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Table 1 Inter-observer agreement on the BI-RADS density classification

From: Inter-observer agreement according to three methods of evaluating mammographic density and parenchymal pattern in a case control study: impact on relative risk of breast cancer

 

Reader 2

Reader 1

D1

D2

D3

D4

Total

High/low-risk

D1

131

(282)

1

(7)

0

(0)

0

(0)

132

(289)

229; 60%

D2

15

(40)

81

(160)

1

(4)

0

(0)

97

(204)

(493; 64%)

D3

0

(0)

46

(80)

58

(113)

0

(3)

104

(196)

155; 40%

D4

0

(0)

1

(1)

23

(36)

27

(39)

51

(76)

(272; 36%)

Total

146

(322)

129

(248)

82

(153)

27

(42)

384

(765)

P<0.0001

High/low-risk

275; 72%

(570; 75%)

109; 28%

(195; 25%)

  

Agreement

Women (%)

Breasts (%)

  

Absolute agreement:

77.3

77.6

  

D1/D2 disagreement:

4.2

6.1

  

D2/D3 disagreement:

12.2

11.0

  

D3/D4 disagreement:

6.0

5.1

  

Two-grade disagreement:

0.3

0.1

  

High/low-risk agreement:

87.5

88.9

  
  1. Based on 384 women (breasts are shown in brackets; n=765).
  2. Numbers in boldface indicate agreement between the two readers.