Table 2 

Cox proportional hazards model of survival in all patients 

Variable 
B 
SE 
Wald 
df 
Sig. 
Exp(B) 


Age at diagnosis 
.019 
.012 
2.661 
1 
.103 
1.019 


Category 
.566 
.355 
2.539 
1 
.111 
.568 


Tumour size 
.022 
.007 
8.981 
1 
.003* 
1.022 


Tumour grade 
.097 
.095 
1.027 
1 
.311 
1.101 


Histological type 
.062 
.105 
.353 
1 
.552 
.939 


Tumour invasion 
.009 
.159 
.003 
1 
.956 
1.009 


Nodal status 
.131 
.089 
2.165 
1 
.141 
1.140 


Distant metastasis 
.107 
.272 
.154 
1 
.695 
1.113 


ER receptors status 
.039 
.036 
1.161 
1 
.281 
1.040 


PR receptors status 
.119 
.051 
5.351 
1 
.021* 
1.126 


HER2 status 
.090 
.056 
2.591 
1 
.107 
.914 


Hormonal therapy 
.264 
.389 
.462 
1 
.497 
.768 


Chemotherapy 
.007 
.079 
.008 
1 
.927 
.993 


Radiotherapy 
.003 
.010 
.071 
1 
.790 
.997 


Surgical treatment 
.011 
.209 
.003 
1 
.957 
1.011 


The output of this analysis includes the unstandardized regression coefficient (B), the standard error of B and its Wald test significance value, the degrees of freedom and the significance value of the coefficient. If the significance value for the coefficient is more than 0 050, then the covariate effect cannot be assumed to be different from 0. The predicted change in the hazard per unit increase in the covariate is Exp (B); if the value is less than 1, then the direction of the effect is towards reducing the hazard rate. To be considered to have a significant effect on the hazard rate, the 95 per cent confidence interval for the Exp (B) should not include 1. Category = less than 40 yrs group vs. more than 40 yrs group (*) = significant values. df = degree of freedom B = unstandardized regression coefficient; Exp (B) = predicted change in the hazard per unit increase in the covariate 

Kheirelseid et al. BMC Cancer 2011 11:383 doi:10.1186/1471240711383 