Xpert MTB/RIF Use Is Associated With Earlier Treatment Initiation and Culture Conversion Among Patients With Sputum Smear-Negative Multidrug-Resistant Tuberculosis

Abstract

Background While rapid molecular diagnostic tests for tuberculosis (TB) have decreased detection time of M. tuberculosis and drug resistance, whether their use improves clinical care and outcomes is uncertain. To address these knowledge gaps, we evaluated whether use of the Xpert MTB/RIF assay impacts treatment and clinical outcome metrics among patients treated for sputum smear-negative multidrug-resistant (MDR)-TB. Methods A retrospective cohort of adult patients initiating treatment for sputum smear-negative MDR-TB at the National Center for Tuberculosis and Lung Diseases in Tbilisi, Georgia from 2011-2016. The Xpert MTB/RIF was introduced in Georgia in 2010 and implemented into programmatic use in 2014. Exposure was availability of an Xpert result at time of diagnosis. Time to second-line treatment initiation, sputum culture conversion, and end-of-treatment outcomes were determined from. Time to event was compared using a Cox proportional hazards model. Results Among 151 patients treated for sputum smear-negative MDR-TB (96% culture positive), the Xpert was utilized in the clinical management of 78 (52%) patients and not used in 73 (48%). An adjusted analysis controlling for potential confounders found that patients in the Xpert group had shorter median time to second-line treatment (13 vs. 56 days, adjusted hazard ratio [aHR]10.21, p<0.0001) and culture conversion (61 vs. 93 days, aHR 1.93, p<0.001). There was no difference in treatment outcomes. Conclusions Use of the Xpert in the management of sputum smear-negative MDR-TB decreases time to second-line therapy and sputum culture conversion, providing evidence of its clinical impact and supporting its programmatic utility.

Diagnosis and Treatment Pathway of MDR/RR-TB in Taizhou, Zhejiang Province, China

“…In this study, we assessed the waiting time between receiving a DST and initiating treatment and the factors associated with the waiting time for a DST, treatment, pre-treatment attrition, and treatment outcomes. Considering that the clear evidence from other studies has found that efficient diagnostics tests can expedite the process of drug-resistance testing [ 23 ], the DST waiting time in our study excluded the duration between performing a DST and reporting DST results so as to avoid the impact of the detection time of DST methods, which is different from the diagnosis delay described by other published studies [ 3 , 7 ]. As a result, the median time from first seeking medical care to receiving a DST was 24 days.…”