trimfill {meta} | R Documentation |
Trim and fill method for estimating and adjusting for the number and outcomes of missing studies in a meta-analysis.
trimfill(x, seTE, ...)
x |
An object of class meta , or estimated treatment
effect in individual studies. |
seTE |
Standard error of estimated treatment effect (mandatory if
x not of class meta ). |
... |
Additional arguments. |
The trim and fill method can be used for estimating and adjusting for the number and outcomes of missing studies in a meta-analysis. The method relies on scrutiny of one side of a funnel plot for asymmetry assumed due to publication bias.
An object of class c("metagen", "meta", "trimfill")
. The object is a
list containing the following components:
studlab, sm, left, ma.fixed, type |
|
n.iter.max, level, level.comb, |
As defined above. |
comb.fixed, comb.random |
|
TE, seTE |
Estimated treatment effect and standard error of individual studies. |
w.fixed, w.random |
Weight of individual studies (in fixed and random effects model). |
TE.fixed, seTE.fixed |
Estimated overall treatment effect and standard error (fixed effect model). |
TE.random, seTE.random |
Estimated overall treatment effect and standard error (random effects model). |
k |
Number of studies combined in meta-analysis. |
Q |
Heterogeneity statistic Q. |
tau |
Square-root of between-study variance (moment estimator of DerSimonian-Laird). |
method |
Pooling method: "Inverse" . |
call |
Function call. |
n.iter |
Actual number of iterations to estimate number of missing studies. |
trimfill |
A logical vector indicating studies that have been added by trim and fill method. |
k0 |
Number of studies added by trim and fill. |
Guido Schwarzer sc@imbi.uni-freiburg.de
Duval S & Tweedie R (2000), A nonparametric "Trim and Fill" method of accounting for publication bias in meta-analysis. Journal of the American Statistical Association, 95, 89–98.
Duval S & Tweedie R (2000), Trim and Fill: A simple funnel-plot-based method of testing and adjusting for publication bias in meta-analysis. Biometrics, 56, 455–463.
metagen
, metabias
, trimfill.meta
, funnel
data(Fleiss93) meta1 <- metabin(event.e, n.e, event.c, n.c, data=Fleiss93, sm="OR") tf1 <- trimfill(meta1) summary(tf1) funnel(tf1, pch=ifelse(tf1$trimfill, 1, 16), level=0.95, comb.fixed=TRUE) trimfill(meta1$TE, meta1$seTE, sm=meta1$sm)