Dear Daidai, You sent your email when I just went on holidays. You have been using the wrong value for argument 'n' in backtransf(). R package meta uses the harmonic mean of the sample sizes in the back-transformation of Freeman-Tukey double arcsine transformed proportions: backtransf(test_meta$TE.common, sm = "PFT", n = 1 / mean(1 / test_meta$n)) backtransf(test_meta$TE.random, sm = "PFT", n = 1 / mean(1 / test_meta$n)) The use of the harmonic mean goes back to the publication by Miller (1978) - see help page of metaprop(). Best wishes, Guido
[R-meta] Output value reported from metaprop function
1 message · Guido Schwarzer