A model for hepatitis B mortality and the effects of HBV-related outcomes on life expectancy in Iran

Studies have shown that chronic hepatitis B infection could lead to an increased risk of poor outcomes like hepatocllular carcinoma and cirrhosis. This study aimed to estimate relative risk of mortality of chronic hepatitis B infection to no infected population and their life expectancy in Iran.

Analysis is based on comparing prevalence of hepatitis B infection in general population and annual death. Prevalence of HBs Ag in all dead men and women was estimated as a weighted average of prevalence of HBs Ag in 3 liver related death (Cirrhosis, HCC and acute viral hepatic failure) and non-hepatic death by relative frequency of them. According to total death and death due to HCC and cirrhosis, relative risk of mortality was estimated. Then with age specific mortality rate of general population, life table for community and HBV infected subjects with and without 0.5 percent annual chance of seroclearance of HBs Ag were calculated and loss of life expectancy due to HBV related death was estimated.

There was a paucity of evidence based epidemiologic data from Iran in these regards. In spite of this fact the relative risk of mortality due to HBV infection associated death was estimated to be 1.3 in males and 1.4 in females. By probabilistic sensitivity analysis of used parameters in acceptable range of values, the standard deviation of RR mortality was about 0.03. This excess mortality decreased 3 years of life expectancy at one-year-old to 1 year at age 80 in both sexes.

Based on existing data and modeling, we estimated that chronic hepatitis B infection results in significantly increase mortality and decrease in life expectancy. This study should be validated by long-term prospective epidemiologic studies.