Table 5.

Discrimination performance of final model and sub models in comparison to established risk models

Model	AUCa	95% CI	LRb
1. Percentage mammographic density, age at mammography, BMI	0.63	0.60–0.65	109.2
2. Model 1 + family history of breast cancer, HRT use	0.64	0.62–0.67	122.0
3. Model 2 + absolute differences for calcifications, masses, density	0.70	0.68–0.72	193.7
4. Model 3 + interaction between percentage density and masses	0.71	0.69–0.73	233.6
Established risk models for comparison
Tyrer-Cuzickc	0.63	0.60–0.65	88.2
Gaild	0.56	0.53–0.58	34.9

BMI Body mass index, HRT Hormone replacement therapy, LR Likelihood ratio

^aAUC was evaluated for the absolute risks of stated models

^bChi-square test of β = 0

^cTyrer-Cuzick model included risk factors of age, age at menarche, age at first child, menopause, length, weight, HRT, hyperplasia, atypical hyperplasia, lobular cancer in situ, and first-/second-degree family history of breast cancer. Data coding was done according to the Tyrer-Cuzick protocol

^dGail model included risk factors of age, age at menarche, age at first live birth, number of previous breast biopsies, atypical hyperplasia, and first-degree family history of breast cancer. Data coding was done according to the Gail protocol