Table 8.

Measures of accuracy of CNB techniques

Measures of accuracy	Palpation-guided CNB		Ultrasound-guided CNB
	%	N	%	N
Sensitivity	92.9	14	100	15
Specificity	100	23	100	31
P = 0.483
PPV	100	13	100	15
NPV	95.7	23	100	31
P = 0.463
FPR	0	13	0	15
FNR	4.2	24	0	31
P = 0.463
LR	40.9		58.1

FPR = false positive rate, FNR = false negative rate, LR = likelihood ratio, NPV = negative predictive value, PPV = positive predictive value