. 2017 Aug 7;6(8):78. doi: 10.3390/jcm6080078

Table 1.

Xpert Sensitivity and Specificity Results.

Sputum Volume	Sensitivity	Specificity *	PPV	NPV
Standard Volume Xpert ^† (n = 172)	12.5% (1/8)	99.4% (163/164)	50.0% (1/2)	95.9% (163/170)
Standard Volume Xpert ^† (n = 172)	[2.2%, 47.1%]	[96.6%, 99.9%]	[9.5%, 90.5%]	[91.7%, 98.0%]
Large Volume Xpert ^‡ (n = 164)	50.0% (4/8)	99.4% (155/156)	80.0% (4/5)	97.5% (156/159)
Large Volume Xpert ^‡ (n = 164)	[21.5%, 78.5%]	[96.5%, 99.9%]	[37.6%, 96.4%]	[93.7%, 99.0%]

Data summarized as % (n/n) [95% CIs]; PPV = Positive Predictive Value; NPV = Negative Predictive Value. * If limited to the 155 participants with both standard volume and large volume Xpert results, specificity was the same for standard volume and large volume Xpert: 99.4% (154/155) [96.4%, 99.9%]; ^† Four participants were excluded due to one Xpert failure using standard volume sputum and contamination of all cultures for three participants; ^‡ Twelve participants were excluded due to six Xpert failures using large volume sputa, three site errors leading to no large volume Xpert results, and contamination of all cultures for three participants.