Jokel Meyer
2011-Jul-18 16:44 UTC
[R] Extract confidence intervals from rma object (metafor package)
Dear R-experts! I am working on some meta-analysis using the metafor package. I would like to extract values of the confidence intervals of the effect sizes of the single studies from an rma object. Those values are printed out when plotting a forest plot using the forest function on the rma object, however I was not able to locate them. Many thanks for your help! Jokel [[alternative HTML version deleted]]
Viechtbauer Wolfgang (STAT)
2011-Jul-18 17:40 UTC
[R] Extract confidence intervals from rma object (metafor package)
Dear Jokel,
Right now, none of the functions return that information. But it's easy to
calculate those CIs by hand (simply take yi +- 1.96 sqrt(vi) and apply, if
needed, some appropriate transformation). For example:
data(dat.bcg)
dat <- escalc(measure="RR", ai=tpos, bi=tneg, ci=cpos, di=cneg,
data=dat.bcg, append=TRUE)
exp(dat$yi - 1.96*sqrt(dat$vi))
exp(dat$yi + 1.96*sqrt(dat$vi))
gives you approximate 95% CIs for the RRs. The forest functions essentially do
nothing different.
I hope this helps!
Best,
--
Wolfgang Viechtbauer
Department of Psychiatry and Neuropsychology
School for Mental Health and Neuroscience
Maastricht University, P.O. Box 616
6200 MD Maastricht, The Netherlands
Tel: +31 (43) 368-5248
Fax: +31 (43) 368-8689
Web: http://www.wvbauer.com
________________________________________
From: r-help-bounces at r-project.org [r-help-bounces at r-project.org] On
Behalf Of Jokel Meyer [jokel.meyer at googlemail.com]
Sent: Monday, July 18, 2011 6:44 PM
To: r-help at r-project.org
Subject: [R] Extract confidence intervals from rma object (metafor package)
Dear R-experts!
I am working on some meta-analysis using the metafor package. I would like
to extract values of the confidence intervals of the effect sizes of the
single studies from an rma object. Those values are printed out when
plotting a forest plot using the forest function on the rma object, however
I was not able to locate them.
Many thanks for your help!
Jokel
[[alternative HTML version deleted]]
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