Table 2. Univariable and multivariable analysis of progression-free survival.

	Univariable analysis			Multivariable analysis
	n	PFS (months)	P-value	Hazard ratio	P-value	95% CI
Age, years			0.204
>65	134	11.3
≤65	135	10.0
Sex			0.702
Male	113	10.3
Female	156	10.5
Diabetes mellitus			0.602
Yes	51	10.3
No	218	10.3
Smoking history			0.683
Never	182	10.6
Former / current	87	9.8
Performance status			<0.001		0.006
ECOG 0–2	242	11.3		1
ECOG 3–4	27	2.9		2.16		1.20–2.98
EGFR mutation			<0.001		<0.001
Common	242	11.3		1
Uncommon	27	5.1		2.76		1.77–4.32
Tumor type			0.104
Adenocarcinoma	247	10.6
Non-adenocarcinoma	22	9.0
Brain metastasis			0.001		0.180
Yes	64	7.4		1.25		0.90–1.73
No	205	12.0		1
Bone metastasis			<0.001		<0.001
Yes	119	7.8		1.78		1.32–2.40
No	150	13.5		1
Liver metastasis			<0.001		0.005
Yes	35	6.7		1.80		1.20–2.71
No	234	11.3		1
Pleura metastasis			0.007		0.004
Yes	129	9.0		1.49		1.14–1.94
No	140	11.8		1
Antacid			0.234
Proton pump inhibitor	18	6.7
H2 receptor antagonists	39	9.4
None	212	11.2

PFS, progression-free survival; CI, confidential interval; ECOG, Eastern Cooperative Oncology Group; EGFR, epidermal growth factor receptor.