Table 2.

Calculation of the interobserver agreement (kappa coefficient)

			Pathologist 2			Total
			1+	2+	3+	1.00
Pathologist 1	1+	Count (n)	7	1	0	8
		Pathologist 1 (%)	87.5	12.5	0	100
		Pathologist 2 (%)	100	11.1	0	44.4
		% of Total	38.9	5.6	0	44.4
	2+	Count (n)	0	8	0	8
		Pathologist 1 (%)	0	100	0	100
		Pathologist 2 (%)	0	88	0	44.4
		% of Total	0	44	0	44.4
	3+	Count (n)	0	0	2	2
		Pathologist 1 (%)	0	0	100	100
		Pathologist 2 (%)	0	0	100	11.1
		% of Total	0	0	11.1	11.1
	Total	Count (n)	7	9	2	18
		Pathologist 1 (%)	38.9	50	11.1	100
		Pathologist 2 (%)	100	100	100	100
		% of Total	38.9	50	11.1	100
Symmetric measures
	Value	Standard error (a)	Approximate T (b)	Approximate significance
Kappa coefficient	0.906	0.092	4.894	0.00
Number of valid cases (n)	18

a Not assuming the null hypothesis.

b Using the asymptotic standard error assuming the null hypothesis.