Trends in mortality after diagnosis of hepatitis B or C infection: 1992-2006

Abstract

Background & aims: Chronic hepatitis B (HBV) or C (HCV) virus infection has been associated with increased risk of death, particularly from liver- and drug-related causes. We examined specific causes of death among a population-based cohort of people infected with HBV or HCV to identify areas of excess risk and examine trends in mortality.

Methods: HBV and HCV cases notified to the New South Wales (NSW) Health Department between 1992 and 2006 were linked to cause of death data and HIV/AIDS notifications. Mortality rates and standardised mortality ratios (SMRs) were calculated using person time methodology, with NSW population rates used as a comparison.

Results: The study cohort comprised 42,480 individuals with HBV mono-infection and 82,034 with HCV mono-infection. HIV co-infection increased the overall mortality rate three to 10-fold compared to mono-infected groups. Liver-related deaths were associated with high excess risk of mortality in both HBV and HCV groups (SMR 10.0, 95% CI 9.0-11.1; 15.8, 95% CI 14.8-16.8). Drug-related deaths among the HCV group also represented an elevated excess risk (SMR 15.4, 95% CI 14.5-16.3). Rates of hepatocellular carcinoma (HCC)-related death remained steady in both groups. A decrease in non-HCC liver-related deaths was seen in the HBV group between 1997 and 2006, but not in the HCV group. After a sharp decrease between 1999 and 2002, drug-related mortality rates in the HCV group have been stable.

Conclusions: Improvements in HBV treatment and uptake have most likely reduced non-HCC liver-related mortality. Encouragingly, HCV drug-related mortality remained low compared to pre-2002 levels, likely due to changes in opiate supply, and maintenance or improvement in harm reduction strategies.