[R-meta] compare multiple "bayesmeta" estimates

Dear Simon,

yes, there is a way to investigate the difference of the two as well.
Asking for the difference between the two unknowns (the two mean
parameters) technically means asking for a *convolution* of their
probability distributions. From the "bayesmeta()" output we get the
probability density functions etc, and from these we can derive the
convolution. A method to compute the convolution is described here:

  C. Roever and T. Friede.
  Discrete approximation of a mixture distribution
  via restricted divergence.
  Journal of Computational and Graphical Statistics,
  26(1):217-222, 2017.
  https://doi.org/10.1080/10618600.2016.1276840

and R code is provided in the article's supplemental material.

I attached some R code to show the computations based on the "metafor"
example.

Cheers,

Christian



On Sat, 2020-12-26 at 13:49 -0600, Simon Harmel wrote:

Dear Christian,

Thank you very much. To be clear, you're suggesting a meta-analysis
of the subgroup meta-analyses, correct?

Well, in my case, I have way too many subgroups, so there will be
many pairwise comparisons. I wonder if there is a way to get the
large posterior samples from each subgroup' summary effect and
subtract it from the large posterior samples from another subgroup
summary effect etc.?

Perhaps, then we can see if the HDI of the posterior of difference
includes "0"?

Is this possible and/or reasonable given that my goal is to see if
one subgroup is "different" from another one or not?

Thank you,
Simon

On Sat, Dec 26, 2020 at 12:38 PM R?ver, Christian <
christian.roever at med.uni-goettingen.de> wrote:

Dear Simon,

you can essentially do an analogous analysis (in two stages) using
the
"bayesmeta" package. Doing the one-stage meta-regression approach
is
not (yet) possible with bayesmeta, but it should be possible via
"rjags" (of required).

For the two-stage approach, we then only need to use a normal
approximation for the results from the 1st-stage analyses and
proceed
from there.

I attached some example R code based on the quoted "metafor"
example.

Cheers,

Christian



On Sat, 2020-12-26 at 10:46 -0600, Simon Harmel wrote:

Hello All,

Using "bayesmeta" package, I want to compare multiple estimates

of

independent Meta-Analyses (i.e., Subgroups).

In metafor, I know we can do this: (

http://www.metafor-project.org/doku.php/tips:comp_two_independent_estimates

)

But I have fit my models in the "bayesmeta" package, so I was
wondering how to compare across my "bayesmeta" models?

Thanks,
Simon