[R-meta] converting effect sizes from RR to lnRR without original data

[Viechtbauer, Wolfgang (SP)]

Dear Diego,

If I need to convert an RR to lnRR, I just take the log. I don't know what that equation is supposed to do. It might help if you would tell you where you got it from.

Best,
Wolfgang

>-----Original Message-----
>From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces using r-project.org] On
>Behalf Of Diego Grados Bedoya
>Sent: Wednesday, 28 April, 2021 10:52
>To: R meta
>Subject: [R-meta] converting effect sizes from RR to lnRR without original data
>
>Dear all,
>
>I would like to convert an effect size from RR to lnRR. I do not have
>access to the original data. I just have the effect size (RR), standard
>error (SE) and the number of comparisons (N). I read that a direct log
>transformation of an RR can lead to an overestimation of the effect size,
>thus the authors proposed a correction for the log transformation as
>
>lnRR = ln(RR) - NSE2 x (2 RR2) - 1
>
>However, the formula is not fully described and there is not no further
>reference. I was trying to make sense of it but can not get good results. I
>wonder if you have some references or thoughts about it?
>
>Thank you in advance,
>
>Greetings,
>
>Diego