Table 5.

Univariate and multivariate analysis of risk factors for overall survival with proportional hazard model

	Univariate analysis			Multivariate analysis
	HR	95%CI	P value	HR	95%CI	P value
Smoking history
No	Ref			Ref
Yes	1.674	1.091 ~ 2.567	0.018	0.877	0.367 ~ 2.098	0.589
Smoking index
<20	Ref			Ref
≥20	1.685	1.133 ~ 2.505	0.010	1.008	0.461 ~ 2.202	0.942
ECOG PS score
0 ~ 1	Ref			Ref
≥2	1.709	1.47 ~ 2.548	0.008	1.107	0.471 ~ 2.604	0.717
Initial treatment
Surgery	Ref			Ref
Radiation	3.413	1.905 ~ 6.116	<0.0001	1.798	0.692 ~ 4.671	0.638
Chemotherapy	10.589	5.488 ~ 20.429	<0.0001	3.191	1.288 ~ 7.908	0.080
Target therapy	3.027	1.570 ~ 5.835	0.001	1.332	0.457 ~ 3.881	0.189
BSC	4.132	2.141 ~ 7.976	<0.0001	2.299	0.782 ~ 6.754	0.119
Hemoptysis	2.052	1.201 ~ 3.507	0.009	1.165	0.569 ~ 2.385	0.092
Neurologic symptom	3.501	1.325 ~ 7.927	0.009	2.497	0.826 ~ 7.551	0.113
Cardiovascular disease	1.763	1.158 ~ 2.684	0.008	1.089	0.628 ~ 1.888	0.397
Presence of COPD
Non‐COPD	Ref			Ref
COPD	2.059	1.362 ~ 3.115	0.001	1.619	1.098 ~ 2.314	0.030
Age	1.049	1.024 ~ 1.075	<0.001	1.077	1.050 ~ 1.105	<0.0001
TNM stage
Ⅰ	Ref			Ref
Ⅱ	0.493	0.118 ~ 2.059	0.332	0.609	0.134 ~ 2.755	0.519
Ⅲ	4.583	2.862 ~ 7.339	<0.0001	5.513	3.306 ~ 9.196	<0.0001
Ⅳ	6.886	4.111 ~ 11.536	<0.0001	11.743	6.507 ~ 21.191	<0.0001
Histology subtype
Non‐SCC	Ref			Ref
SCC	2.358	1.517 ~ 3.663	<0.0001	3.106	1.949 ~ 4.926	<0.0001
Cough	1.984	1.171 ~ 3.362	0.011	2.463	1.415 ~ 4.286	0.001
Serum level of CEA, ng/ml	1.001	1.000 ~ 1.002	0.005	1.001	1.000 ~ 1.001	0.023
Neutrophil‐Lymphocyte Ratio	2.452	1.837 ~ 3.114	<0.0001	2.615	1.476 ~ 4.832	0.007

Abbreviations: BSC, best supportive care; CEA, carcinoembryonic antigen; COPD, chronic obstructive pulmonary disease; ECOG PS, Eastern Cooperative Oncology Group performance status; NLR, neutrophil‐lymphocyte ratio.