The review findings suggest that Xpert MTB/XDR provides accurate results for detection of isoniazid and fluoroquinolone resistance and can assist with selection of an optimal treatment regimen. Given that Xpert MTB/XDR targets a limited number of resistance variants in specific genes, the test may perform differently in different settings. Findings in this review should, therefore, be interpreted with caution. Xpert MTB/XDR sensitivity for ethionamide resistance detection was based only on detection of mutations in the inhA promoter region by Xpert MTB/XDR, a known limitation. High risk of bias limits our confidence in Xpert MTB/XDR accuracy for pulmonary tuberculosis.
The impact of Xpert MTB/XDR is expected to be affected by the test’s ability to detect tuberculosis (required for drug susceptibility testing (DST)), prevalence of resistance to a given drug, health care infrastructure, and access to other tests.