[R-meta] multivariate fixed-effect meta-analysis

[Viechtbauer, Wolfgang (SP)]

With method="FE", 'random' is also ignored. You will see in the output that it says "Variance Components: none".

If 'cov_mat' captures the sampling error covariances, then this could be argued to be a fixed-effects version of a multivariate model.

Best,
Wolfgang

>-----Original Message-----
>From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces using r-project.org] On
>Behalf Of Filippo Gambarota
>Sent: Tuesday, 23 November, 2021 20:07
>To: R meta
>Subject: [R-meta] multivariate fixed-effect meta-analysis
>
>Hi!
>I'm performing a multivariate meta-analysis with metafor, however I'm
>not sure how to obtain the fixed-effect version. Given that I have not
>enough data I'm not interested in estimating tau for each outcome and
>the correlation among outcomes but only taking into account the
>sampling error dependence. I'm using this function:
>```
>rma.mv(
>    yi = eff_size,
>    V = cov_mat,
>    mods = ~ 0 + outcome,
>    struct = "UN",
>    random = ~ outcome|paper_id,
>    method = "FE",
>    data = data)
>```
>Of course, the struct argument is no more relevant (as the warning
>message said) but I'm wondering if the result is what I'm looking for
>because from the rma.mv documentation the method = "FE" is not
>mentioned combined with a multivariate parametrization.
>Thank you!
>
>--
>Filippo Gambarota
>PhD Student - University of Padova
>Department of Developmental and Social Psychology
>Website: filippogambarota.netlify.app
>Research Group: Colab   Psicostat