A statistical method was used for the meta-analysis of tests for latent TB in the absence of a gold standard, combining random-effect and latent-class methods to estimate test accuracy

Sadatsafavi, Mohsen; Shahidi, Neal; Marra, Fawziah; FitzGerald, Mark J.; Elwood, Kevin R.; Guo, Na; Marra, Carlo A.

doi:10.1016/j.jclinepi.2009.04.008

« Previous Next »Journal of Clinical Epidemiology
Volume 63, Issue 3 , Pages 257-269, March 2010

A statistical method was used for the meta-analysis of tests for latent TB in the absence of a gold standard, combining random-effect and latent-class methods to estimate test accuracy

Mohsen Sadatsafavi
- Faculty of Pharmaceutical Sciences, Collaboration for Outcomes Research and Evaluation, University of British Columbia, Vancouver, British Columbia, Canada
Neal Shahidi
- Faculty of Pharmaceutical Sciences, Center for Clinical Epidemiology and Evaluation, Vancouver Coastal Health institute, Vancouver, British Columbia, Canada
Fawziah Marra
- Faculty of Pharmaceutical Sciences, Collaboration for Outcomes Research and Evaluation, Pharmacy and Vaccine Services, British Columbia Center for Disease Control, Vancouver, British Columbia, Canada
Mark J. FitzGerald
- Faculty of Medicine, Center for Clinical Epidemiology and Evaluation, Vancouver Coastal Health institute, University of British Columbia, Vancouver, British Columbia, Canada
Kevin R. Elwood
- Division of Tuberculosis Control, British Columbia Center for Disease Control, Vancouver, British Columbia, Canada
- Division of Respiratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
Na Guo
- Faculty of Pharmaceutical Sciences, Collaboration for Outcomes Research and Evaluation, University of British Columbia, Vancouver, British Columbia, Canada
Carlo A. Marra
- Faculty of Pharmaceutical Sciences, Collaboration for Outcomes Research and Evaluation, University of British Columbia, Vancouver, British Columbia, Canada
- Corresponding author. Faculty of Pharmaceutical Sciences, Collaboration for Outcomes Research and Evaluation, University of British Columbia, 2146 East Mall, Vancouver, BC V6T 1Z3, Canada. Tel.: +1-604-806-8817; fax: +1-604-875-5179.

Accepted 20 April 2009. published online 19 August 2009.

Abstract

Objective

Because of the lack of a gold standard, the diagnostic performance of tests for the detection of latent tuberculosis infection (LTBI) is not known. However, statistical methods can be used to estimate the accuracy from the studies reporting the concordance among the tests.

Study Design and Setting

We developed a random-effect latent-class model to estimate performance characteristics of three LTBI diagnostic tests: tuberculin skin test (TST, at 10-mm cutoff), QuantiFERON-TB gold (QFG), and TSPOT-TB from the studies evaluating agreement among the tests.

Results

Nineteen studies were included. QFG had a sensitivity of 0.642 (95% confidence interval [CI]: 0.593–0.691) and specificity of 0.996 (95% CI: 0.989–1.000), TSPOT-TB had a sensitivity of 0.500 (95% CI: 0.334–0.666) and specificity of 0.906 (95% CI: 0.882–0.929), and TST had a sensitivity of 0.709 (95% CI: 0.658–0.761) and specificity of 0.683 (95% CI: 0.522–0.844). Results were not sensitive to the inclusion of any single study. When only the three studies that reported on TSPOT were removed, estimates for the other two tests varied minimally.

Conclusions

Statistical methods can help estimate the accuracy of LTBI tests. Although the specificities were close to their reported values in the literature, the estimates for sensitivities were low; a finding that should be carefully evaluated.

Keywords: Tuberculosis, Meta-analysis, Sensitivity and specificity, Reproducibility of results, Statistical models, Predictive value of tests