Bernd,
Thanks. I believe this will do what I need, but do you know how I can set up my meta object so that the meta is performed on each subgroup individually? I can get the overall meta of all 6 observations, or I can get a separate meta of each subgroup using the subset command, but I can't get subgroup A, subgroup B, and subgroup C all into the same object. In order to use the plot feature it appears I need a byvar, so I think I'll need them all in the same object.

subgroup    study    beta    se
subgroupA    site1    -0.35    0.12
subgroupA    site2    -0.34   
 0.1
subgroupB    site1    -0.28    0.06
subgroupB    site2    -0.29    0.07
subgroupC    site1    0.34    0.03
subgroupC    site2    0.36    0.04
Generic inverse variance meta-analysismetagen(beta, se, studlab=study, sm="OR")

Thanks,
Steve

--- On Tue, 3/10/09, Weiss, Bernd <bernd.weiss@uni-koeln.de> wrote:
From: Weiss, Bernd <bernd.weiss@uni-koeln.de>
Subject: Re: [R] perform subgroup meta-analysis and create forest plot displaying subgroups
To: slubitz1@yahoo.com, r-help@r-project.org
Date: Tuesday, March 10, 2009, 2:31 AM

Steven Lubitz schrieb:
> Hello, I'm using the rmeta package to perform a meta analysis
 using
> summary statistics rather than raw data, and would like to analyze
> the effects in three different subgroups of my data. Furthermore, I'd
> like to plot this on one forest plot, with corresponding summary
> weighted averages of the effects displayed beneath each subgroup.
> 
> I am able to generate the subgroup analyses by simply performing
 3
> separate meta-analyses with the desired subset of data. However, I
> can't manage to plot everything on the same forest plot.

Maybe I'm wrong but the 'forest'-function (package 'meta',
<http://cran.at.r-project.org/web/packages/meta/meta.pdf>) should be able
to do what you want. I guess you could be interested in the 'byvar'
argument.

Bernd



      
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