Table 3.

Risk factors for PFS analyzed by univariate Cox regression model

Characteristics	HR	95% CI	p
Sex (female/male)	1.678	0.910–3.096	0.097
Age (>60 years/£60 years)	1.349	0.754–2.412	0.313
Smoking history (never/ever)	2.118	0.253–5.958	0.155
EGFR mutation (21mutation/19 deletion)	0.288	0.115–0.538	0.00094

Abbreviations: PFS, progression-free survival; HR, hazard ratio; CI, confidence interval; EGFR, epidermal growth factor receptor.