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

[Viechtbauer, Wolfgang (SP)]

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