A systematic review of rapid drug susceptibility tests for multidrug-resistant tuberculosis using rifampin resistance as a surrogate.

Background: The emergence of multidrug-resistant tuberculosis (MDR-TB) has prompted the development of rapid drug susceptibility assays with a focus on rifampin in recent years. Systematic reviews with evaluation of predictive values for different assays are scarce.

Method: MEDLINE was searched on 6 September 2008 for English articles that contain concurrent original data for generating summary measures of sensitivity, specificity and likelihood ratios of rapid rifampin susceptibility assays.

Results/conclusions: Significant heterogeneity was found in likelihood ratios across studies of all assays except nitrate reductase assay and colorimetric assays. Although rapid assays are fairly reliable for ruling out MDR-TB, careful consideration of clinical risk factors is required before using these assays to rule in MDR-TB under different epidemiological settings.