Random-Effects Model (k = 9; tau^2 estimator: REML)

tau^2 (estimated amount of total heterogeneity): 46.3378 (SE = 60.3210)
tau (square root of estimated tau^2 value):      6.8072
I^2 (total heterogeneity / total variability):   39.16%
H^2 (total variability / sampling variability):  1.64

Test for Heterogeneity: 
Q(df = 8) = 11.3584, p-val = 0.1822

Model Results:

estimate       se     zval     pval    ci.lb    ci.ub          
-39.6275   3.8018 -10.4234   <.0001 -47.0788 -32.1761      *** 

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