Table 2. BI-RADS density scores: inter-rater agreement and reliability (n = 992).

		% (N)
	ᴋw (95% CI)	% agreement	% agreement (a+b vs. c+d)
Rater 1 vs. 2	0.81 (0.78–0.83)	74.3 (737)	90.2 (895)
Rater 1 vs. 3	0.84 (0.82–0.86)	72.1 (715)	89.0 (883)
Rater 2 vs. 3	0.80 (0.78–0.82)	67.6 (671)	89.9 (892)
Rater 1 vs. majority	0.93 (0.91–0.94)	89.0 (883)	94.7 (939)
Rater 2 vs. majority	0.89 (0.87–0.91)	84.8 (841)	95.6 (948)
Rater 3 vs. majority	0.91 (0.89–0.92)	82.8 (821)	94.4 (936)

ᴋ_w = weighted kappa scores (Fleiss-Cohen, quadratic weights), CI = confidence interval