funnel {meta} | R Documentation |
Draw a funnel or radial plot to assess funnel plot asymmetry in the active graphics window.
funnel(x, y, xlim=NULL, ylim=NULL, xlab=NULL, ylab=NULL, comb.fixed=FALSE, axes=TRUE, pch=1, text=NULL, cex=1, col=NULL, log="", yaxis="se", sm=NULL, level=NULL, ...) radial(x, y, xlim=NULL, ylim=NULL, xlab="Inverse of standard error", ylab="Standardised treatment effect (z-score)", comb.fixed=TRUE, axes=TRUE, pch=1, text=NULL, cex=1, col=NULL, level=NULL, ...)
x |
An object of class meta , or estimated treatment
effect in individual studies. |
y |
Standard error of estimated treatment effect (mandatory if
x not of class meta ). |
xlim |
The x limits (min,max) of the plot. |
ylim |
The y limits (min,max) of the plot. |
xlab |
A label for the x axis. |
ylab |
A label for the y axis. |
comb.fixed |
A logical indicating whether the pooled fixed effect estimate should be plotted. |
axes |
A logical indicating whether axes should be drawn on the plot. |
pch |
The plotting symbol used for individual studies. |
text |
A character vector specifying the text to be used instead of plotting symbol. |
cex |
The magnification to be used for plotting symbol. |
col |
A vector with colour of plotting symbols. |
log |
A character string which contains "x" if the x axis
is to be logarithmic, "y" if the y axis is to be logarithmic
and "xy" or "yx" if both axes are to be logarithmic
(applies only to function funnel ). |
yaxis |
A character string indicating which type of weights are
to be used. Either "se" , "invvar" , "invse" , or "size"
(applies only to function funnel ). |
sm |
A character string indicating underlying summary measure,
e.g., "RD" , "RR" , "OR" , "AS" , "MD" ,
"SMD" (applies only to function funnel ). |
level |
The confidence level utilised in the plot. For the funnel
plot, confidence limits are not drawn if yaxis="size" . |
... |
Graphical parameters as in par may also be
passed as arguments. |
A funnel plot or radial plot, also called Galbraith plot, is drawn in
the active graphics window. If comb.fixed
is TRUE, the pooled
estimate of the fixed effect model is plotted. If level
is not
NULL, the corresponding confidence limits are drawn.
In the funnel plot, if yaxis
is "se"
, the standard error
of the treatment estimates is plotted on the y axis which is likely to
be the best choice (Sterne & Egger, 2001). Other possible choices for
yaxis
are "invvar"
(inverse of the variance),
"invse"
(inverse of the standard error), and "size"
(study size).
Guido Schwarzer sc@imbi.uni-freiburg.de
Galbraith RF (1988a), Graphical display of estimates having differing standard errors. Technometrics, 30, 271–281.
Galbraith RF (1988b), A note on graphical presentation of estimated odds ratios from several clinical trials. Statistics in Medicine, 7, 889–894.
Light RJ & Pillemer DB (1984), Summing Up. The Science of Reviewing Research. Cambridge: Harvard University Press.
Sterne JAC & Egger M (2001), Funnel plots for detecting bias in meta-analysis: Guidelines on choice of axis. Journal of Clinical Epidemiology, 54, 1046–1055.
data(Olkin95) meta1 <- metabin(event.e, n.e, event.c, n.c, data=Olkin95, subset=c(41,47,51,59), sm="RR", meth="I") oldpar <- par(mfrow=c(2, 2)) funnel(meta1) ## ## Same result as code above: ## funnel(meta1$TE, meta1$seTE, sm="RR") funnel(meta1, comb.fixed=TRUE, level=0.95) radial(meta1, level=0.95) par(oldpar)