-----Original Message-----
From: ne gic [mailto:negic4 at gmail.com]
Sent: Wednesday, 10 June, 2020 13:13
To: Viechtbauer, Wolfgang (SP)
Cc: r-sig-meta-analysis at r-project.org
Subject: Re: [R-meta] Difference in Proportions Meta-Analysis
Dear Wolfgang,
I have taken time to read the entire?escalc documentation
(https://wviechtb.github.io/metafor/reference/escalc.html ) and I am sorry
to say I don't understand how I can do that in a single step with
escalc(measure="OR", ...) as you previously mentioned. I would like to do
this correctly following your suggestion so as to minimize any errors as I
redo steps that can be done in fewer steps.
For each of my two groups I have proportion and standard error. Could you
kindly show me how I can do this using one of the available datasets please?
Sincerely,
nelly
On Mon, Jun 8, 2020 at 6:48 PM Viechtbauer, Wolfgang (SP)
<wolfgang.viechtbauer at maastrichtuniversity.nl> wrote:
No, this is not correct. You should not apply the logit-transformation to
the difference and the SE is not correct either. You should apply the logit-
transformation to the two proportions individually, compute the correct SE
of the logit-transformed proportions, take the difference between the two
logit-transformed proportions, and then you can use the equation to get the
SE of this difference. But all of this can just be done in a single step
with escalc(measure="OR", ...). As I mentioned, the difference between two
logit-transformed proportions is the log odds ratio.
Best,
Wolfgang