Table 2. Sensitivity, specificity, positive and negative predictive values of Xpert MTB/RIF, using culture as gold standard.

	Culture n (%)
Xpert MTB/RIF  n (%)	Positive	Negative	Total
Positive	78 (70.3)	33 (29.7)	111
Negative	0 (0)	301 (100)	301
Total	78	334	412
	% (95% CI)
Sensitivity	100.0% (95.4–100.0)
Specificity	90.1% (86.4–93.1)
Positive predictive value	70.3% (63.1–76.6)
Negative predictive value	100.0% (96.1–100.0)

CI: Confidence Interval