Table 2.

Comparison of readers’ MRI classification against true outcome (per breast)

	Ground truth result		Total	Kappa (95%CI)
	Cancer	Normal
Reader Classification
All Readers
Cancer	1776	1038	2814
No cancer	296	6140	6436
Total	2072	7178	9250	0.63 (0.61–0.65)
Group 1
Cancer	843	341	1184
No cancer	109	2957	3066
Total	952	3298	4250	0.72 (0.70–0.74)
Group 2
Cancer	933	697	1630
No cancer	187	3183	3370
Total	1120	3880	5000	0.56 (0.54–0.59)