Cost effectiveness analysis of introducing rapid, alternative methods to identify multidrug resistant tuberculosis in middle income countries

Background: Resistance to commonly used anti-tuberculosis (TB) drugs is emerging worldwide. Conventional drug susceptibility tests (DST) are slow and demanding. Alternative, rapid DST methods would permit the early detection of drug resistance and in turn arrest TB transmission. Methods: A cost-effectiveness analysis of five DST methods was performed in the context of a clinical trial comparing rapid and conventional DST methods. The methods under investigation were: direct phage replication assay (FASTPlaque-Response TB); direct amplification and reverse hybridization of the rpoB gene (INNO-LiPA Rif TB); indirect colorimetric MIC (MTT), and direct proportion method on Löwenstein-Jensen (DLJ). These were compared with the widely used, indirect proportion method on Löwenstein-Jensen (IDLJ). Results: All alternative DST methods were found to be cost-effective compared to other health interventions. DST methods also generate substantial costs savings in high MDR- TB prevalence settings. Excluding benefits of transmission, DLJ was the most cost-effective alternative DST method for patient groups with a MDR-TB prevalence of 2%, 5%, 20% and 50% ($94, $36, $8 and $2 per DALY respectively). Conclusion: Alternative, rapid methods for DST are cost-effective and should be considered for use by National Tuberculosis Programs in middle income countries settings.