Table 4. Cox proportional hazards model for analysis of overall survival.

		Univariate analysis			Multivariate analysis
Variable	Category	HR	95%CI	P value	HR	95%CI	P value
Sex	Male/female	1.232	0.4608–3.307	0.6758
Smoking	Ever/never	1.047	0.3334–3.291	0.9367
Surgical procedure	Lobectomy/Wedge resection	3.019	0.5732–7.906	0.2598	1.934	0.248–15.088	0.529
Pathologic stage	IA/IB	0.1413	0.050–0.3773	0.0002	0.222	0.060–0.824	0.024
Histology	Low/intermediate, high	0.1008	0.0491–0.3894	0.0003	0.164	0.035–0.768	0.022
EGFR mutation	Mutant/wild	1.567	0.4923–4.528	0.4792

CI, confidence interval; EGFR, epidermal growth factor receptor; HR, hazard ratio.