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Table 4 Values of diagnostic accuracy with CRS as standard

From: Evaluation of the performance of an in-house duplex PCR assay targeting the IS6110 and rpoB genes for tuberculosis diagnosis in Cameroon

  Diagnostic Methods
Parameters Direct microscopy Concentrated microscopy LJ Culture
n = 123a
rpoB IS6110 D-PCR
No. of samples positive 47 49 51 57 61 62
No. of samples negative 82 80 72 72 68 67
Measures of diagnostic accuracy
 Sensitivity (%) 75.8 79.0 83.6 87.1 91.9 93.5
 Specificity (%) 100 100 100 94.0 94.0 94.0
 PPV 1 1 1 0.93 0.93 0.94
 NPV 0.82 0.84 0.86 0.89 0.93 0.94
 LR+ 14.5 15.3 15.6
 LR- 0.242 0.21 0.16 0.14 0.02 0.005
  1. PPV (positive predictive value); NPV (negative predictive value); LR+ (positive likelihood ratio); LR- (negative likelihood ratio). a excluding contaminated cultures