DISEASE BURDEN OF CHRONIC HEPATITIS B AMONG IMMIGRANTS IN CANADA

Purpose: The prevalence of chronic hepatitis B (CHB) infection among immigrants to Canada ranges from 2% to 15%, among whom 40% develop advanced liver disease.  The objective of this study was to estimate the disease burden of CHB among immigrants in Canada using Markov cohort models comparing a cohort of immigrants with CHB versus a control cohort of immigrants without CHB.

Method: We developed two Markov cohort models to estimate life years (LY), quality adjusted life years (QALY), and lifetime direct medical costs since 2006: one for a cohort of immigrants with CHB living in Canada and one age-matched control cohort of immigrants without CHB living in Canada. The differences in LY, QALY, and lifetime direct medical costs between the two cohorts were calculated to evaluate the disease burden of CHB among immigrants living in Canada.  In the model for immigrants with CHB, a total of 37 health states that include combination of serologic status (HBsAg and HBeAg), liver inflammation (alanine transaminase(ALT) (normal/elevated)), viral load (high/low) and clinical states (cirrhosis, HCC, liver transplant), were incorporated into the model in order to reflect the natural history of CHB.  Parameter values were derived from the published literature. 

Result: Our model suggested that the cohort of immigrants with CHB lost average 4.5 LY, increased average $70,177 for lifetime direct medical costs, and had a higher lifetime risk for decompensated cirrhosis (12%), hepatocellular carcinoma (16%), and liver transplant (5%) over the lifetime of the cohort when compared to the control cohort.  For a total estimate of 297,572 immigrants with CHB currently living in Canada, it could potentially lose a total of about 1.3 million LY and increase a total of 20 billion on the health care system as a direct result of CHB.

Conclusion: We show that the economic burden of CHB among immigrants living in Canada is heavy.  There was a significant loss of life years and quality adjusted life years and an increase in direct medical costs attributed to CHB among immigrants living in Canada. Governments and health systems need to develop policies which promote early recognition of CHB, and raise public awareness regarding hepatitis B in order to extend the lives of infected immigrants.