GenoType MTBDR assays for the diagnosis of multidrug-resistant tuberculosis: a meta-analysis

¹ Dept of Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Quebec, Canada
² Dept of Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Quebec, Canada; and Respiratory Epidemiology & Clinical Research Unit, Montreal Chest Institute, Montreal, Quebec, Canada

^* To whom correspondence should be addressed. E-mail: madhukar.pai{at}mcgill.ca.

	Abstract

The global extensively drug-resistant tuberculosis (TB) response plan calls for implementation of rapid tests to screen patients at risk of drug-resistant TB. Currently, two line probe assays exist, the INNO-LiPA®Rif.TB assay and the GenoType® MTBDR assay. While LiPA studies have been reviewed, accuracy of GenoType assays has not been systematically reviewed.

We did a systematic review and used meta-analysis methods appropriate for diagnostic accuracy. After literature searches, we identified 14 comparisons for rifampicin and 15 comparisons for isoniazid in 10 articles that used GenoType MTBDR assays. Accuracy results were summarized in forest plots and pooled using bivariate random-effects regression.

The pooled sensitivity (98.1%; 95% CI 95.9, 99.1) and specificity (98.7%; 95% CI 97.3, 99.4) estimates for rifampicin resistance were very high and consistent, across all subgroups, assay versions and specimen types. The accuracy for isoniazid was variable, with sensitivity lower (84.3%; 95% CI 76.6, 89.8) and more inconsistent than specificity (99.5%; 95% CI 97.5, 99.9).

GenoType MDTBR assays demonstrate excellent accuracy for rifampicin resistance, even when used on clinical specimens. While specificity is excellent for isoniazid, sensitivity estimates were modest and variable. Together with data from demonstration projects, this meta-analysis provides evidence for policy making and clinical practice.