Table 2.

Subgroup analyses of brain metastasis.

Subgroup	No. of studies	Pooled RR	95%CI	Heterogeneity I2; P-value	P-value for heterogeneity between subgroups
Pathology					0.21
SCC	3	0.16	0.05–0.55	0%; 0.60
Non-SCC	4	0.34	0.22–0.52	0%; 0.67
Prior treatment					0.92
Surgery	4	0.41	0.23–0.72	13%; 0.33
Non-surgery	5	0.39	0.26–0.59	7%; 0.37
Performance status					0.35
WHO 0–1	2	0.21	0.10–0.47	0% 0.71
WHO 2–3	2	0.51	0.10–2.65	0%; 0.72