TABLE 1

Sensitivity and specificity of Xpert MTB/RIF assay (n = 23) in comparison with MGIT culture (n = 43d) on the pleural fluid samples (n = 162)

Xpert MTB/RIF assay resultSensitivitySpecificityPPVa, % (95% CI)NPVb, % (95% CI)LRc positiveLR negativeP
No. positive/no. tested% (95% CI)No. negative/no. tested% (95% CI)
Overall23/42d54.8 (38.8–70.1)119/119100 (96.8–100)100 (85.2–100)86.2 (79.3–91.5)0.45 (0.32–0.63)<0.01
Smear positive, culture positive4/4d100 (51.0–100)157/157100 (97.7–100)100 (39.7–100)100 (97.1–100)0.00
Smear negative, culture positive19/3850.0 (54.8–65.1)124/124100 (96.9–100)100 (83.2–100)86.2 (79.5–91.0)0.50 (0.36–69)<0.01
  • a PPV, positive predictive value.

  • b NPV, negative predictive value.

  • c LR, likelihood ratio.

  • d One culture grew M. avium and was excluded from the study.