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altmeta (version 4.1)

metapb: Detecting and Quantifying Publication Bias/Small-Study Effects

Description

Performs the regression test and calculates skewness for detecting and quantifying publication bias/small-study effects.

Usage

metapb(y, s2, data, model = "RE", n.resam = 1000)

Value

This function returns a list containing measures of publication bias, their 95% confidence intervals, and p-values. Specifically, the components include:

n

the number of studies in the meta-analysis.

p.Q

the p-value of the \(Q\)-test for heterogeneity.

I2

the \(I^2\) statistic for quantifying heterogeneity.

tau2

the DerSimonian--Laird estimate of the between-study variance.

model

the model setting ("FE" or "RE").

std.dev

the standardized deviates of the studies.

reg.int

the estimate of the regression intercept for quantifying publication bias.

reg.int.ci

the 95% CI of the regression intercept.

reg.int.ci.resam

the 95% CI of the regression intercept based on the resampling method.

reg.pval

the p-value of the regression intercept.

reg.pval

the p-value of the regression intercept based on the resampling method.

skewness

the estimate of the skewness for quantifying publication bias.

skewness.ci

the 95% CI of the skewness.

skewness.ci.resam

the 95% CI of the skewness based on the resampling method.

skewness.pval

the p-value of the skewness.

skewness.pval.resam

the p-value of the skewness based on the resampling method.

combined.pval

the p-value of the combined test that incorporates the regression intercept and the skewness.

combined.pval.resam

the p-value of the combined test that incorporates the regression intercept and the skewness based on the resampling method.

Arguments

y

a numeric vector specifying the observed effect sizes in the collected studies; they are assumed to be normally distributed.

s2

a numeric vector specifying the within-study variances.

data

an optional data frame containing the meta-analysis dataset. If data is specified, the previous arguments, y and s2, should be specified as their corresponding column names in data.

model

a characher string specifying the fixed-effect ("FE") or random-effects ("RE", the default) model. If not specified, this function uses the \(Q\) statistic to test for heterogeneity: if the p-value is smaller than 0.05, model is set to "RE"; otherwise, model = "FE".

n.resam

a positive integer specifying the number of resampling iterations.

Details

This function derives the measures of publication bias introduced in Lin and Chu (2018).

References

Egger M, Davey Smith G, Schneider M, Minder C (1997). "Bias in meta-analysis detected by a simple, graphical test." BMJ, 315(7109), 629--634. <tools:::Rd_expr_doi("10.1136/bmj.315.7109.629")>

Lin L, Chu H (2018). "Quantifying publication bias in meta-analysis." Biometrics, 74(3), 785--794. <tools:::Rd_expr_doi("10.1111/biom.12817")>

Examples

Run this code
data("dat.slf")
set.seed(1234)
metapb(y, s2, dat.slf)

data("dat.ha")
set.seed(1234)
metapb(y, s2, dat.ha)

data("dat.lcj")
set.seed(1234)
metapb(y, s2, dat.lcj)

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