Table 2.

Univariable and multivariable analyses of overall survival in patients after propensity score matching.

Characteristics	Total (N)	Univariate analysis		Multivariate analysis
		HR (95% CI)	P value	HR (95% CI)	P value
Age
<65	260	Reference		Reference
≥65	184	1.446 (1.014-2.060)	0.041	1.453 (0.998-2.117)	0.051
Gender
Male	344	Reference		Reference
Female	100	0.704 (0.448-1.105)	0.127	0.884 (0.504-1.550)	0.667
Histology
Adenocarcinoma	237	Reference		Reference
Squamous	207	1.005 (0.712-1.416)	0.979	1.021 (0.697-1.495)	0.915
Disease stage
IIIB/IIIC	100	Reference		Reference
IV	344	1.094 (0.716-1.671)	0.679	0.848 (0.533-1.349)	0.486
ECOG PS			0.121		0.218
0-1	206	Reference		Reference
≥2	14	1.667 (0.764-3.638)	0.199	1.374 (0.590-3.199)	0.461
Unknown	224	0.790 (0.555-1.126)	0.193	0.756 (0.511-1.118)	0.161
Smoking status			0.860		0.604
Current smoker	35	Reference		Reference
Former smoker	167	0.946 (0.465-1.923)	0.878	0.882 (0.424-1.834)	0.736
Never smoker	121	0.794 (0.379-1.664)	0.542	0.693 (0.310-1.553)	0.373
Unknown	121	0.907 (0.435-1.893)	0.796	1.021 (0.471-2.215)	0.958
PD-L1 expression			0.954		0.967
<50%	42	Reference		Reference
≥50%	31	1.082 (0.482-2.428)	0.849	0.912 (0.397-2.099)	0.829
Unknown	371	0.982 (0.550-1.752)	0.951	0.992 (0.547-1.797)	0.978
Brain metastases
Yes	122	Reference		Reference
No	326	0.739 (0.509-1.074)	0.113	0.765 (0.511-1.144)	0.192
Liver metastases
Yes	147	Reference		Reference
No	297	0.636 (0.449-0.900)	0.011	0.647 (0.446-0.939)	0.022
Bone metastases
Yes	262	Reference		Reference
No	182	0.699 (0.482-1.013)	0.058	0.681 (0.453-1.025)	0.066
Therapy
ICI-mono	222	Reference		Reference
ICI-chemo	222	0.495 (0.344-0.712)	<0.001	0.488 (0.337-0.707)	<0.001

ECOG PS, Eastern Cooperative Oncology Group performance status; PD-L1, programmed death ligand 1; HR, hazard ratio.