Table 3. Exploration analysis and subgroup analysis.

Variables	Median DFS (months)	P value	Univariate analysis	P value	Multivariate analysis	P value
Stage I		0.12
Icotinib	NR		Reference		Reference
Erlotinib	62.4 (46.1–78.6)		1.81 (0.90–3.61)	0.10	2.00 (0.97–4.13)	0.06
Gefitinib	59.4 (NC)		1.76 (0.95–3.23)	0.07	1.79 (0.96–3.34)	0.07
Stage II		0.16
Icotinib	32.9 (6.3–59.5)		Reference		Reference
Erlotinib	64.8 (38.7–90.8)		0.40 (0.14–1.56)	0.09	0.39 (0.10–1.56)	0.18
Gefitinib	30.0 (23.6–36.5)		1.10 (0.45–2.69)	0.83	0.55 (0.19–1.58)	0.27
Stage III		0.96
Icotinib	32.9 (19.2–46.5)		Reference		Reference
Erlotinib	40.3 (25.7–54.7)		0.90 (0.47–1.72)	0.75	1.15 (0.56–2.38)	0.71
Gefitinib	36.7 (17.6–46.0)		0.97 (0.55–1.74)	0.93	1.81 (0.94–3.47)	0.08
Exon19 deletions		0.83
Icotinib	44.6 (12.1–77.1)		Reference		Reference
Erlotinib	43.5 (NC)		0.76 (0.31–1.88)	0.55	1.01 (0.36–2.88)	0.98
Gefitinib	39.5 (36.6–50.3)		0.92 (0.41–2.05)	0.83	0.75 (0.29–1.94)	0.55
Exon21 Leu858Arg		0.23
Icotinib	40.4 (NC–82.2)		Reference		Reference
Erlotinib	50.8 (22.0–79.5)		0.53 (0.23–1.22)	0.53	0.81(0.30-2.16)	0.67
Gefitinib	56.5 (37.7–75.2)		0.96 (0.44–2.09)	0.91	1.53(0.62-3.78)	0.35

NR, not reached; NC, not calculable.