Hi Dr. Viechtbauer, The code provided in the metafor projects website for subgroup includes fitting a random effects model on the entire dataset and fitting a random effects model within subgroups. When I exactly follow this code, my estimates and confidence intervals for estimate within each subgroup matches with what I get in STATA so it seems to be the correct estimate (and CI). However, I don't want to present an overall effect and I want to present only the effect within each subgroup. In my second attempt, I did not run a random effects model within the entire dataset and only ran the models within each subgroup. I generated a variable corresponding to the estimate(risk ratio) and standard error which I plugged in the forest() function (i.e. forest(rr, se, .....). When I run this code, the estimate I get for each subgroup is slightly different than the estimate I get for each subgroup in comparison to when I also included the random effects model for the overall effect. (i.e. my first attempt). Is this the right approach? I was not clear when you said passing the estimates and sampling variances to the forest() function. I created a variable corresponding to the estimate and standard error and plugged those in the forest() function. I am not sure if this is the right approach. Thanks,
John On 8 December 2015 at 03:47, Viechtbauer Wolfgang (STAT) < wolfgang.viechtba...@maastrichtuniversity.nl> wrote: > Hi John, > > Please keep r-help copied on the reply. > > What's the 'previous model'? How do you get estimates within subgroups > that 'includes the overall effect'? I really cannot follow you here. > > Best, > Wolfgang > > -- > Wolfgang Viechtbauer, Ph.D., Statistician | Department of Psychiatry and > Neuropsychology | Maastricht University | P.O. Box 616 (VIJV1) | 6200 MD > Maastricht, The Netherlands | +31 (43) 388-4170 | http://www.wvbauer.com > > > -----Original Message----- > > From: John Peterson [mailto:john.peterson....@gmail.com] > > Sent: Monday, December 07, 2015 22:14 > > To: Viechtbauer Wolfgang (STAT) > > Subject: Re: [R] metafor package > > > > Hi Dr. Viechtbauer, > > Thank you very much for your reply. I tried your advice and was able to > > make a forest plot with only the estimates for each subgroup.For the > > estiamte for each subgroup, similar to the previous model, I random > > effects model within each subgroup. However, I now find the result for > > the estiamte within subgroup to be different thant the result for the > > previous model. I have tried analyzing this in STATA and I get the same > > result as the model which includes the overall effect. Any advice on what > > may be wrong here? Thanks greatly, > > John > > > > On 7 December 2015 at 04:02, Viechtbauer Wolfgang (STAT) > > <wolfgang.viechtba...@maastrichtuniversity.nl> wrote: > > The code you posted is totally mangled up, but it's just what can be > > found here: > > > > http://www.metafor-project.org/doku.php/plots:forest_plot_with_subgroups > > > > If you don't want an overall estimate, just pass the estimates and > > corresponding sampling variances to the forest() function (and not the > > model object). Use the 'rows' argument to specify where the estimates > > will be placed and adjust 'ylim' so give you enough space to leave gaps > > for headings and the subgroup estimates. Then fit models within the > > subgroups (the 'subset' argument is useful here) and use addpoly() to add > > the subgroup estimates in the appropriate rows. With text(), you can add > > headings as needed. > > > > If you use weights() on each subgroup model object, you can get the > > subgroup weights (that add up to 100% within each subgroup). It's > > probably easiest to just add those values with text() in an appropriate > > place to the plot. > > > > Best, > > Wolfgang > > > > -- > > Wolfgang Viechtbauer, Ph.D., Statistician | Department of Psychiatry and > > Neuropsychology | Maastricht University | P.O. Box 616 (VIJV1) | 6200 MD > > Maastricht, The Netherlands | +31 (43) 388-4170 | http://www.wvbauer.com > > > > > -----Original Message----- > > > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of John > > > Peterson > > > Sent: Monday, December 07, 2015 01:39 > > > To: r-help@r-project.org > > > Subject: [R] metafor package > > > > > > Hi Everyone, > > > > > > I am conducting a meta-analysis using the metafor package. I am > > > interested > > > in obtaining an estimate by subgroup only without showing an overall > > > effect. This is directly from the metafor website. How would i modify > > > this > > > code to only show subgroup effects? Further, I want to show weights by > > > subgroup. The option showweights=TRUE does not display weights by > > > subgroup > > > but by the weight of each study in comparison to all studies (and not > > the > > > subgroup). You help would be appreciated. > > [snip garbled code] > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.