TB diagnosis cheaper with triage test

Press release – 19 December 2013 – A novel triage approach results in lower costs for diagnosing tuberculosis in low- and middle-income countries
A group of Dutch, American, and British investigators show a cheaper way to diagnose tuberculosis. They report in the journal PLOS ONE that using a less expensive first triage test, followed by the more expensive, specific Xpert MTB/Rif test, can save money and increase access to tuberculosis services. With over 8 million new cases and 1.3 million deaths worldwide in 2012, tuberculosis remains a major killer disease in poor countries.

Lead investigator Anja van’t Hoog at the Amsterdam Institute for Global Health and Development, Academic Medical Center, used a cost-effectiveness model to evaluate various triage test characteristics and scenarios to diagnose tuberculosis. She said, ‘We found that if an initial triage test costs less than 5 US dollars and only those who are found positive by the test are then tested with the Xpert MTB/Rif, we can bring down the total cost for diagnosing tuberculosis patients by at least one-third. This means that more cases could be diagnosed and placed on life-saving treatment.’

After decades, new diagnostic tests are now becoming available that can better and more quickly diagnose tuberculosis than the standard techniques. New diagnostic tests must be highly sensitive, meaning that they will not miss any tuberculosis cases, but they also must be highly specific, meaning that they must not give false-positive results. These requirements drive up the cost of the test. This is multiplied by the fact that a majority of person requiring TB investigations will not have TB. Therefore, the cost for a single confirmed case is quite high. The Xpert MTB/Rif test has both high sensitivity and specificity and it is recommended for worldwide use by the World Health Organization, however it is relatively expensive to use for all patients requiring tuberculosis testing.
A triage test with high sensitivity but only moderate specificity would be a useful first step to select patients for further testing by more expensive and more specific tests such as Xpert MTB/Rif.

Investment now in the development or reconfiguration of simple, inexpensive triage tests, which can indicate that a patient may have tuberculosis and should undergo confirmatory testing, is urgently needed to save costs and prevent deaths from undiagnosed tuberculosis.

The study was funded by the US National Institute of Allergy and Infectious Diseases (Contract No. HHSN272200900050C).

Link to paper: http://dx.plos.org/10.1371/journal.pone.0082786


Media Contact:

Lead investigator: Anja van‘t Hoog
Academic Medical Center of the University of Amsterdam, Department of Global Health
Amsterdam Institute for Global Health and Development
T: + 31 20 566 1407
E: a.h.vanthoog@aighd.org




About the Tuberculosis Clinical Diagnostics Research Consortium (TB CDRC)
The CDRC is an inter-disciplinary consortium of scientists, clinicians and other trained personnel with expertise in TB diagnostics, clinical trials, and international studies, funded by the US National Institute of Allergy and Infectious Diseases (Contract No. HHSN272200900050C). The unique mission of the CDRC is to provide data early in the developmental pipeline on the performance of investigational diagnostics and their potential impact on TB management algorithms in endemic countries. The CDRC contributes to the science of diagnostics and will inform and advise scientists and manufacturers on further development and refinement of diagnostics that promise to accelerate and improve the accuracy of TB diagnosis and the rapid detection of drug resistance. www.tbcdrc.org.