Random-Effects Model (k = 58; tau^2 estimator: REML)

tau^2 (estimated amount of total heterogeneity): 197.4919 (SE = 60.4085)
tau (square root of estimated tau^2 value):      14.0532
I^2 (total heterogeneity / total variability):   68.99%
H^2 (total variability / sampling variability):  3.22

Test for Heterogeneity: 
Q(df = 57) = 202.1339, p-val < .0001

Model Results:

estimate       se     zval     pval    ci.lb    ci.ub          
-54.9734   2.4140 -22.7726   <.0001 -59.7048 -50.2420      *** 

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Signif. codes:  0 *** 0.001 ** 0.01 * 0.05 . 0.1   1 