Skip to main content

Diagnostic accuracy of the Xpert® MTB/RIF assay for extra-pulmonary tuberculosis: a meta-analysis

Buy Article:

$34.78 + tax (Refund Policy)

BACKGROUND: Xpert® MTB/RIF is a commercially available nucleic acid amplification test developed for the diagnosis of pulmonary tuberculosis (PTB).

OBJECTIVE: To determine the diagnostic accuracy of Xpert for the detection of extra-pulmonary tuberculosis (EPTB).

METHODS: We searched MEDLINE, EMBASE and Global Health databases from January 2010 to 15 August 2014 for studies of diagnostic performance in which Xpert was examined against culture for patients with clinically suspected EPTB. Bivariate random effects models were used to provide pooled estimates of diagnostic accuracy.

RESULTS: Thirty-six studies were identified, with a pooled sensitivity and specificity of respectively 77% (95%CI 66–85) and 97% (95%CI 94–98). Substantial variations existed between study estimates of sensitivity (I 2 = 99%) and specificity (I 2 = 96%). Among site-specific estimates for lymph, pleural fluid, cerebrospinal fluid, gastro-intestinal and urinary samples, the pooled sensitivity was lower in pleural fluid (37%, 95%CI 26–50, meta-regression P < 0.001) and higher in lymph node samples (87%, 95%CI 75–95, meta-regression P = 0.03).

CONCLUSION: Xpert has high specificity but limited sensitivity for the detection of EPTB. Although positive Xpert test results may be useful in rapidly identifying EPTB cases, negative test results provide less certainty for ruling out disease.

Keywords: Xpert MTB/RIF; extra-pulmonary tuberculosis; sensitivity; specificity; systematic review, meta-analysis

Document Type: Research Article

Affiliations: 1: *Department of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan 2: Department of Community Health Sciences, University of Calgary, Calgary 3: Departments of Surgery and Community Health Sciences, Intensive Care Unit Administration, Foothills Medical Centre, Calgary 4: §Peter Lougheed Hospital, University of Calgary, Calgary 5: Royal Alexandra Hospital, Edmonton, Alberta 6: #Department of Clinical Epidemiology, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario 7: **Departments of Medicine and Community Health Sciences, University of Calgary and the Foothills Medical Centre, Calgary, Alberta, Canada

Publication date: 01 March 2015

More about this publication?
  • The International Journal of Tuberculosis and Lung Disease (IJTLD) is for clinical research and epidemiological studies on lung health, including articles on TB, TB-HIV and respiratory diseases such as COVID-19, asthma, COPD, child lung health and the hazards of tobacco and air pollution. Individuals and institutes can subscribe to the IJTLD online or in print – simply email us at [email protected] for details.

    The IJTLD is dedicated to understanding lung disease and to the dissemination of knowledge leading to better lung health. To allow us to share scientific research as rapidly as possible, the IJTLD is fast-tracking the publication of certain articles as preprints prior to their publication. Read fast-track articles.

  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • International Journal of Tuberculosis and Lung Disease
  • Public Health Action
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content