Hospitalizations in Immigrants and Nonimmigrants Diagnosed With Chronic Hepatitis C Infection in Québec

Background:  Rates of hospitalization due to chronic hepatitis C virus (HCV) are increasing in Canada and the United States. A large proportion of immigrants originate from countries with intermediate to high HCV prevalence but are not screened for HCV post-arrival and may therefore have increased risks of liver-related complications and hospitalization.

Methods:  We conducted a retrospective cohort study of reported HCV cases in Québec, Canada, from 1998 to 2007 that were linked to administrative health databases. Outcomes included all-cause and liver-related hospitalizations and in-hospital days in immigrants compared with nonimmigrants adjusted for age, sex, and comorbidities.

Results:  We identified 20 139 HCV cases; 9% (N = 1821) were immigrants. At diagnosis, immigrants were older (47.6 vs 43.2 years) and more likely to have hepatocellular carcinoma (HCC; 0.93% vs 0.31%), while nonimmigrants were 2- to 10-fold more likely to have substance use-related comorbidities. Mean time to HCV diagnosis after arrival was 9.8 years. Nonimmigrants had higher rates of all-cause hospitalization (adjusted rate ratio [95% confidence interval], 1.42 [1.35-1.47]), driven by mental illness and injury and/or poisoning. Unadjusted liver-related hospitalization rates were similar between cohorts. After adjustment, immigrant status was associated with lower rates of liver-related hospitalization (0.68 [.53-.88]).

Conclusions:  Higher burden of all-cause hospitalization in nonimmigrants likely reflects more prevalent behavioral comorbidities. Similar liver-related hospitalization rates appear to be driven by older age in immigrants who were more likely to have HCC at diagnosis possibly reflecting delayed HCV diagnosis. These findings suggest that earlier screening and treatment in immigrants could play an important role in preventing HCV complications in this population.