[R-meta] Fwd: SV: Re:: Question: Metafor R package - rma and rma.mv function

Dear Simona,

Did you see my reply?

https://stat.ethz.ch/pipermail/r-sig-meta-analysis/2018-July/000949.html

Best,
Wolfgang

-----Original Message-----
From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces at r-project.org] On Behalf Of Simona Frederiksen
Sent: Wednesday, 25 July, 2018 22:45
To: r-sig-meta-analysis at r-project.org
Subject: [R-meta] Fwd: SV: Re:: Question: Metafor R package - rma and rma.mv function

Dear Michael,

Thank you for your fast reply. It is very appreciated. I should have changed it to plain text now.

Maybe I?am not quite aware of how this is computed. The model that I am fitting is it as follows: yi = mean + uj[i] + ei for the i?th comparison and the j?th study when using the rma.mv function? And how is the weights applied to it or calculated?

I tried to use the profile.rma.mv() function and I got one maxima. Can I then assume that it is converged?

Best wishes,

Simona
________________________________
Fra: Michael Dewey <lists at dewey.myzen.co.uk<mailto:lists at dewey.myzen.co.uk>>
Sendt: Wednesday, July 25, 2018 3:06:06 PM
Til: Simona Frederiksen; r-sig-meta-analysis at r-project.org<mailto:r-sig-meta-analysis at r-project.org>
Emne: Re:: [R-meta] Question: Metafor R package - rma and rma.mv function

Simona Frederiksen <simona.frederiksen at hotmail.com<mailto:simona.frederiksen at hotmail.com>> wrote :

Dear Simona

Given the calculated variances (vi) the weights seem quite OK to me.

Would the question underlying the convergence issue be better answered by using profile.rma.mv()?

Please set your mailer to post in plain text not HTML as your post got mangled which made running your example rather tricky.

Michael.

Hi,

I have some question sthat I would like to get posted regarding the metafor R
package and the rma and rma.mv function. It goes like this:

Hi,

I am at the moment working in the R package 'metafor' in order to perform a
meta-analysis which I carry out in collaboration with the Danish Headache
Center. I just figured that I have to use the rma.mv function since I have
several effect sizes per study (for two studies).

I have following questions that I hope you can help me answer:

  1.  When I calculate the weights for each study, the studies that have more
effect sizes receive a really high weight compared to the other studies with
just one effect size. So it seems that these studies primarily are used to
calculate the overall effect size even though N seems to be quite small?

  1.  How can I see convergence when I use the rma.mv function? When using the
rma function, it turns up when adding verbose = T. And if it does not converge,
what would be ideal to do?

Here is an example:
library("metafor")
study_id