Random-Effects Model (k = 8; tau^2 estimator: REML)

tau^2 (estimated amount of total heterogeneity): 0 (SE = 48.2101)
tau (square root of estimated tau^2 value):      0
I^2 (total heterogeneity / total variability):   0.00%
H^2 (total variability / sampling variability):  1.00

Test for Heterogeneity: 
Q(df = 7) = 2.2869, p-val = 0.9423

Model Results:

estimate       se     zval     pval    ci.lb    ci.ub          
-11.7549   3.4211  -3.4360   0.0006 -18.4601  -5.0496      *** 

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