Cost-effectiveness of rapid susceptibility testing against second line drugs for tuberculosis

Post Date: 
2014-06-15
Publication: 
International Journal of Tuberculosis and Lung Disease
Summary: 


Background: Drug susceptibility testing (DST) against second-line tuberculosis drugs (SLDs) is essential for improving outcomes among multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) cases.


Objective: To evaluate the potential cost-effectiveness of rapid DST for SLDs.


Design: We constructed a decision analysis model of Xpert MTB/RIF-based TB diagnosis in East and South-East Asia to compare culture-based DST vs. a hypothetical rapid SLD DST system for specimens resistant to rifampin. Our primary outcomes were the effectiveness and incremental cost-effectiveness of a rapid SLD DST assay relative to culture-based DST.


Results: For rapid SLD DST to be more effective than culture-based DST, treating individuals with pre-XDR/XDR-TB with a standardized MDR-TB regimen while awaiting culture-based DST must incur at least 30% excess XDR-TB mortality (100% = treatment with first-line drugs); rapid SLD DST should attain an aggregate sensitivity and specificity for all pre-XDR/XDR mutations of 88% and 96%, respectively. The unit cost of the rapid SLD DST assay must approach that of culture to achieve common thresholds for cost-effectiveness in low-income countries.


Conclusion: Rapid SLD DST has the potential to be cost-effective, but must meet stringent criteria for accuracy and costs, and requires that standardized second-line treatment for pre-XDR/XDR-TB incur substantial excess mortality before the return of culture results.

Citation: 
Dowdy D, van’t Hoog A, Shah M, Cobelens F. Cost-effectiveness of rapid susceptibility testing against second line drugs for tuberculosis. Int J Tuberc Lung Dis. 2014 Jun;18(6):647-54. doi: 10.5588/ijtld.13.0776. PMID: 24903933.
Collaborators: 
  • Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
  • Department of Global Health and Amsterdam Institute for Global Health and Development, Academic Medical Centre, Amsterdam, The Netherlands