Table 3. Subgroup and meta-regression analyses between NLR and OS.

Variables	Number of outcomes	HR [95% CI]	P value	Heterogeneity		Model	P3-value of Meta-regression
				I2 (%)	P2 value		Univariate	Multivariate
(1) Ethnicity							0.329	0.762
Asian	14	1.35 [1.22–1.51]	< 0.00001	61	0.001	random
Caucasian	7	1.40 [1.16–2.21]	0.005	71	0.002	random
(2) Cut-off value							0.659	0.476
< 4.0	12	1.30 [1.21–1.39]	< 0.00001	40	0.08	fixed
≥ 4.0	9	1.36 [1.11–1.67]	0.003	78	< 0.0001	random
(3) Sample size							0.017	0.031
N < 150	6	1.89 [1.50–2.38]	< 0.00001	0	0.73	fixed
150 < N ≤ 200	6	1.26 [1.16–1.36]	< 0.00001	30	0.21	fixed
N > 200	9	1.34 [1.11–1.59]	0.002	77	< 0.0001	random
(4) Clinical stage							0.563	0.925
L	5	1.47 [1.03–2.10]	0.04	75	0.003	random
E	3	1.51 [1.08–2.10]	0.02	72	0.03	random
L + E	13	1.38 [1.22–1.57]	< 0.00001	61	0.002	random

L:limited stage; E:extensive stage