Table 8. Meta-regression 3 .

Parameters	Coefficient	Standard errors	t	P>|t|	[95% Conf. Interval]
Sample size	0.001	< 0.01	0.93	0.35	[- 0.001, 0.002]
Constant	0.68	0.24	2.76	0.01	[0.17 , 1.18]
Meta-regression			Number of obs30
REML estimate of between-study variance			Tau2 = 0.5865
% residual variation due to heterogeneity			I-squared_res = 79.99%
Proportion of between-study variance explained			Adj R-squared = 2.24%