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

[Farzad Keyhan]

The actual data has 500 rows. That is just the structure of the data
that I showed. That is why I want to make sure if it is reasonable to
ignore 499 rows that agree with "measure/study" and just base my
random effect specification on one row that suggests "study/measure".

In other words, I want to make sure my random-effects seem a bit more
in line with the generality of my data rather than an exception that
has occurred in just one row.

Is there a consequence if I switch from "measure/study" to
"study/measure" given this situation?

On Mon, Nov 8, 2021 at 10:00 AM Viechtbauer, Wolfgang (SP)
<wolfgang.viechtbauer using maastrichtuniversity.nl> wrote:
>
> Like I said before, if this is really all the data, then I wouldn't do any of that, because this will be a way too complex model for so little data.
>
> >-----Original Message-----
> >From: Farzad Keyhan [mailto:f.keyhaniha using gmail.com]
> >Sent: Monday, 08 November, 2021 16:51
> >To: Viechtbauer, Wolfgang (SP)
> >Cc: R meta
> >Subject: Re: rma.mv-When a higher level can't be modeled because of one row
> >
> >Sure, so, I shouldn't worry that all rows but one suggest
> >"measure/study" and only because of that one exceptional row, do: "~ 1
> >| study/measure/outcome" or "~ 1 | study/outcome/measure"?
> >
> >Fred
> >
> >On Mon, Nov 8, 2021 at 9:39 AM Viechtbauer, Wolfgang (SP)
> ><wolfgang.viechtbauer using maastrichtuniversity.nl> wrote:
> >>
> >> No, I meant using "~ 1 | study/measure/outcome" or "~ 1 |
> >study/outcome/measure".
> >>
> >> Best,
> >> Wolfgang
> >>
> >> >-----Original Message-----
> >> >From: Farzad Keyhan [mailto:f.keyhaniha using gmail.com]
> >> >Sent: Monday, 08 November, 2021 16:22
> >> >To: Viechtbauer, Wolfgang (SP)
> >> >Cc: R meta
> >> >Subject: Re: rma.mv-When a higher level can't be modeled because of one row
> >> >
> >> >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