Table 3.

Summary and subgroup analysis for the eligible studies

Analysis specification	No. of studies	Study heterogeneity		Effects model	Pooled HR(95% CI)	p-Value
		I2 (%)	Pheterogeneity
CSS
Overall	22	76.5	< 0.001	Random	1.37(1.23,1.53)	< 0.001
Geographical region
Asian	7	51.7	0.053	Random	1.34(1.12,1.59)	0.001
Other regions	15	80.8	< 0.001	Random	1.40(1.22,1.60)	< 0.001
Pathological types
ccRCC	6	0	0.775	Fixed	1.34(1.15,1.55)	< 0.001
Other types	16	81.7	< 0.001	Random	1.38(1.22,1.58)	< 0.001
Staging system
2010 AJCC	8	0	0.981	Fixed	1.30(1.17,1.44)	< 0.001
Other system	14	82.3	< 0.001	Random	1.42(1.23,1.64)	< 0.001
No. of patients
≥ 300	13	82	< 0.001	Random	1.39(1.21,1.61)	< 0.001
< 300	9	15,4	0.301	Fixed	1.33(1.16,1.51)	< 0.001
Median follow-up
≥ 40 months	12	83.3	< 0.001	Random	1.36(1.16,1.60)	< 0.001
< 40 months	9	30.2	0.177	Fixed	1.33(1.16,1.51)	< 0.001
OS
Overall	17	57.6	0.002	Random	1.29(1.20,1.40)	< 0.001
Geographical region
Asian	9	30.2	0.177	Fixed	1.38(1.25,1.51)	< 0.001
Other regions	8	58.6	0.017	Random	1.20(1.09,1.34)	< 0.001
Pathological types
ccRCC	8	48.8	0.057	Random	1.33(1.19,1.49)	< 0.001
Other types	9	62.7	0.006	Random	1.26(1.13,1.41)	< 0.001
Staging system
2010 AJCC	10	63.6	0.003	Random	1.30(1.17,1.44)	< 0.001
Other system	7	53.1	0.046	Random	1.30(1.14,1.47)	< 0.001
No. of patients
≥ 300	8	67.5	0.003	Random	1.25(1.12,1.39)	< 0.001
< 300	9	29.2	0.185	Fixed	1.35(1.22,1.49)	< 0.001
Median follow-up
≥ 40 months	13	62.6	0.001	Random	1.27(1.16,1.39)	< 0.001
< 40 months	4	0	0.412	Fixed	1.37(1.20,1.56)	< 0.001
RFS
Overall	9	35.6	0.133	Fixed	1.55(1.39,1.72)	< 0.001
Geographical region
Asian	6	42.7	0.12	Fixed	1.48(1.31,1.66)	< 0.001
Other regions	3	0	0.684	Fixed	1.87(1.41,2.37)	< 0.001
Pathological types
ccRCC	4	0	0.541	Fixed	1.61(1.40,1.86)	< 0.001
Other types	5	57.5	0.051	Random	1.46(1.25,1.71)	< 0.001
Staging system
2010 AJCC	5	54	0.069	Random	1.48(1.31,1.69)	< 0.001
Other system	4	0	0.483	Fixed	1.69(1.40,2.04)	< 0.001
No. of patients
≥ 300	4	0	0.702	Fixed	1.57(1.35,1.83)	< 0.001
< 300	5	63.4	0.027	Random	1.52(1.32,1.76)	< 0.001
Median follow-up
≥ 40 months	6	0	0.758	Fixed	1.62(1.43,1.84)	< 0.001
< 40 months	3	75.3	0.018	Random	1.39(1.16,1.68)	0.001
PFS
Overall	5	32.9	0.202	Fixed	1.31(1.17,1.46)	< 0.001
Pathological types
ccRCC	2	67.8	0.078	Random	1.44(1.20,1.71)	< 0.001
Other types	3	0	0.6	Fixed	1.23(1.07,1.41)	0.004
Staging system
2010 AJCC	2	76.3	0.04	Random	1.35(1.18,1.54)	< 0.001
Other system	3	0	0.582	Fixed	1.22(1.01,1.48)	0.036