Table 5– Factors associated with overall survival

	Overall survival months	Univariate analysis p-value	Multivariate analysis
	Overall survival months		HR	95% CI	p-value
Age
<60 years	20.1 (15.1–25.0)	0.113
>60 years	14.2 (7.3–21.1)
Sex
Female	22.7 (16.8–28.5)	0.012	1.588	0.860–2.93	0.139
Male	14.2 (11.9–16.5)
ECOG
0–1	20.7 (16.3–25.2)	<0.001	2.04	1.168–3.56	0.012
2–4	10.6 (8.7–12.5)
Stage
III	24.3 (8.5–40.1)	0.029	2.16	1.08–4.30	0.029
IV	15.0 (9.6–20.4)
Smoking status
Positive	24.3 (19.4–29.2)	0.046	1.204	0.661–2.19	0.544
Negative	14.4 (12.3–16.5)
Wood smoke exposure
Positive	15.2 (9.7–20.7)	0.921
Negative	20.4 (13.8–27.1)
EGFR status
Positive	27.3 (11.5–43.1)	0.027	1.999	1.142–3.498	0.015
Negative	14.8 (11.3–18.3)
Groups
Intermediate	16.8 (11.8–21.8)	0.023	0.804	0.624–1.036	0.037
High	25.0 (15.4–34.6)

Data are presented as median (95% CI), unless otherwise stated. HR: hazard ratio; ECOG: Eastern Cooperative Oncology Group; EGFR: epidermal growth factor receptor.