[R-meta] rma.mv-When a higher level can't be modeled because of one row

[Farzad Keyhan]

Thanks Wolfgang.

Yes, this is just the data structure. Focusing on the "making
[measure] nested within study" part of your suggestion, you mean in
row # 3, I recode the "measure" value of 1 to 2, or even delete row #
3 altogether, or "~1 | measure/study/outcome" by default will take
care of making "measure" nested in study?

Thank you,
Fred

On Mon, Nov 8, 2021 at 4:13 AM Viechtbauer, Wolfgang (SP)
<wolfgang.viechtbauer using maastrichtuniversity.nl> wrote:
>
> Dear Fred,
>
> I would consider using measure as a fixed effect or making it nested within study (or within outcome). But none of this might really be appropriate for a dataset this small (but I assume this was just constructed for illustrating your question).
>
> Best,
> Wolfgang
>
> >-----Original Message-----
> >From: Farzad Keyhan [mailto:f.keyhaniha using gmail.com]
> >Sent: Friday, 05 November, 2021 2:59
> >To: R meta
> >Cc: Viechtbauer, Wolfgang (SP)
> >Subject: Re: rma.mv-When a higher level can't be modeled because of one row
> >
> >For clarity, by a solution, I mean how can I account for the
> >heterogeneity in true effects attributable to "measure", while
> >"measure" is neither a perfect candidate for being the nestor of
> >study:
> >
> >random = ~1 | measure/study/outcome
> >
> >nor a perfect candidate for being crossed with study:
> >
> >random = list(~1 | study/outcome, ~1|measure)
> >
> >Thank you,
> >Fred
> >
> >On Thu, Nov 4, 2021 at 2:26 PM Farzad Keyhan <f.keyhaniha using gmail.com> wrote:
> >>
> >> Dear Experts,
> >>
> >> In my toy data below, if in row # 3, "measure" was 2 (instead of 1),
> >> then, I could take "measure" as a level higher than study:
> >>
> >> random = ~1 | measure/study/outcome
> >>
> >> But right now, because in study 2 (rows # 3 and 4) "measure" can vary,
> >> "measure" can't be considered a level higher than study.
> >>
> >> On the other hand, because "measure" varies only in one study, I can't
> >> take "measure" as a crossed random-effect either.
> >>
> >> I was wondering what solutions the expert list members might have for
> >> this situation?
> >>
> >> Thanks,
> >> Fred
> >>
> >>    measure       row   study   outcome
> >>    1             1     1       1
> >>    1             2     1       2
> >> #  1             3     2       1 <--- measure on this row
> >>    2             4     2       1
> >>    1             5     3       1
> >>    1             6     3       2