Table 3. Multivariate model for malignancy. A multivariate log binomial regression model including all predictors was fitted to the data.

Variable	Relative risk	Lower 95% CI	Upper 95% CI	P-value
Strong family history: yes vs no	1.12	0.99	1.28	0.08
Age group (years)				0.14
50–59 vs <50	1.03	0.89	1.18	0.72
60–69 vs <50	0.96	0.82	1.11	0.58
70+ vs <50	1.11	0.93	1.32	0.24
60–69 vs 50–59	0.93	0.85	1.02	0.14
70+ vs 50–59	1.08	0.95	1.22	0.23
70+ vs 60–69	1.16	1.02	1.32	0.03
Screening round				<0.01
2–5 vs 1	1.42	1.27	1.58	<0.01
6+ vs 1	1.54	1.35	1.77	<0.01
6+ vs 2–5	1.09	0.98	1.21	0.11
Palpable mass: yes vs no	1.13	1.03	1.24	0.01
Radiological grade				<0.01
4 vs 3	2.20	1.94	2.51	<0.01
5 vs 3	3.26	2.90	3.65	<0.01
5 vs 4	1.48	1.36	1.61	<0.01
Distribution				0.52
Multiple vs single	0.96	0.84	1.10	0.57
Dispersed vs single	1.03	0.94	1.13	0.51
Dispersed vs multiple	1.07	0.95	1.22	0.28
Size >15 vs 15 or less	1.29	1.17	1.44	<0.01