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<p>Joao,</p>
<p>I can only find a very subtle difference in the results of the
Freeman-Tukey method between <b>meta</b> and <b>metafor</b>.
While <b>meta</b> uses subgroup-specific harmonic means to
back-transform results, <b>metafor</b> uses the harmonic mean of
all studies for both subgroups. Differences are only visible in
the third digit for prevalence estimates and confidence intervals.</p>
<p>Another point to mention is that differences in results of random
effects subgroup analyses (i) allowing for different estimates of
the between-study variance tau2 and (ii) assuming a common value
of tau2 have to be expected. It should be clear that subgroup
analyses assuming a common value for tau2 of 0.0218 produce
different results than two separate subgroup analyses using values
of 0.0109 and 0.0269, respectively.</p>
<p>Best wishes, Guido</p>
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