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Table 2 Kappa (κ)-statistics according to the BI-RADS and Tabár 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

 

Agreement

absolute (%)

Total

κ (95% CI)

Cases

κ (95% CI)

Controls

κ (95% CI)

Left

κ (95% CI)

Right

κ (95% CI)

Total

ICC* (95% CI)

Breasts

n=765

n=765

n=242

n=523

n=383

n=382

n=765

BI-RADS

       

4-categories

77.6

0.68

(0.64-0.72)

0.65

(0.57-0.73)

0.69

(0.64-0.74)

0.71

(0.66-0.77)

0.65

(0.59-0.71)

0.88

(0.81-0.92)

Low/high-risk

88.9

0.74

(0.68-0.79)

0.75

(0.66-0.83)

0.72

(0.65-0.78)

0.74

(0.66-0.81)

0.75

(0.67-0.82)

-

Tabár

       

5-categories

74.5

0.64

(0.60-0.69)

0.56

(0.47-0.63)

0.67

(0.62-0.72)

0.70

(0.64-0.75)

0.59

(0.53-0.65)

-

Low/high-risk

88.2

0.70

(0.63-0.80)

0.72

(0.63-0.80)

0.67

(0.58-0.75)

0.75

(0.69-0.82)

0.65

(0.55-0.73)

-

Women

n=384

n=384

n=122

n=262

  

n=384

BI-RADS

       

4-categories

77.3

0.68

(0.63-0.74)

0.60

(0.49-0.71)

0.72

(0.65-0.78)

  

0.89

(0.79-0.93)

Low/high-risk

87.5

0.73

(0.66-0.79)

0.69

(0.57-0.81)

0.73

(0.63-0.81)

  

-

Tabár

       

5-categories

74.7

0.65

(0.59-0.71)

0.55

(0.44-0.67)

0.69

(0.61-0.75)

  

-

Low/high-risk

89.6

0.77

(0.70-0.84)

0.80

(0.69-0.90)

0.73

(0.63-0.83)

  

-

  1. Kappa values are based on 765 breasts and 384 women, respectively.
  2. *ICC (two-way random, single measure) corresponding to the weighted kappa value.