highly significantP<0.0001
On meta-regression analysis, the combined impact of all covariates in the model explained at least some of the variance in effect size (Q = 16.21, df = 6, P= 0.0127), and the proportion of variance explained by covariates on comparing the model with and without the covariates was 73 % and highly significant (Tau2 = 0.1100, Tau = 0.3317, I2 = 86.5%, Q = .99, df = 10, P<0.0001) (R2 = 0.73).