Active screening for tuberculosis in high-incidence Inuit communities in Canada: a cost-effectiveness analysis

Opportunities for tuberculosis elimination in the Canadian Arctic: cost-effectiveness of community-wide screening in a remote Arctic community

Background

In response to a tuberculosis (TB) outbreak in the remote community of Qikiqtarjuaq Nunavut, Canada, community leaders and the territorial government initiated community-wide screening (CWS) for tuberculosis, an expensive undertaking given the high cost of providing medical services in the Canadian arctic. Our study aim was to assess the cost-effectiveness of the Qikiqtarjuaq CWS.

Methods

We developed a hybrid decision analysis and Markov model to replicate the experience and extrapolate CWS outcomes over a 20-year time horizon. Following a hypothetical cohort with patient characteristics reflecting the demographic and testing data available from the CWS, the model compared a one-time CWS intervention with the reference case of 'no community-wide screening'.

Findings

CWS resulted in improved health gains through prevention of active tuberculosis cases compared with no CWS. It also resulted in increased costs (measured in Canadian dollars), with a very low estimated incremental cost-effectiveness ratio (ICER) of $25.10 (95% URs: cost savings-$15,874) per additional quality adjusted life year (QALY) gained compared with current standard of care approach (no CWS). Community-wide screening in this context would be considered highly cost-effective in this setting. In probabilistic sensitivity analysis, we found >99% of iterations were cost-effective at a willingness to pay threshold of $50,000/QALY gained.

Interpretation

While costly, coordinated and intensive community-wide tuberculosis screening activities are highly cost-effective in remote arctic communities when utilized in an outbreak context.

Funding

Government of Nunavut.

Cost-effectiveness of diagnostic tools and strategies for the screening and diagnosis of tuberculosis disease and infection: a scoping review

The objective of this scoping review is to understand the cost-effectiveness of current and future tools/strategies for screening and diagnosis of tuberculosis (TB) infection and disease. To this end, PubMed, EMBASE and SCOPUS were used to identify any English language reports on the cost-effectiveness of TB infection/disease screening/diagnostic strategies published between 1 January 2017 and 7 October 2023. Studies included high-burden/risk TB populations, compared diagnostic/screening methods and conducted a cost-effectiveness/economic evaluation. We stratified the included articles in four groups (cost-effectiveness of diagnosing TB disease/infection and cost-effectiveness of screening for TB disease/infection). A full-text review was conducted, and relevant costing data extracted. Of the 2417 articles identified in the initial search, 112 duplicates were removed, and 2305 articles were screened for title and abstract. 23 full articles were reviewed, and 17 fulfilled all inclusion criteria. While sputum smear microscopy (SSM) has been the primary method of diagnosing TB disease in high-burden countries, the current body of literature suggests that SSM is likely to be the least cost-effective tool for the diagnosis of TB disease. Further scale-up with molecular diagnostics, such as GeneXpert and Truenat, was shown to be broadly cost-effective, with a multitest approach likely to be cost-effective for both screening and diagnosis. There is an urgent need to increase access and remove barriers to implementation of diagnostics that have been repeatedly shown to be cost-effective, as well as to develop new diagnostic and screening technologies/strategies to address current barriers to scale-up.

Cost-effectiveness of active tuberculosis screening among high-risk populations in low tuberculosis incidence countries: a systematic review, 2008 to 2023

BackgroundIn countries with a low TB incidence (≤ 10 cases/100,000 population), active pulmonary tuberculosis (PTB) mostly affects vulnerable populations with limited access to healthcare. Thus, passive case-finding systems may not be successful in detecting and treating cases and preventing further transmission. Active and cost-effective search strategies can overcome this problem.AimWe aimed to review the evidence on the cost-effectiveness (C-E) of active PTB screening programmes among high-risk populations in low TB incidence countries.MethodsWe performed a systematic literature search covering 2008-2023 on PubMed, Embase, Center for Reviews and Dissemination, including Database of Abstracts of Reviews of Effects (DARE), National Health Services Economic Evaluation Database (NHS EED), Global Index Medicus and Cochrane Central Register of Controlled Trials (CENTRAL).ResultsWe retrieved 6,318 articles and included nine in this review. All included studies had an active case-finding approach and used chest X-ray, tuberculin skin test, interferon-gamma release assay and a symptoms questionnaire for screening. The results indicate that screening immigrants from countries with a TB incidence > 40 cases per 100,000 population and other vulnerable populations as individuals from isolated communities, people experiencing homelessness, those accessing drug treatment services and contacts, is cost-effective in low-incidence countries.ConclusionIn low-incidence countries, targeting high-risk groups is C-E. However, due to the data heterogenicity, we were unable to compare C-E. Harmonisation of the methods for C-E analysis is needed and would facilitate comparisons. To outline comprehensive screening and its subsequent C-E analysis, researchers should consider multiple factors influencing screening methods and outcomes.