Table 3. Multivariate Cox proportional hazard model for assessing outcome-related factors.

Variable	BCSS			OS
	HR	95% CI	Pc	HR	95% CI	Pc
Age (years)
≥50	1			1
<50	0.974	0.778-1.218	0.815	0.773	0.643-0.929	0.006
Race			0.144			0.029
White	1			1
Black	1.051	0.811-1.362	0.709	1.047	0.855-1.283	0.655
Othera	0.606	0.359-1.023	0.061	0.569	0.370-0.876	0.010
Marital status
Married	1			1
Not marriedb	1.144	0.915-1.427	0.234	1.269	1.067-1.508	0.007
Grade
III	1			1
I/II	0.697	0.490-0.994	0.046	0.882	0.690-1.128	0.316
Tumor size			<0.001			<0.001
T1	1			1
T2	1.884	1.427-2.487	<0.001	1.644	1.338-2.019	<0.001
T3	3.735	2.653-5.259	<0.001	3.032	2.322-3.959	<0.001
Lymph node status			<0.001			<0.001
N0	1			1
N1	2.836	2.182-3.686	<0.001	2.024	1.650-2.482	<0.001
N2	3.311	2.260-4.850	<0.001	2.940	2.199-3.931	<0.001
N3	7.725	5.464-10.922	<0.001	5.599	4.228-7.415	<0.001
Type of surgery			<0.001			<0.001
Breast-conserving surgery	1			1
Mastectomy	1.167	0.902-1.510	0.240	1.208	0.986-1.480	0.069
None	2.810	1.800-4.387	<0.001	3.067	2.179-4.317	<0.001
Radiation therapy
No	1			1
Yes	0.659	0.520-0.835	0.001	0.582	0.481-0.704	<0.001

Abbreviation: CI, confidence interval.

^aOther includes American Indian/native Alaskan and Asian/Pacific Islander.

^bNot married includes divorced, separated, single (never married), unmarried or domestic partner and widowed.

^cP values were adjusted using a multivariate Cox proportional hazard regression model including all factors, as categorized in Table 3, and bold type indicates significance.