Table 2.

Cox regression analyses of prognostic variables for OS

Variables	Univariate cox regression		Multivariate cox regression
	HR (95% CI)	p value	HR (95% CI)	p value
Sex
Male	1.193 (1.023–1.393)	0.025	1.209 (1.035–1.413)	0.017
Female	1		1
Age		< 0.001		< 0.001
≤ 60	0.550 (0.449–0.673)	< 0.001	0.492 (0.400–0.605)	< 0.001
> 60, ≤ 70	0.699 (0.586–0.833)	< 0.001	0.747 (0.624–0.895)	0.002
> 70	1		1
Marital status
Unmarried	1.000 (0.856–1.168)	0.998	–	–
Married	1		–	–
Lateral			–	–
Left	1.019 (0.873–1.189)	0.810	–	–
Right	1		–	–
Primary site		0.282		–
Upper lobe	1		–
Lower lobe	1.054 (0.885–1.256)	0.556	–	–
Other	1.205 (0.956–1.519)	0.114	–	–
Grade		0.095	–	–
I–II	0.625 (0.414–0.945)	0.026	–	–
III	0.875 (0.726–1.055)	0.163	–	–
IV	0.865 (0.713–1.049)	0.140	–	–
Unknown	1		–	–
T stage		< 0.001		< 0.001
T1	1		1
T2	1.267 (1.062–1.511)	0.009	1.253 (1.046–1.501)	0.015
T3–T4	2.106 (1.725–2.572)	< 0.001	2.000 (1.622–2.467)	< 0.001
Surgery		< 0.001		< 0.001
Lobectomy	1		1	< 0.001
Sublobectomy	1.659 (1.415–1.944)	< 0.001	1.444 (1.194–1.747)	< 0.001
Pneumonectomy	2.006 (1.381–2.915)	< 0.001	1.556 (1.060–2.285)	0.024
N stage		< 0.001		0.022
N0	1		1
N1	1.570 (1.292–1.908)	< 0.001	1.529 (1.064–2.196)	0.022
N2	1.865 (1.548–2.246)	< 0.001	1.572 (1.139–2.170)	0.006
LNR		< 0.001		0.005
< 0.01	1		1
> 0.01	1.894 (1.590–2.256)	< 0.001	1.310 (0.921–1.864)	0.1330
NO*	2.177 (1.771–2.676)	< 0.001	1.537 (1.186–1.992)	0.001
Radiation				–
No	1		–	–
Yes	1.008 (0.862–1.179)	0.919	–	–
Chemotherapy
No	1.254 (1.064–1.476)	0.007	1.525 (1.282–1.815)	< 0.001
Yes	1		1

CI confidence interval, HR hazard ratio, OS overall survival, LNR lymph node metastatic ratio, NO* no lymph node resected