997-2006), and Canada (British Columbia [BC]) (1997-2003) were linked to corresponding death registries using record linkage. For each region, age-adjusted cause-specific mortality rates were calculated, and trends in annual age-adjusted liver-related mortality were plotted.

Results: Of 105,138 individuals diagnosed with HCV (21,810 in Scotland, 58,484 in NSW, and 24,844 in BC), there were 7275 deaths (2572 in Scotland, 2655 in NSW, and 2048 in BC). Liver-related deaths accounted for 26% of deaths in Scotland, 21% in NSW, and 22% in BC. Temporal trends in age-adjusted liver related mortality were stable in Scotland (males p=0.4; females p=0.2) and NSW (males p=0.9; females p=0.9), while there was an increase in BC (males p=0.002; females p=0.04).

Conclusions: The risk of liver-related mortality after a diagnosis of HCV has remained stable or increased over time across three regions with well-established diagnosis databases, highlighting that HCV treatment programmes to-date have had minimal impact on population level HCV-related liver disease. With more effective therapies on the horizon, and greater uptake of treatment anticipated, the potential of future therapeutic strategies to reduce HCV-related mortality is considerable.