Table 2.

Meta-regression analysis of the heterogeneity of the basic characteristics.

Covariatesa	ESb	Coefficient	95% CI	P value
Male	24	− 0.418	− 1.152 to 0.316	0.264
Median age	27	0.014	− 0.004 to 0.032	0.116
Median KPS	14	− 0.002	− 0.014 to 0.011	0.811
EGOG ≤ 1	13	− 0.092	− 0.421 to 0.604	0.726
Multiple sites	17	0.085	− 0.369 to 0.539	0.715
DLBCL	18	0.046	− 0.562 to 0.655	0.882
CSF cytology	20	0.236	− 0.214 to 0.685	0.305
CSF protein	10	0.014	− 0.599 to 0.628	0.964
Ocular	22	0.171	− 0.403 to 0.745	0.560
Single dose of MTX (mg/m2)	29	− 0.013	− 0.041 to 0.014	0.350
The number of Cycles	29	0.051	0.007 to 0.095	0.025
CR best	28	0.003	− 0.000 to 0.006	0.096

ES effect size, CI confidence interval.

^aAll of the data in this analysis are presented in Table 1.

^bNumber of studies used in the regression model.