S'abonner

Reassessment of the positive predictive value and specificity of Xpert MTB/RIF: a diagnostic accuracy study in the context of community-wide screening for tuberculosis - 17/08/16

Doi : 10.1016/S1473-3099(16)30067-6 
Jennifer Ho, DrMBBS a, c, , Phuong Thi Bich Nguyen, PhD d, Thu Anh Nguyen, PhD d, Khoa Hien Tran, MD e, Son Van Nguyen, MD e, Nhung Viet Nguyen, PhD f, Hoa Binh Nguyen, PhD f, g, Khanh Boi Luu, BPH d, Greg J Fox, MBBS a, b, Guy B Marks, MBBS a, c
a Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia 
b Central Clinical School, Sydney Medical School, University of Sydney, Sydney, NSW, Australia 
c South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia 
d Woolcock Institute of Medical Research, Hanoi, Vietnam 
e Ca Mau Centre for Social Disease Prevention, Ca Mau, Vietnam 
f National Tuberculosis Program, Hanoi, Vietnam 
g Centre for Operational Research, International Union Against Tuberculosis and Lung Disease, Paris, France 

* Correspondence to: Dr Jennifer Ho, Woolcock Institute of Medical Research, 431 Glebe Point Rd, Glebe, NSW 2037, Australia Correspondence to: Dr Jennifer Ho Woolcock Institute of Medical Research 431 Glebe Point Rd Glebe NSW 2037 Australia

Summary

Background

Community-wide screening for tuberculosis with Xpert MTB/RIF as a primary screening tool overcomes some of the limitations of conventional screening. However, concerns exist about the low positive predictive value of this test in screening settings. We did a cross-sectional assessment of this diagnostic test to directly estimate the actual positive predictive value of Xpert MTB/RIF when used in the setting of community-wide screening for tuberculosis, and to draw an inference about the specificity of the test for tuberculosis detection.

Methods

Field staff visited households in 60 randomly selected villages in Ca Mau province, Vietnam. We included people aged 15 years or older who provided written informed consent and were able to produce 0·5 mL or more of sputum, irrespective of reported symptoms. Participants were tested with Xpert MTB/RIF, then those with positive results had two further sputum samples tested for smear microscopy and culture, and underwent chest radiography at the provincial TB Health Center. The positive predictive value of Xpert MTB/RIF was compared against two reference standards for tuberculosis diagnosis—a positive sputum culture for Mycobacterium tuberculosis, and a positive sputum culture or a chest radiograph consistent with active pulmonary tuberculosis. We then calculated the specificity of Xpert MTB/RIF for tuberculosis detection on the basis of these positive predictive values and disease prevalence in this setting.

Findings

43 435 adults consented to screening with Xpert MTB/RIF. Sputum samples of 0·5 mL or greater were collected from 23 202 participants, producing 22 673 valid results. 169 participants had positive Xpert MTB/RIF results (0·39% of those screened and 0·75% of those with valid sputum results). The positive predictive value of Xpert MTB/RIF was 61·0% (95% CI 52·8–68·7) when compared against a positive sputum culture and 83·9% (76·8–89·2) when compared against a positive sputum culture or chest radiograph consistent with active tuberculosis. On the basis of these positive predictive values, the specificity of Xpert MTB/RIF was determined to be between 99·78% (95% CI 99·71–99·84) and 99·93% (99·88–99·96).

Interpretation

The positive predictive value and specificity of Xpert MTB/RIF in the context of community-wide screening for tuberculosis is substantially higher than that predicted in previous studies. Our findings support the potential role of Xpert MTB/RIF as a primary screening tool to detect prevalent cases of tuberculosis in the community.

Funding

Australian National Health and Medical Research Council.

Le texte complet de cet article est disponible en PDF.

Plan


© 2016  Elsevier Ltd. Tous droits réservés.
Ajouter à ma bibliothèque Retirer de ma bibliothèque Imprimer
Export

    Export citations

  • Fichier

  • Contenu

Vol 16 - N° 9

P. 1045-1051 - septembre 2016 Retour au numéro
Article précédent Article précédent
  • Safety, tolerability, and immunogenicity of a recombinant toxic shock syndrome toxin (rTSST)-1 variant vaccine: a randomised, double-blind, adjuvant-controlled, dose escalation first-in-man trial
  • Michael Schwameis, Bernhard Roppenser, Christa Firbas, Corina S Gruener, Nina Model, Norbert Stich, Andreas Roetzer, Nina Buchtele, Bernd Jilma, Martha M Eibl
| Article suivant Article suivant
  • Viraemia and Ebola virus secretion in survivors of Ebola virus disease in Sierra Leone: a cross-sectional cohort study
  • Edward Green, Luke Hunt, J C Gareth Ross, Nina Marie Nissen, Tanya Curran, Anjna Badhan, Katherine A Sutherland, Jade Richards, James S Lee, Samuel H Allen, Steven Laird, Mandy Blackman, Ian Collacott, Paul A Parker, Andrew Walbridge, Rebecca Phillips, Sia Jammie Sellu, Agnes Dama, Alpha Karim Sheriff, Joseph Zombo, Doris Ngegba, Alieh H Wurie, Francesco Checchi, Timothy J Brooks

Bienvenue sur EM-consulte, la référence des professionnels de santé.
L’accès au texte intégral de cet article nécessite un abonnement.

Déjà abonné à cette revue ?

Mon compte


Plateformes Elsevier Masson

Déclaration CNIL

EM-CONSULTE.COM est déclaré à la CNIL, déclaration n° 1286925.

En application de la loi nº78-17 du 6 janvier 1978 relative à l'informatique, aux fichiers et aux libertés, vous disposez des droits d'opposition (art.26 de la loi), d'accès (art.34 à 38 de la loi), et de rectification (art.36 de la loi) des données vous concernant. Ainsi, vous pouvez exiger que soient rectifiées, complétées, clarifiées, mises à jour ou effacées les informations vous concernant qui sont inexactes, incomplètes, équivoques, périmées ou dont la collecte ou l'utilisation ou la conservation est interdite.
Les informations personnelles concernant les visiteurs de notre site, y compris leur identité, sont confidentielles.
Le responsable du site s'engage sur l'honneur à respecter les conditions légales de confidentialité applicables en France et à ne pas divulguer ces informations à des tiers.


Tout le contenu de ce site: Copyright © 2025 Elsevier, ses concédants de licence et ses contributeurs. Tout les droits sont réservés, y compris ceux relatifs à l'exploration de textes et de données, a la formation en IA et aux technologies similaires. Pour tout contenu en libre accès, les conditions de licence Creative Commons s'appliquent.