Table 4.

Detailed sensitivity and specificity report for EGFR mutation predicted probability cut-points of 0.2 and 0.6

	Development group		Validation group
	0.2	0.6	0.2	0.6
Sensitivity	68.27%	21.69%	63.33%	23.33%
Specificity	78.21%	95.25%	79.20%	96.49%
Positive predictive value	45.70%	55.10%	40.71%	60.00%
Negative predictive value	90.17%	81.91%	90.54%	84.80%
Informedness index a	0.46	0.17	0.43	0.2

^a Informedness index is calculated as sensitivity+specificity-1. Interpretation: 0 means the test is useless, 1 means the test is perfect, and a value of > 0 means an appropriate use of information [Reference: Youden WJ. Index for rating diagnostic tests. Cancer. 1950;3(1):32–5]