Researchers ask if active screening for tuberculosis among vulnerable populations is cost-effective

Early detection and prompt treatment of tuberculosis (TB) are main pillars on the way to end TB as it helps preventing further transmission. Finding those at risk of developing infection, however, requires extra efforts particularly in settings where TB incidence levels are generally low, i.e. when there are less than 10 TB cases per 100,000 population.

This is where active screening targeting populations at higher risk of TB infection, which include people in urban aeras with lower incomes, people experiencing homelessness, communities in remote or isolated areas, indigenous populations, migrants, refugees, internally displaced persons and other vulnerable or marginalised groups with limited access to healthcare, could help detecting (latent) infections.

In the Eurosurveillance issue marking World TB Day 2024, Gogichadze et al. present the findings of their systematic review on active pulmonary TB screening programmes run between 2008 and 2023 in so-called high-risk groups living in low TB incidence countries. The authors wanted to identify if active searches for pulmonary TB would be cost-effective given that passive case finding approach may not be sufficient in the effort of detecting and treating TB patients.  

Active case finding 

In their search, the authors found 6,318 articles based on their search criteria and included nine of them in their review with the specific angle of active case finding that e.g. included chest X-ray, tuberculin skin test, interferon-gamma release assay and a symptoms questionnaire for screening.

Analysing the results of the reviewed articles, Gogichadze et al. conclude that “screening immigrants from countries with a TB incidence with more than 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”.

Harmonisation of methods

A comparison between levels of cost-effectiveness was, however, not possible due to the data heterogenicity and, according to the authors, requires further harmonisation of the methods for cost-effectiveness analysis.

They summarise that “based on the findings spanning 16 years and the guidelines available, we have listed several recommendations for optimising study design for active screening programmes for TB in low-incidence countries.

”Firstly, to guide policymakers, cost-effectiveness analysis should always be part of TB screening activities targeting high-risk groups in low TB incidence countries. Additionally, cost-effectiveness studies should follow national economic evaluation guidelines in case they are available and consider the published WHO guidance. Moreover, the cost-effectiveness analysis should encompass not only the expenses related to screening, but also those related to diagnosis and treatment.”