A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
Cost-effectiveness analyses of tuberculosis (TB) preventive treatment rarely consider long-term TB consequences. We examined how long-term TB consequences influence the effectiveness and cost-effectiveness of TB prevention among persons who immigrate to Canada. By using a Markov microsimulation model of 400,000 persons immigrating to Canada in 2025, we compared current postarrival TB infection screening levels (0.5%) with a screening level of 68% among new immigrants. Modelling scenarios included acute TB consequences and long-term TB-related death, illness, and healthcare costs (25-year horizon, 1.5% discount rate). Including long-term TB-related consequences increased the estimated TB-related quality-adjusted life years (QALYs) lost by 2.1-fold (95% uncertainty range 1.7–2.5-fold). When long-term TB-related consequences were included, estimated QALYs gained from expanded screening increased 2.4-fold (95% uncertainty range 1.6–4.4-fold), reducing the cost per QALY from $235,088 to $100,742 CAD. Ignoring long-term TB consequences substantially underestimates the effectiveness and cost-effectiveness of preventive interventions; such consequences should be incorporated into future evaluations.
Tuberculosis (TB) is the world’s leading cause of death from a single infectious agent, killing an estimated 1.23 million persons worldwide in 2024 ( 1 ). Shifts in global migration patterns have changed the epidemiologic landscape for TB in low-incidence regions, and migrant populations bear disproportionately high TB effects ( 2 ). In migrant populations, most TB disease occurs from the progression of TB infection acquired before immigration ( 3 ). Therefore, providing TB preventive treatment (TPT) to persons who recently immigrated should be considered among other TB elimination strategies ( 4 ). However, results of cost-effectiveness analyses evaluating systematic screening and treatment for TB infection among persons who recently immigrated to low-incidence settings have been mixed ( 5 , 6 ), and the implementation of such programs is rare ( 7 ). Also, there is substantial variability in how existing studies consider the risks and consequences of TB disease and TPT ( 8 ). Nearly all studies only consider the acute consequences (disease and death) of TB during the treatment period, omitting the long-term illness and death associated with post-TB consequences ( 9 ). However, emerging research has highlighted that healthcare utilization spikes in the years after TB treatment ( 10 ), and TB survivors are at substantially higher risk for illness and death compared with those who never had TB ( 11 , 12 ).
Failure to account for the long-term consequences of TB disease might underestimate the quality-adjusted life years (QALYs) gained and cost-effectiveness of TB infection screening and TPT. A global analysis of disability-adjusted life years associated with TB suggests post-TB consequences account for half of the total TB-related health issues ( 9 ). Similarly, an analysis of a hypothetical preventive intervention in high-incidence, low-middle-income settings found considering post-TB consequences substantially reduced…