Table 3.

The results of stratified analysis in meta-analysis for OS and DFS/PFS

Outcome	Stratified analysis	No. of studies	HR (95% CI)	P	Heterogeneity		Model used
					I² (%)	Ph
OS	Analysis of variable
	Univariate	9	1.65(1.45-1.87)	<0.001	59.50%	0.011	Random
	Multivariate	13	1.35(1.19-1.54)	<0.001	59.00%	0.004	Random
	Ethnicity
	Asian	12	1.36(1.19-1.55)	<0.001	62.40%	0.002	Random
	non-Asian	3	1.48(1.22-1.81)	<0.001	0.00%	0.622	Fixed
	Cut-off value
	<400mg/dl	5	1.23(1.09-1.38)	<0.001	29.30%	0.226	Fixed
	≥400mg/dl	9	1.48(1.34-1.64)	<0.001	0.00%	0.616	Fixed
	Tumor stage
	I-III	5	1.24(0.99-1.55)	0.058	73.20%	0.005	Random
	III-IV	3	1.41(1.22-1.62)	<0.001	0.00%	0.54	Fixed
	Histology
	NSCLC	9	1.32(1.14-1.53)	<0.001	66.70%	0.002	Random
	SCLC	2	1.64(1.13-2.37)	0.01	46.10%	0.173	Fixed
	NSCLC+SCLC	4	1.49(1.26-1.75)	<0.001	0.00%	0.813	Fixed
	Quality score
	>6	10	1.36(1.17-1.59)	<0.001	64.50%	0.003	Random
	≤6	5	1.37(1.21-1.56)	<0.001	28.40%	0.232	Fixed
DFS/PFS	Analysis of variable
	Univariate	5	1.43(1.31-1.57)	<0.001	0.00%	0.527	Fixed
	Multivariate	7	1.29(1.01-1.65)	0.042	74.90%	0.001	Random
	Cut-off value
	<400mg/dl	2	1.07(0.93-1.23)	0.36	0.00%	0.407	Fixed
	≥400mg/dl	4	1.74(1.36-2.23)	<0.001	22.80%	0.247	Fixed
	Tumor stage
	I-III	6	1.24(0.97-1.57)	0.08	75.30%	0.001	Random
	Histology
	NSCLC	6	1.24(0.97-1.57)	0.08	75.30%	0.001	Random
	SCLC	1	-	-	-	-	-
	Quality score
	>6	4	1.13(0.85-1.51)	0.387	75.20%	0.007	Random
	≤6	3	1.65(1.00-2.73)	0.051	69.00%	0.04	Random

OS: overall survival; DFS: disease-free survival; PFS: progress-free survival; NSCLC: non-small cell lung cancer; SCLC: small cell lung cancer; HR: hazard ratio; CI: confidence interval