Table 4.

Frequency of true positives (TP), false positives (FP), true negatives (TN), and false negative (FN) as a function of four various probe positive threshold criteria

Threshold criteria method	TP	FP	TN	FN
3-Sigma Statistical	228	31	47	95
4.3-Sigma Statistical	211	25	53	112
1.5-to-1 Ratiometric	138	12	66	185
1.33-to-1 Ratiometric	183	17	61	140