Hospital stays for hepatitis B or C virus infection or primary liver cancer among immigrants: a census-linked population-based cohort study

The recent increase in the incidence of primary liver cancer in Canada has been attributed to a higher proportion of immigrants from countries endemic for hepatitis B virus (HBV) and hepatitis C virus (HCV). We examined hospital discharges for liver disease in Canada, focusing on those for all liver-related diseases, HBV infection, HCV infection and primary liver cancer, by 3 immigration-related variables: immigration status, duration of residence in Canada and risk level of the source country.

We calculated annualized crude and age-standardized rates of a hospital stay in Canada for HBV infection, HCV infection, primary liver cancer and all liver-related diseases using data from the 2006 Canadian census (long form) linked to the Canadian Institute for Health Information Discharge Abstract Database for fiscal years 2006/07 to 2008/09. We estimated the odds of a hospital stay using logistic regression for the 3 immigration-related variables, adjusting for sociodemographic indicators.

Immigrants were less likely than Canadian-born residents to be discharged with a diagnosis of any liver-related condition (odds ratio [OR] 0.83, 95% confidence interval [CI] 0.78-0.89); however, they were more likely to be discharged with a diagnosis of HBV infection (OR 2.02, 95% CI 1.57-2.60) and primary liver cancer (OR 1.43, 95% CI 1.22-1.68). There was a clear association between a hospital stay for HBV infection and immigration from HBV-endemic countries (OR 5.15, 95% CI 3.87-6.84) and between a stay for HCV infection and immigration from HCV-endemic countries (OR 2.98, 95% CI 1.74-5.11). Adjustment for low income status and urban residence did not change the results.

Although the odds of a liver-related hospital stay were lower among immigrants than among those born in Canada, immigrants from countries at high risk for HBV infection, HCV infection and primary liver cancer were more likely than Canadian-born residents to have a corresponding liver-related hospital stay. These findings emphasize the importance of identifying immigrants with hepatitis and engaging them in care to prevent complications.