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

Abstract

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. 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. 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. 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.