[R-meta] Bivariate generalized linear mixed model with {metafor}

[Viechtbauer, Wolfgang (SP)]

Which correlation are you interested in? And are you even interested in the correlation? If not, it doesn't really matter then.

Best,
Wolfgang

>-----Original Message-----
>From: Arthur Albuquerque [mailto:arthurcsirio using gmail.com]
>Sent: Wednesday, 09 March, 2022 23:51
>To: r-sig-meta-analysis using r-project.org; Viechtbauer, Wolfgang (SP)
>Subject: RE: [R-meta] Bivariate generalized linear mixed model with {metafor}
>
>Wow, crazy numerical coincidence then.
>
>I’ve been wondering about applying Reference [1] model (= your Model 6) in future
>projects. Can you see any practical reason to apply the (group | study) syntax
>instead of (control+treat-1|study)?
>
>Best,
>
>Arthur M. Albuquerque
>
>Medical student
>Universidade Federal do Rio de Janeiro, Brazil
>
>On Mar 9, 2022, 7:47 PM -0300, Viechtbauer, Wolfgang (SP)
><wolfgang.viechtbauer using maastrichtuniversity.nl>, wrote:
>
>Different parameterizations of the same model.
>
>Also, the correlations seems like they just flipped signs, but they are really
>different things and I suspect it's just coincidence that they happen to be so
>close in absolute value.
>
>With (group | study), you have a random intercept (for the control group logit
>risk) and a random slope for the group/treatment effect (for the log odds ratio).
>
>With (control+treat-1|study), you have random effects for the control and
>treatment group logit risks. This is the same as (0 + group | study).
>
>So really different things are being correlated here. But in the end, it's the
>same model, parameterized in different ways.
>
>Best,
>Wolfgang