Table 3

Comparison of the SVM model and IGRA in diagnosing Mtb infection among HIV-positive inpatients with low CD4+ T cell count

ParameterSVMIGRA
AUC0.85 (0.76 to 0.94)0.80 (0.75 to 0.85)
Accuracy79% (67% to 87%)77% (69% to 83%)
Specificity74% (60% to 86%)100% (94% to 100%)
Sensitivity87% (66% to 97%)61% (50% to 71%)
NPV92% (79% to 98%)64% (53% to 73%)
PPV62% (44% to 79%)100% (94% to 100%)
K-S/lift score0.64/2.120.61/1.68
  • Data in parentheses represent 95% CI. The performance of SVM model compared with IGRA was measured by K-S test and lift score (p<0.001).

  • AUC, area under the ROC curve; IGRA, interferon-gamma release assay; K-S, Kolmogorov-Smirnov test; Mtb, Mycobacterium tuberculosis; NPV, negative predictive value; PPV, positive predictive value; SVM, support vector machine.