Impact of Molecular Drug Susceptibility Testing on the Time to Multidrug-resistant Tuberculosis Treatment Initiation

BACKGROUND: The purpose of this study was to evaluate the current status and trends in the coverage of molecular drug susceptibility testing (mDST), and the impact of mDST on the time to multidrug-resistant tuberculosis (MDR-TB) treatment initiation in Korea. METHODS: We included confirmed rifampin-resistant (RR)/MDR-TB patients who submitted application forms for novel drug uses to the National TB Expert Review Committee from September 1, 2016 to November 30, 2019. We retrospectively reviewed their medical records. RESULTS: < 0.001). Independent predictors of shorter time to MDR-TB treatment initiation were retreatment case (adjusted hazard ratio [aHR], 1.30; 95% confidence interval [CI], 1.10-1.54), Xpert testing (aHR, 2.42; 95% CI, 2.03-2.88), and LPA testing (aHR, 1.83; 95% CI, 1.55-2.16). Transfer to another healthcare facility was inversely related to shorter time to treatment initiation (aHR, 0.74; 95% CI, 0.63-0.88). CONCLUSION: mDST coverage is gradually increasing and contributes to reducing the time to MDR-TB treatment initiation. Further efforts are needed to achieve universal access to mDST and to properly integrate mDST into routine clinical practice.