Table 2. Cox proportional hazards model for analysis of disease-free survival.

		Univariate analysis			Multivariate analysis
Variable	Category	HR	95%CI	P value	HR	95%CI	P value
Sex	Male/female	1.610	0.9061–2.917	0.1039
Smoking	Ever/never	0.9400	0.4711–1.877	0.8622
Surgical procedure	Lobectomy/Wedge resection	0.6326	0.2484–1.360	0.2123	0.489	0.230–1.041	0.064
Pathologic stage	IA/IB	0.3445	0.1433–0.511	< 0.0001	0.382	0.206–0.709	0.002
Histology	Low/intermediate, high	0.3923	0.196–0.668	0.0012	0.465	0.252–0.859	0.015
EGFR mutation	Mutant/wild	1.353	0.6939–2.539	0.3941

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