Table 8.

Summary of the Performance of HER2 Classification

	Discovery (n = 55)		Validation (n = 272)
	ΔΔCT cutoff-point	Clustering	ΔΔCT cutoff-point	Clustering
Sensitivity	0.76 (0.50−0.93)	0.53 (0.28−0.77)	0.82 (0.57−0.96)	0.71 (0.44−0.90)
Specificity	0.97 (0.86−1.00)	1.00 (0.91−1.00)	0.98 (0.96−0.99)	1.00 (0.99−1.00)
PPV	0.93 (0.66−1.00)	1.00 (0.63−1.00)	0.78 (0.52−0.94)	1.00 (0.48−1.00)
NPV	0.90 (0.77−0.97)	0.81 (0.67−0.91)	0.99 (0.97−1.00)	0.96 (0.92−0.98)
Accuracy	0.91 (0.80−0.97)	0.84 (0.71−0.92)	0.97 (0.95−0.99)	0.96 (0.92−0.98)
Kappa	0.776 (0.592−0.961)	0.551 (0.312−0.791)	0.786 (0.633−0.940)	0.439 (0.182−0.696)