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Updated: Mar 9, 2026

Diagnosing Pulmonary Tuberculosis with the Xpert MTB/RIF Test
Published on: April 9, 2012
The clinical utility of Xpert® MTB/RIF testing in induced sputum
1Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Hospital, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore.
Abstract:
We performed a prospective clinical audit in hospitalised patients with suspected pulmonary tuberculosis (PTB) with the objective of evaluating the accuracy and clinical utility of Xpert® MTB/RIF in induced sputum in an intermediate-burden setting. Of 450 patients audited, 61 (13.6%) were diagnosed with PTB based on positive culture. The sensitivity, specificity and positive and negative predictive values for Xpert in smear-negative cases for induced sputum were respectively 75%, 99.5%, 94.7% and 97.0%. Xpert in induced sputum may facilitate diagnostic yield and expedite treatment in up to a quarter of PTB patients.
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