[R-meta] Accounting for baseline differences in meta-analysis

[Gladys Barragan-Jason]

Dear Gerta,
Thanks for your response. I also realized that most of the time papers do
not report the pre-treatment and/or the pre-control values. Sometimes they
just say that the values are not different but do not report thoses, but
more often they do not measure it at all.  Is there any way to take this
into account?...I am not sure about how to deal with presence vs. absence
of such values in the meta-analysis or whether this just needs to be
discussed as a potential limitation.
Thanks a lot for your response.
Gladys

Le jeu. 28 janv. 2021 à 12:35, Dr. Gerta Rücker <
ruecker using imbi.uni-freiburg.de> a écrit :

> Dear Gladys,
>
> An obvious approach would be to take the post values (or, equivalently,
> the change scores) as an outcome, and the baseline values as a covariate in
> a metaregression model.
>
> Best,
>
> Gerta
> Am 28.01.2021 um 10:49 schrieb Gladys Barragan-Jason:
>
> Dear all,
> I would like to know how to take the baseline difference into account in
> meta-analysis of the impact of a treatment on experimental data in which
> the baseline of the control group is different from the baseline of the
> treatment.
> For now, I am using the post- means and SD of the control and the
> treatment group (and the rma.mv function) and also the pre-post values of
> the treatment group but I don't think this is correct and I am not sure how
> to proceed.
> Any advice?
> Thanks a lot in advance.
> Best regards,
> Gladys
>
> --
>
> ------------------------------------------
>
> Gladys Barragan-Jason, PhD.  Website
> <https://sites.google.com/view/gladysbarraganjason/home>
>
> Station d'Ecologie Théorique et Expérimentale (SETE)
>
> CNRS de Moulis
>
> [image: image.png][image: image.png]
>
>
>
>
> _______________________________________________
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>

-- 

------------------------------------------

Gladys Barragan-Jason, PhD.  Website
<https://sites.google.com/view/gladysbarraganjason/home>

Station d'Ecologie Théorique et Expérimentale (SETE)

CNRS de Moulis

[image: image.png][image: image.png]

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