COST EFFECTIVENESS OF SCREENING IMMIGRANTS IN CANADA FOR HEPATITIS B

Purpose: The prevalence of chronic hepatitis B (CHB) infection among immigrants to Canada ranges from 2% to 15%. Approximately 40% of those with CHB develop advanced liver disease which puts them at risk of dying of the complications of cirrhosis if left untreated. Thus, both the health and economic burden of CHB in Canada is considerable. Currently, serological screening for CHB is not routinely conducted in immigrants. The objective of this study is to build a model that projects the health and economic effects of various screening strategies for CHB conducted in immigrants to Canada.

Method: We developed a Markov simulation model of CHB to evaluate the economic and clinical consequences of screening immigrants for hepatitis B virus (HBV). Health states that include serology (HBsAg, HBeAg), inflammation (ALT), viral load and clinical states (cirrhosis, HCC, etc.), were included in the model. The Canadian health care costs applied in the simulation model were collected from the literature. We used quality-adjusted life years (QALYs) to estimate health gains associated with screening. Health state utilities from a study of 433 CHB patients attending tertiary care clinics in downtown Toronto were used. Probabilistic sensitivity analysis was conducted.

Result: Our analysis suggests that a selective hepatitis B screening program specifically for immigrants in Canada is probably cost-effective. Screen and treat prevents 73 HBV-related deaths per 10,000 persons offered screening. Screen and treat increases life expectancy by 0.04 years for all immigrants and 0.80 years for immigrants with CHB. Screen and treat associated with an increase in health (0.044 QALYs) and cost ($2380), and it has an incremental cost-effectiveness ratio of $54,400/QALY compared with no screening for all immigrants.

Conclusion: A screening program can identify those asymptomatic chronically infected individuals and offer medical treatment when appropriate according to published guidelines before advanced liver disease is present, thus extending the lives of immigrants in Canada.