Table 2. Univariate and multivariate Cox regression analysis for overall survival in patients with colon cancer.

	Univariate analysis			Multivariate analysis
Characteristics	HR	95% CI	Pa	HR	95% CI	Pa
Age	1.00	0.99–1.01	0.932	—	—	—
Gender			0.815			—
Female	1.00	Reference		—	—
Male	1.02	0.87–1.20		—	—
BMI, kg m−2 b			0.073			—
<18.5	1.32	1.06–1.64		—	—
18.5–23.9	1.00	Reference		—	—
⩾24	0.89	0.73–1.11		—	—
Smoking statue			<0.001			<0.001
Never	1.00	Reference		1.00	Reference
Past	3.34	2.61–4.26		1.37	0.97–1.93
Current	13.31	10.75–16.48		8.07	6.20–10.51
Location			0.087			—
Left	1.00	Reference		—	—
Right	1.15	0.98–1.36		—	—
Grade			<0.001			0.002
Grade I	1.00	Reference		1.00	Reference
Grade II	1.19	0.82–1.73		1.96	1.34–2.86
Grade III	2.20	1.46–3.29		2.18	1.45–3.28
pTNM stage			<0.001			<0.001
Stage I	1.00	Reference		1.00	Reference
Stage II	4.42	2.74–7.14		2.43	1.48–4.00
Stage III	12.14	7.55–19.52		4.82	2.79–8.34
Operation			0.565			—
Elective	1.00	Reference		—	—
Emergencyc	1.11	0.79–1.53		—	—
Postoperative complication			0.71			—
No	1.00	Reference		—	—
Yesd	1.07	0.76–1.50			—	—
Adjuvant chemotherapy			<0.001			<0.001
Yes	1.00	Reference		1.00	Reference
No	2.01	1.70–2.36		1.43	1.21–1.69
ABO blood type			<0.001			<0.001
AB	1.00	Reference		1.000	Reference
Non-AB	2.70	1.67–4.38		3.22	1.98–5.22
O	2.47	1.51–4.05		2.78	1.69–4.56
B	2.65	1.61–4.37		2.99	1.81–4.96
A	3.04	1.80–5.03		4.37	2.65–7.20
Rh factor			0.573			—
Positive	1.00	Reference		—	—
Negative	1.33	0.49–3.55		—	—

Abbreviations: BMI=body mass index; 95% CI=95% confidence interval; HR=hazard ratio; pTNM stage=pathological tumour-node-metastasis stage.

^aCox proportional hazards model.

^bChinese definition.

^cEmergency includes lose blood, obstruction, and perforation.

^dPostoperative complication includes infection, anastomotic leak, and various reasons result in re-operation and/or prolonged hospitalisation.