[R-meta] nesting an inner | outer formula

[Viechtbauer, Wolfgang (NP)]

Dear Ross,

my proc mixed knowledge is a bit rusty, but unless I am confused, your proc mixed statement specifies a random intercept for StudyID and an UN structure for Informant within StudyID allowing for different variances/covariances for the different levels of TreatmentGroup.

> random StudyID;
> random Informant / subject=StudyID group=TreatmentGroup type=un;
> parms  1  1 1 1  1 1 1  1 1 1  1 1 1  1 / hold=14;

I don't think this quite matches up with your description:

> I would like for the different levels of Informant to be correlated within
> TreatmentGroup within StudyID, and I would like the different levels of
> TreatmentGroup to be correlated within StudyID too.

For example, there is nothing in your proc mixed statement that allows for "TreatmentGroup to be correlated within StudyID". Also, the second random statement allows for Informant to be correlated within StudyID, but *not* "within TreatmentGroup within StudyID".

So before I attempt to recreate the same structure, it would need to be clear exactly what kind of structure you really want.

Best,
Wolfgang

> -----Original Message-----
> From: Ross Neville <ross.neville using ucd.ie>
> Sent: Thursday, February 13, 2025 18:28
> To: Viechtbauer, Wolfgang (NP) <wolfgang.viechtbauer using maastrichtuniversity.nl>;
> r-sig-meta-analysis using r-project.org
> Subject: nesting an inner | outer formula
>
> Hi Wolfgang
>
> I hope this email finds you well
>
> I was wondering if you could tell me whether the following list of random
> effects can be updated to make the the inner | outer formula conditional.
>
> random = list (~ 1 | StudyID, ~ Informant | TreatmentGroup)
>
> I would like for the different levels of Informant to be correlated within
> TreatmentGroup within StudyID, and I would like the different levels of
> TreatmentGroup to be correlated within StudyID too.
>
> In SAS Proc Mixed, I've managed to run this model and I want to replicate it in
> metafor rma.mv.
>
> random StudyID;
> random Informant/subject=StudyID, group=TreatmentGroup type=un;
> parms  1  1 1 1  1 1 1  1 1 1  1 1 1  1/hold=14;
>
> Any help you can provide to let me know if this is possible in http://rma.mv
> would be much appreciated.
>
> Regards
> Ross
>
> --
> Dr Ross D. Neville, PhD, ProfCert University Teaching and Learning
> Head of Subject - Sport Management
> School of Public Health, Physiotherapy and Sport Science
> University College Dublin (UCD)
> Room G6 - Woodview House
> Belfield, Dublin 4
> mailto:ross.neville using ucd.ie
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