Table 1.

Agreement, Gwet’s AC2 (GAC2), and Krippendorff’s alpha (KA) coefficients per histopathological feature

Histopathological feature	Agreement (%)	95% CI (%)	GAC2	95% CI	KA	95% CI
Grade (1, 2 or 3)	76.4	75.27–77.52	0.52	0.50–0.55	0.34	0.30–0.39
Grade (1 versus 2 + 3)	83.5	81.33–85.68	0.78	0.74–0.82	0.35	0.28–0.42
Grade (1 + 2 versus 3)	69.3	66.94–71.63	0.43	0.38–0.49	0.34	0.29–0.38
Grade (low versus high)	72.8	70.54–75.12	0.52	0.47–0.57	0.38	0.32–0.44
Dominant growth pattern	84.8	82.58–86.97	0.78	0.75–0.82	0.44	0.37–0.51
Calcifications	81.1	78.81–83.40	0.70	0.65–0.75	0.49	0.43–0.54
Necrosis	81.4	79.12–83.64	0.70	0.66–0.75	0.47	0.41–0.53
Mitotic activity	78.5	76.12–80.97	0.70	0.65–0.74	0.24	0.19–0.29
Periductal fibrosis (absent, subtle or prominent presence)	70.9	69.71–72.13	0.37	0.34–0.39	0.25	0.22–0.29
Periductal fibrosis (present versus absent)	71.2	68.82–73.48	0.53	0.48–0.58	0.23	0.18–0.28
Type of periductal fibrosis (if present)	70.5	67.57–73.37	0.50	0.44–0.57	0.26	0.21–0.31
Lymphocytic infiltrate (absent, subtle or prominent presence)	77.1	75.82–78.36	0.50	0.47–0.53	0.42	0.38–0.47
Lymphocytic infiltrate (present versus absent)	73.0	70.51–75.40	0.51	0.45–0.56	0.38	0.33–0.43

GAC2 Gwet’s AC2, KA Krippendorff’s alpha, weighted analysis was performed for ordinal features with more than 2 categories using linear weights (grade 1–3, periductal fibrosis, and lymphocytic infiltrate), CI confidence interval