[R-meta] compare multiple "bayesmeta" estimates
Simon Harmel
@|m@h@rme| @end|ng |rom gm@||@com
Sun Dec 27 17:29:58 CET 2020
Thank you very much, Christian. I appreciate it. I know and highly
appreciate the fact that you've put so much effort into making bayesmeta
faster than the MCMC-based equivalents.
But, I really hope that one day we would be able to see still much faster
algorithms to enable applying Bayesian meta to large-scale research efforts.
Once again, thank you very much,
Simon
On Sun, Dec 27, 2020 at 6:00 AM Röver, Christian <
christian.roever using med.uni-goettingen.de> wrote:
> 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 Röver, Christian <
> > christian.roever using 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
> > > >
> > > >
>
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