Rapid and Simultaneous Tuberculosis and Antibiotic Susceptibility Testing for the Diagnosis of Pulmonary Tuberculosis and Rifampicin Resistance: A Review of Diagnostic Accuracy

Key Message

A total of six systematic reviews were identified. Three systematic reviews reported on the diagnostic accuracy of Xpert with respect to smear microscopy status. There was variability in the estimates of sensitivities and specificities in both the smear positive and smear negative subgroups in the individual studies included in these three systematic reviews, One systematic review reported that the sensitivity with Xpert was 36% to 44% higher than the sensitivity with smear microscopy. Five systematic reviews reported on the diagnostic accuracy of Xpert and/or Xpert Ultra compared with mycobacterial culture test. The sensitivities of Xpert ranged between 62% and 85%; and the specificities ranged between 98% and 99% (based on four systematic reviews). The sensitivities of Xpert Ultra ranged between 64% and 100%; and specificities ranged between 96% and 100% (based on two systematic reviews). Six systematic reviews reported on the diagnostic accuracy of Xpert or both Xpert and Xpert Ultra for the detection of rifampicin resistance compared to culture-based drug susceptibility testing. For rifampicin resistance detection with Xpert, the sensitivities ranged between 83% and 100%, and the specificities ranged between 97% and 100% (based on six systematic reviews). For rifampicin resistance detection with Xpert Ultra the sensitivities ranged between 93% and 95%, and the specificities ranged between 98% and 99% (based on two systematic reviews. The findings need to be interpreted in the light of limitations (such as variations in specimen types and settings; limited evidence for Xpert Ultra; and lack of generalizability with respect to the Canadian setting).