Table 4.

Performance of the assay for different histological types

	Training*		Validation, entire set		Validation, agreement set
Histological type	#Samples†	% Correct‡	#Samples†	% Correct‡	#Samples†§	% Correct‡
Medullary	5	100 [48–100]	3	100 [29–100]	1 (33.3%)	100 [3–100]
PTC classic	48	94 [83–100]	17	88 [64–99]	15 (88.2%)	100 [78–100]
FVPTC	40	81 [65–92]	37	84 [68–94]	23 (62.2%)	96 [78–100]
FC	16	56 [30–80]	3	67 [9–99]	1 (33.3%)	100 [3–100]
PDC	5	100 [48–100]	1	100 [3–100]	0 (0%)	NA
Papillary, other	6	100 [54–100]	0	NA	0	NA
FA	90	76 [66–84]	95	76 [66–84]	82 (86.3%)	82 [72–89]
Nodular hyperplasia	48	75 [60–86]	28	64 [44–81]	23 (82.1%)	74 [52–90]
CLT	9	82 [44–99]	5	40 [5–85]	5 (100.0%)	40 [5–85]
Total	267		189		150

*Only indeterminate training samples are listed in the table. Estimates for the training performance are based on the mean of 10 10-fold cross-validation runs. Samples with very low expression in any of the classification steps, as well as medullary samples, are not included.

†Number of samples includes only those that passed quality control steps.

‡95% CIs are in square brackets.

§Numbers in parentheses signify the percentage of test samples in the agreement set.

CLT, chronic lymphocytic thyroiditis; FA, follicular adenoma; FC, follicular carcinoma; FVPTC, follicular variant of papillary carcinoma; NA, not applicable; PDC, poorly differentiated carcinoma.