F-13 : Diagnostic Accuracy and Turnaround Time of the Xpert MTB/RIF Assay in Routine Clinical Practice = F-13 : Diagnostic Accuracy and Turnaround Time of the Xpert MTB/RIF Assay in Routine Clinical Practice

다국어 초록 (Multilingual Abstract)

The Xpert MTB/RIF assay (Xpert) was introduced for timely and accurate detection of tuberculosis (TB). The aim of this study was to determine the diagnostic accuracy and turnaround time (TAT) of Xpert in clinical practice in South Korea. We retrospectively reviewed the medical records of patients in whom Xpert using sputum were requested. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the diagnosis of pulmonary tuberculosis (PTB) and detection of rifampicin resistance were calculated. In addition, TAT of Xpert was compared with those of other tests. Total 681 patients in whom Xpert was requested were included in the analysis. The sensitivity, specificity, PPV and NPV of Xpert for diagnosis of PTB were 79.5% (124/156), 100.0% (505/505), 100.0% (124/124) and 94.0% (505/537), respectively. Those for the detection of rifampicin resistance were 57.1% (8/14), 100.0% (113/113), 100.0% (8/8) and 94.9% (113/119), respectively. The median TAT of Xpert to the report of results and results confirmed by physicians in outpatient settings were 0 (0-1) and 6 (3-7) days, respectively. Median time to treatment after initial evaluation was 7 (4-9) days in patients with Xpert, but was 21 (7-33.5) days in patients without Xpert. Xpert showed acceptable sensitivity and excellent specificity for the diagnosis of PTB and detection of rifampicin resistance in areas with intermediate TB burden. Additionally, the assay decreased time to the initiation of anti-TB drugs through shorter TAT.The Xpert MTB/RIF assay (Xpert) was introduced for timely and accurate detection of tuberculosis (TB). The aim of this study was to determine the diagnostic accuracy and turnaround time (TAT) of Xpert in clinical practice in South Korea. We retrospectively reviewed the medical records of patients in whom Xpert using sputum were requested. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the diagnosis of pulmonary tuberculosis (PTB) and detection of rifampicin resistance were calculated. In addition, TAT of Xpert was compared with those of other tests. Total 681 patients in whom Xpert was requested were included in the analysis. The sensitivity, specificity, PPV and NPV of Xpert for diagnosis of PTB were 79.5% (124/156), 100.0% (505/505), 100.0% (124/124) and 94.0% (505/537), respectively. Those for the detection of rifampicin resistance were 57.1% (8/14), 100.0% (113/113), 100.0% (8/8) and 94.9% (113/119), respectively. The median TAT of Xpert to the report of results and results confirmed by physicians in outpatient settings were 0 (0-1) and 6 (3-7) days, respectively. Median time to treatment after initial evaluation was 7 (4-9) days in patients with Xpert, but was 21 (7-33.5) days in patients without Xpert. Xpert showed acceptable sensitivity and excellent specificity for the diagnosis of PTB and detection of rifampicin resistance in areas with intermediate TB burden. Additionally, the assay decreased time to the initiation of anti-TB drugs through shorter TAT.