‘Pooled’ TB testing could save NHS millions and speed up diagnosis, study suggests

**Lead**

A novel approach to tuberculosis (TB) diagnostics, known as ‘pooled’ testing, could offer substantial savings for the National Health Service (NHS) while simultaneously improving the speed and accuracy of diagnosis, according to a recent modelling study published in a peer-reviewed medical journal. The technique, which involves combining several patient samples into a single test batch, is already used in blood screening for diseases like HIV, but its application to TB has been limited. Researchers now argue that adopting this method for TB could be a cost-effective game-changer for public health in the UK, particularly in regions with higher rates of the disease.

**Context**

Tuberculosis remains a significant public health challenge in the United Kingdom, with over 4,000 cases reported annually. While the overall incidence is relatively low compared to the global burden, the disease disproportionately affects vulnerable populations, including the homeless, prisoners, and recent immigrants from high-prevalence countries. The standard diagnostic pathway for TB involves collecting sputum samples from patients with suspected active pulmonary TB. These samples are then sent to a laboratory for molecular testing, typically using a technique called GeneXpert, which can detect the DNA of the Mycobacterium tuberculosis bacterium and identify resistance to the key antibiotic, rifampicin.

The current process, however, is resource-intensive. Each individual sample requires its own cartridge and a dedicated run on the testing machine. In laboratories with high throughput, this can lead to bottlenecks, longer turnaround times, and increased costs. The NHS, already under immense financial pressure, spends a considerable sum on TB diagnostics each year. The new study, conducted by a team of health economists and infectious disease modellers, proposes a solution: pool samples from multiple patients into a single test. If the pooled test returns a negative result, all patients in that batch are cleared. If it returns positive, the individual samples are then retested separately to identify which patient has the infection.

The modelling, based on real-world data from NHS laboratories in London and the Midlands, suggests that this approach could reduce the number of tests performed by up to 40% in low-prevalence settings. In areas where TB is more common, the savings would be smaller but still significant. The key is the ‘pool size’—the number of samples combined. The study found that a pool of five to ten samples offers the best balance between cost savings and diagnostic accuracy.

**Analise**

Why does this matter now? The UK is currently grappling with a resurgence of TB in some urban centres, partly linked to the cost-of-living crisis and overcrowded housing. At the same time, the NHS is under a mandate to become more efficient, with the government pushing for technological innovations that can deliver ‘more for less’. Pooled testing fits this brief perfectly. It does not require new machinery or expensive reagents; it simply changes the workflow. The primary investment is in laboratory management software and staff training to handle the logistics of pooling and deconvolution.

From a patient perspective, the benefits are clear. Faster diagnosis means quicker initiation of treatment, which reduces the period of infectiousness and improves outcomes. For the health system, the savings—estimated to be in the millions of pounds annually—could be redirected to contact tracing, preventive therapy, and support for patients undergoing the lengthy six-month treatment regimen. The study also highlights a potential reduction in the environmental footprint of diagnostics, as fewer plastic cartridges and reagents would be consumed.

However, the approach is not without risks. Pooled testing can lead to a slight loss of sensitivity, meaning very early or low-bacterial-load infections might be missed. The study’s authors acknowledge this and recommend that pooled testing be used primarily for screening populations with a moderate to low pre-test probability of TB, rather than for patients with strong clinical symptoms. Furthermore, the logistics of tracking samples through the pooling and retesting process require robust digital infrastructure, which is not yet uniformly available across all NHS trusts.

**Fontes**

The information in this article is based on a modelling study published in *The Lancet Microbe* (September 2026 edition), titled “Cost-effectiveness of pooled sputum testing for tuberculosis diagnosis in the UK: a modelling study.” Additional context was drawn from public health data released by the UK Health Security Agency (UKHSA) and the National Institute for Health and Care Excellence (NICE) guidelines on TB diagnosis. No direct interviews were conducted for this report. All figures and trends described are derived from the published study and publicly available NHS statistics.