Accuracy of the Xpert MTB/RIF test for the diagnosis of pulmonary tuberculosis in children admitted to hospital in Cape Town, South Africa: a descriptive study

Nicol, Mark P.; Workman, Lesley; Isaacs, Washiefa; Munro, Jacinta; Black, Faye; Eley, Brian; Boehme, Catharina; Zemanay, Widaad; Zar, Heather J.

doi:10.1016/s1473-3099(11)70167-0

Cited by 299 publications

(293 citation statements)

References 17 publications

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“…Data were obtained from a study of hospitalized South African children who were suspected to have CPTB (9). Details on the design of the study are available from the original publications (9,20).…”

Section: Methodsmentioning

confidence: 99%

“…Details on the design of the study are available from the original publications (9,20). Briefly, between February 2009 and June 2014, children were consecutively enrolled when they presented to a hospital in Cape Town, South Africa, with signs or symptoms suggestive of pulmonary tuberculosis (PTB).…”

Section: Methodsmentioning

confidence: 99%

“…Briefly, between February 2009 and June 2014, children were consecutively enrolled when they presented to a hospital in Cape Town, South Africa, with signs or symptoms suggestive of pulmonary tuberculosis (PTB). Inclusion criteria were: 1) cough and at least 1 additional factor suggestive of CPTB (9,20); 2) age younger than 15 years; and 3) a parent or legal guardian who provided informed consent. Children were excluded if: 1) they had received tuberculosis treatment or prophylaxis for more than 72 hours or 2) their place of residence precluded follow-up.…”

Section: Methodsmentioning

confidence: 99%

“…In recent years, new tests for CPTB have been developed, and their accuracy has been evaluated using mycobacterial culture as a reference standard (4,9). Although culture is currently considered the best available reference standard, its sensitivity for detecting CPTB is acknowledged to be imperfect (3,4,10).…”

mentioning

confidence: 99%

“…In the present study, we re-analyzed the results of a study of hospitalized children suspected to have CPTB in which data on commonly used tests for CPTB had been prospectively collected (9). The tests include 3 microbiological tests, the tuberculin skin test (TST), and chest radiography.…”

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confidence: 99%

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Diagnostic Test Accuracy in Childhood Pulmonary Tuberculosis: A Bayesian Latent Class Analysis

Schumacher¹,

Smeden²,

Dendukuri³

et al. 2016

American Journal of Epidemiology

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Evaluation of tests for the diagnosis of childhood pulmonary tuberculosis (CPTB) is complicated by the absence of an accurate reference test. We present a Bayesian latent class analysis in which we evaluated the accuracy of 5 diagnostic tests for CPTB. We used data from a study of 749 hospitalized South African children suspected to have CPTB from 2009 to 2014. The following tests were used: mycobacterial culture, smear microscopy, Xpert MTB/RIF (Cepheid Inc.), tuberculin skin test (TST), and chest radiography. We estimated the prevalence of CPTB to be 27% (95% credible interval (CrI): 21, 35). The sensitivities of culture, Xpert, and smear microscopy were estimated to be 60% (95% CrI: 46, 76), 49% (95% CrI: 38, 62), and 22% (95% CrI: 16, 30), respectively; specificities of these tests were estimated in accordance with prior information and were close to 100%. Chest radiography was estimated to have a sensitivity of 64% (95% CrI: 55, 73) and a specificity of 78% (95% CrI: 73, 83). Sensitivity of the TST was estimated to be 75% (95% CrI: 61, 84), and it decreased substantially among children who were malnourished and infected with human immunodeficiency virus (56%). The specificity of the TST was 69% (95% CrI: 63%, 76%). Furthermore, it was estimated that 46% (95% CrI: 42, 49) of CPTB-negative cases and 93% (95% CrI: 82; 98) of CPTB-positive cases received antituberculosis treatment, which indicates substantial overtreatment and limited undertreatment. childhood pulmonary tuberculosis; diagnosis; latent class analysis; overtreatment; sensitivity; specificity Abbreviations: CPTB, childhood pulmonary tuberculosis; CrI, credible interval; HIV, human immunodeficiency virus; PTB, pulmonary tuberculosis; TST, tuberculin skin test.Tuberculosis in children is an important global health problem. There are an estimated 0.5 to 1 million new cases each year (1, 2), with childhood pulmonary tuberculosis (CPTB) being the most common form. One of the major challenges in diagnosing CPTB is the lack of sensitive diagnostic tests (3-6). In clinical practice, the diagnosis of CPTB therefore relies on a combination of imperfect tests, which gives rise to unknown degrees of under-or overtreatment (7,8).In recent years, new tests for CPTB have been developed, and their accuracy has been evaluated using mycobacterial culture as a reference standard (4, 9). Although culture is currently considered the best available reference standard, its sensitivity for detecting CPTB is acknowledged to be imperfect (3,4,10). The culture reference standard thus inevitably leads to true CPTB case patients being misclassified as being negative for CPTB. If these misclassifications by the reference standard are ignored, then the assessment of the test accuracy can be biased (11)(12)(13)(14).To address the problem of the lack of an accurate reference standard, multivariable diagnostic algorithms for CPTB have been proposed to combine information from multiple imperfect diagnostic tests (including tests for tuberculosis infection and clinical data) in a sy...

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Diagnostic Test Accuracy in Childhood Pulmonary Tuberculosis: A Bayesian Latent Class Analysis

Schumacher¹,

Smeden²,

Dendukuri³

et al. 2016

American Journal of Epidemiology

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Xpert® MTB/RIF assay for pulmonary tuberculosis and rifampicin resistance in adults

Steingart

Sohn

Schiller

et al. 2013

Cochrane Database of Systematic Reviews

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260

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Background Accurate and rapid detection of tuberculosis (TB) and drug resistance are critical for improving patient care and decreasing the spread of TB. Xpert® MTB/RIF assay (Xpert) is a rapid, automated test that can detect both TB and rifampicin resistance, within two hours after starting the test, with minimal hands-on technical time, but is more expensive than conventional sputum microscopy. Objectives To assess the diagnostic accuracy of Xpert for pulmonary TB (TB detection), both where Xpert was used as an initial test replacing microscopy, and where Xpert was used as an add-on test following a negative smear microscopy result. To assess the diagnostic accuracy of Xpert for rifampicin resistance detection where Xpert was used as the initial test, replacing conventional culture-based drug susceptibility testing. The population of interest was adults suspected of having pulmonary TB or multidrug-resistant TB (MDR-TB), with or without HIV infection. Search methods We performed a comprehensive search of the following databases: Cochrane Infectious Diseases Group Specialized Register; MEDLINE; EMBASE; ISI Web of Knowledge; MEDION; LILACS; BIOSIS; and SCOPUS. We also searched the metaRegister of Controlled Trials (mRCT) and the search portal of the WHO International Clinical Trials Registry Platform to identify ongoing trials. We performed searches on 25 September 2011 and we repeated them on 15 December 2011, without language restriction. Selection criteria We included randomized controlled trials, cross-sectional, and cohort studies that used respiratory specimens to compare Xpert with culture for detecting TB and Xpert with conventional phenotypic drug susceptibility testing for detecting rifampicin resistance. Data collection and analysis For each study, two review authors independently extracted a set of data using a standardized data extraction form. When possible, we extracted data for subgroups by smear and HIV status. We assessed the quality of studies using the QUADAS-2 tool. We carried out meta-analyses to estimate the pooled sensitivity and specificity of Xpert separately for TB detection and rifampicin resistance detection using a bivariate random-effects model. We estimated the median pooled sensitivity and specificity and their 95% credible intervals (CrI). Main results We identified 18 unique studies as eligible for this review, including two multicentre international studies, one with five and the other with six distinct study centres. The majority of studies (55.6%) were performed in low-income and middle-income countries. In 17 of the 18 studies, Xpert was performed by trained technicians in reference laboratories. When used as an initial test replacing smear microscopy (15 studies, 7517 participants), Xpert achieved a pooled sensitivity of 88% (95% CrI 83% to 92%) and pooled specificity of 98% (9...

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Xpert® MTB/RIF assay for pulmonary tuberculosis and rifampicin resistance in adults

Steingart

Schiller

Horne

et al. 2014

Cochrane Database of Systematic Reviews

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838

791

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Background Accurate, rapid detection of tuberculosis (TB) and TB drug resistance is critical for improving patient care and decreasing TB transmission. Xpert® MTB/RIF assay is an automated test that can detect both TB and rifampicin resistance, generally within two hours after starting the test, with minimal hands‐on technical time. The World Health Organization (WHO) issued initial recommendations on Xpert® MTB/RIF in early 2011. A Cochrane Review on the diagnostic accuracy of Xpert® MTB/RIF for pulmonary TB and rifampicin resistance was published January 2013. We performed this updated Cochrane Review as part of a WHO process to develop updated guidelines on the use of the test. Objectives To assess the diagnostic accuracy of Xpert® MTB/RIF for pulmonary TB (TB detection), where Xpert® MTB/RIF was used as both an initial test replacing microscopy and an add‐on test following a negative smear microscopy result. To assess the diagnostic accuracy of Xpert® MTB/RIF for rifampicin resistance detection, where Xpert® MTB/RIF was used as the initial test replacing culture‐based drug susceptibility testing (DST). The populations of interest were adults presumed to have pulmonary, rifampicin‐resistant or multidrug‐resistant TB (MDR‐TB), with or without HIV infection. The settings of interest were intermediate‐ and peripheral‐level laboratories. The latter may be associated with primary health care facilities. Search methods We searched for publications in any language up to 7 February 2013 in the following databases: Cochrane Infectious Diseases Group Specialized Register; MEDLINE; EMBASE; ISI Web of Knowledge; MEDION; LILACS; BIOSIS; and SCOPUS. We also searched the metaRegister of Controlled Trials (mRCT) and the search portal of the WHO International Clinical Trials Registry Platform to identify ongoing trials. Selection criteria We included randomized controlled trials, cross‐sectional studies, and cohort studies using respiratory specimens that allowed for extraction of data evaluating Xpert® MTB/RIF against the reference standard. We excluded gastric fluid specimens. The reference standard for TB was culture and for rifampicin resistance was phenotypic culture‐based DST. Data collection and analysis For each study, two review authors independently extracted data using a standardized form. When possible, we extracted data for subgroups by smear and HIV status. We assessed the quality of studies using QUADAS‐2 and carried out meta‐analyses to estimate pooled sensitivity and specificity of Xpert® MTB/RIF separately for TB detection and rifampicin resistance detection. For TB detection, we performed the majority of analyses using a bivariate random‐effects model and compared the sensitivity of Xpert® MTB/RIF and smear microscopy against culture as reference standard. For rifampicin resistance detection, we undertook univariate meta‐analyses for sensitivity and sp...

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Accuracy of the Xpert MTB/RIF test for the diagnosis of pulmonary tuberculosis in children admitted to hospital in Cape Town, South Africa: a descriptive study

Cited by 299 publications

References 17 publications

Diagnostic Test Accuracy in Childhood Pulmonary Tuberculosis: A Bayesian Latent Class Analysis

Diagnostic Test Accuracy in Childhood Pulmonary Tuberculosis: A Bayesian Latent Class Analysis

Xpert® MTB/RIF assay for pulmonary tuberculosis and rifampicin resistance in adults

Xpert® MTB/RIF assay for pulmonary tuberculosis and rifampicin resistance in adults

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