Table 2.

Confusion matrices for intra-expert agreement in retinopathy of prematurity plus disease grading of 34 wide-angle images by 4 repeat experts, who participated in both 2016 and 2007. For each repeat expert, the p-value for plus disease grading between 2016 vs. 2007 is shown, followed by the weighted κ statistic for intra-expert agreement between 2016 vs. 2007.

		2016 Diagnosis
		Normal	Pre-plus	Plus
Expert 1: P = 0.002, κ = 0.270
2007 Diagnosis	Normal	0	1	2
	Pre-Plus	0	3	8
	Plus	0	0	20
Expert 2: P = 0.021, κ = 0.478
2007 Diagnosis	Normal	4	9	0
	Pre-Plus	2	8	1
	Plus	0	0	10
Expert 3: P = <0.001, κ = 0.094
2007 Diagnosis	Normal	0	3	9
	Pre-Plus	0	3	10
	Plus	0	0	9
Expert 4: P = <0.001, κ = 0.285
2007 Diagnosis	Normal	7	0	0
	Pre-Plus	7	4	0
	Plus	0	10	6