R: Sensitivity Analysis for Outcome Reporting Bias (ORB)
orbbound
R Documentation
Sensitivity Analysis for Outcome Reporting Bias (ORB)
Description
Implementation of the method by Copas & Jackson (2004) to evaluate
outcome reporting bias in meta-analysis. An upper bound for outcome
reporting bias is estimated for a given number of studies suspected
with outcome reporting bias.
Number of studies with suspected outcome reporting bias.
tau
Square-root of between-study variance
tau-squared.
left
A logical indicating whether the cause of any selection
bias is due to missing studies on the left or right of the funnel
plot: left hand side if left=TRUE, right hand side if
left=FALSE. If not set, the linear regression test for
funnel plot asymmetry (i.e., function metabias(...,
meth="linreg")) is used to determine whether studies are missing
on the left or right hand side.
backtransf
A logical indicating whether results should be
back transformed in printouts and plots. If backtransf=TRUE
(default), results for sm="OR" are printed as odds ratios
rather than log odds ratio, for example.
Details
This function provides the method by Copas and Jackson (2004) to
estimate an upper bound for bias for a given number of studies with
suspected outcome reporting bias.
Based on the upper bound of outcome reporting bias, treatment
estimates and confidence limits adjusted for bias are calculated.
For comparison, the original meta-analysis is always considered in
the sensitivity analysis (i.e. value 0 is always added to
k.suspect).
Value
An object of class c("orbbound") with corresponding
print and forest function. The object is a list
containing the following components:
k.suspect, tau
As defined above.
maxbias
Maximum bias for given values of k.suspect.
fixed
Adjusted treatment estimates and corresponding
quantities for fixed effect model (a list with elements TE, seTE,
lower, upper, z, p, level, df).
random
Adjusted treatment estimates and corresponding
quantities for random effects model (a list with elements TE,
seTE, lower, upper, z, p, level, df).
left
Whether selection bias expected on left or right
x
Meta-analysis object (i.e. argument x from function call).
call
Function call.
version
Version of R package metasens used to create object.