Table S8. Multivariable Cox proportional hazards model 3 for OS.

Variables	Subgroups	P value	HR (95% CI)
Age, years	≥70 vs. <70	0.055	0.123 (0.014, 1.045)
Gender	Female vs. male	0.004	0.267 (0.109, 0.654)
Number of sites of metastases	>3 vs. ≤3	0.001	2.980 (1.539, 5.770)
Smoking history	Once or now smoking vs. non-smoker	0.717	0.862 (0.387, 1.921)
Radiotherapy history	Yes vs. no	0.942	1.022 (0.568, 1.839)
Surgical history	Yes vs. no	0.592	1.185 (0.636, 2.209)
Number of previous chemotherapy regimens	≥3 vs. 2	0.022	2.339 (1.131, 4.837)
	1 vs. 2	0.307	2.368 (0.454, 12.359)
ECOG	1 vs. 0	0.140	1.843 (0.818, 4.155)
Histology	Squamous vs. non-squamous	0.764	1.214 (0.342, 4.315)
Gefitinib	Yes vs. no	0.229	1.737 (0.707, 4.269)
Erlotinib	Yes vs. no	0.209	0.568 (0.235, 1.372)
Icotinib	Yes vs. no	0.393	1.558 (0.563, 4.317)
Afatinib	Yes vs. no	0.032	5.573 (1.156, 26.881)
Osimertinib	Yes vs. no	0.777	0.856 (0.293, 2.507)

OS, overall survival.