Message-ID: <fcb5f406671d48368913066a64ae2b0c@uni-trier.de>
Date: 2022-09-18T15:42:44Z
From: Thölking, Theresa
Subject: [R-meta] mathematical equation confidence and prediction intervals 3- and 4-level models
In-Reply-To: <8f8bb4164e8e4a6a878753ae97a8a5d0@UM-MAIL3214.unimaas.nl>
Dear Wolfgang,
thanks for your explanation, that was very helpful.
Best,
Theresa
________________________________
Von: Viechtbauer, Wolfgang (NP) <wolfgang.viechtbauer at maastrichtuniversity.nl>
Gesendet: Sonntag, 18. September 2022 17:23:29
An: r-sig-meta-analysis at r-project.org
Cc: Th?lking, Theresa
Betreff: RE: mathematical equation confidence and prediction intervals 3- and 4-level models
Dear Theresa,
There isn't anything special about calculating the CI. It's just the pooled estimate +- the critical value (1.96 if test="z"; otherwise, the corresponding quantile from a t-distribution) times the standard error.
For the PI, a sensible thing to do (assuming you are talking about a model where 'random' is something like '~ study/estimate' or '~ author/study/estimate' or something along those lines) is to compute it in the same way as for a 'standard' random-effects model as described here:
https://www.metafor-project.org/doku.php/faq#for_random-effects_models_fitt
but using the sum of all variance components as 'tau^2' (essentially: sum(res$sigma2)).
I hope this is the level of detail you are looking for.
Best,
Wolfgang
>-----Original Message-----
>From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces at r-project.org] On
>Behalf Of Th?lking, Theresa
>Sent: Sunday, 18 September, 2022 17:02
>To: r-sig-meta-analysis at r-project.org
>Subject: [R-meta] mathematical equation confidence and prediction intervals 3-
>and 4-level models
>
>Hello everybody,
>
>does anybody know the mathematical equation of how prediction and confidence
>intervals are calculated in 3-level and 4-level meta-analytic models in R? Thanks
>in advance.
>
>Best,
>Theresa
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