Table 1. Diagnostic accuracy of the tuberculosis culture (TB-CX) test, Xpert MTB/RIF test compared to the Lӧwenstein Jensen (LJ) culture method.

Assay				Sensitivity	Specificity	PPV	NPV	Kappa	Test Efficiency	P-value
	Solid LJ culture
TB-CX Test	Positive	Negative	Total
Positive	73	1	74
Negative	5	58	64	94%	98%	99%	92%	0.91	0.96	< 0.001
Total	78	59	137
GeneXpert
Positive	75	12	87
Negative	3	47	50	96%	80%	87%	98%	0.80	0.89	< 0.001
Total	78	59	137

Note: PPV = positive predictive value, NPV = negative predictive value, LJ = Lӧwenstein-Jensen, the kappa (k) value is a measure of test reliability, interpreted as follows: <0.4 = poor; 0.4–0.75 = fair to good; >0.75 = strong.