highly significantP < 0.01
Highly significant heterogeneity was found among the 13 studies ( χ 2 = 262.30, I 2 = 95%, P < 0.01), indicating their heterogeneity.
Highly significant heterogeneity was found among the 13 studies ( χ 2 = 262.30, I 2 = 95%, P < 0.01), indicating their heterogeneity.
The combined mean difference for these four studies did not reach statistical significance (SMD = − 1.71; 95% CI [−3.67, 0.24]; P = 0.09; n = 314) ( Figure 8 ). 3.8.