Table 2. Pooled hazard ratios (HRs) for OS according to subgroup analyses.

Subgroup	No. of studies	No. of patients	Effects model	HR (95% CI)	P value	Heterogeneity
						I2 (%)	Ph
Overall	6	1718	Random	0.31 (0.20–0.47)	<0.001	74	0.002
Sample size
≥300	2	837	Random	0.23 (0.08–0.65)	0.005	84	0.01
<300	4	881	Random	0.34 (0.19–0.61)	<0.001	77	0.005
Cut-off for LMR
≥3	5	1510	Random	0.28 (0.17–0.48)	<0.001	78	0.001
<3	1	208	—	0.43 (0.26–0.71)	0.001	—	—
Type of publication
Full-text	5	1508	Random	0.27 (0.17–0.44)	<0.001	74	0.004
Abstract	1	210	—	0.35 (0.24–0.50)	0.006	—	—
NOS score
≥7	4	1300	Random	0.28 (0.17–0.48)	<0.001	78	0.001
<7	1	208	—	0.43 (0.26–0.71)	0.001	—	—