Table 2. Subgroup analysis of pooled hazard ratios for overall survival.

Subgroup	HR (95% CI)	P value	Meta-regression P value	Heterogeneity
				I2 (%)	P value
PLR
Year of publication			0.284
2016–2017	1.78 (1.23–2.57)	0.002		67.8	0.008
2013–2015	1.86 (1.53–2.25)	< 0.001		0.0	0.635
Region			0.295
Asia	2.00 (1.15–3.47)	0.014		73.7	0.004
Non-Asia	1.80 (1.52–2.12)	< 0.001		0.0	0.709
Stage			0.178
Mixed	1.43 (1.20–1.69)	< 0.001		19.4	0.293
Metastatic	1.97 (1.44–2.70)	< 0.001		58.5	0.034
Sample size			0.726
> 200	1.60 (1.40–1.82)	< 0.001		37.2	0.174
< 200	2.17 (1.18–3.99)	0.012		70.1	0.010
Cut-off value			0.653
> 160	1.59 (1.39–1.82)	< 0.001		18.5	0.297
< 160	2.22 (1.24–3.99)	0.007		72.8	0.007
ROC curve			0.240
Considered	1.96 (1.04–3.66)	0.036		78.8	0.003
Not considered	1.81 (1.54–2.13)	< 0.001		0.0	0.774
Analysis of hazard ratio			0.786
Univariate	1.60 (1.40–1.83)	< 0.001		37.6	0.171
Multivariable	2.12 (1.21–3.71)	0.009		70.4	0.009
LMR
Year of publication			0.771
2016–2017	0.68 (0.59–0.80)	< 0.001		44.7	0.143
2014–2015	0.58 (0.35–0.96)	0.032		60.3	0.112
Histology			0.099
Mixed	0.75 (0.63–0.89)	0.001		0.0	0.657
Clear cell	0.54 (0.44–0.68)	< 0.001		12.3	0.331
Sample size			0.365
> 600	0.70 (0.60–0.82)	< 0.001		31.4	0.233
< 600	0.54 (0.39–0.73)	< 0.001		39.7	0.190
Cut-off value			0.515
> 3.0	0.66 (0.47–0.93)	0.017		52.6	0.121
= 3.0	0.58 (0.45–0.74)	< 0.001		20.1	0.286
ROC curve			0.082
Considered	0.72 (0.62–0.84)	< 0.001		0.0	0.399
Not considered	0.48 (0.35–0.65)	< 0.001		0.0	0.665
Analysis of hazard ratio			0.779
Univariate	0.64 (0.45–0.92)	0.016		64.9	0.091
Multivariable	0.61 (0.47–0.77)	< 0.001		37.5	0.187

HR, hazard ratio; CI, confidence interval. PLR, platelet to lymphocyte ratio. LMR, lymphocyte to monocyte ratio.