Table 4.

Cox survival regression analysis of independent predictors of the overall survival in the 974 patients with colorectal cancer

Independent variables	P	Hazard ratio	95% Confidence interval
Age	0.15	1.011	1.002-1.020
ASA score	< 0.0001	1.477	1.29-1.69
Adjuvant chemotherapy	0.047	0.634	0.405-0.993
Stage I	< 0.0001	0.211	0.107-0.418
Stage II	0.003	0.397	0.214-0.738
Stage III	0.19	0.665	0.358-1.237
Stage IV	0.009	2.27	1.229-4.186
Colorectal surgical unit vs control	0.0005	0.667	0.531-0.837