meta (version 4.9-6)

metacum: Cumulative meta-analysis

Description

Performs a cumulative meta-analysis.

Usage

metacum(x, pooled, sortvar)

Arguments

x

An object of class meta.

pooled

A character string indicating whether a fixed effect or random effects model is used for pooling. Either missing (see Details), "fixed", or "random", can be abbreviated.

sortvar

An optional vector used to sort the individual studies (must be of same length as x$TE).

Value

An object of class c("metacum", "meta") with corresponding print, and forest functions. The object is a list containing the following components:

TE, seTE

Estimated treatment effect and standard error of pooled estimate in cumulative meta-analyses.

lower, upper

Lower and upper confidence interval limits.

studlab

Study label describing addition of studies.

p.value

P-value for test of overall effect.

w

Sum of weights from fixed effect or random effects model.

I2

Heterogeneity statistic I2.

Rb

Heterogeneity statistic Rb.

tau

Square-root of between-study variance.

df.hakn

Degrees of freedom for test of treatment effect for Hartung-Knapp method (only if hakn = TRUE).

sm

Summary measure.

method

Method used for pooling.

k

Number of studies combined in meta-analysis.

pooled

As defined above.

comb.fixed

A logical indicating whether analysis is based on fixed effect model.

comb.random

A logical indicating whether analysis is based on random effects model.

TE.fixed, seTE.fixed

Value is NA.

TE.random, seTE.random

Value is NA.

Q

Value is NA.

level.comb

The level used to calculate confidence intervals for pooled estimates.

hakn

A logical indicating whether the method by Hartung and Knapp is used to adjust test statistics and confidence intervals.

method.tau

A character string indicating which method is used to estimate the between-study variance \(\tau^2\).

tau.preset

Prespecified value for the square-root of the between-study variance \(\tau^2\).

TE.tau

Overall treatment effect used to estimate the between-study variance \(\tau^2\).

n.harmonic.mean

Harmonic mean of number of observations (for back transformation of Freeman-Tukey Double arcsine transformation).

version

Version of R package meta used to create object.

Details

A cumulative meta-analysis is performed. Studies are included sequentially as defined by sortvar.

Information from object x is utilised if argument pooled is missing. A fixed effect model is assumed (pooled = "fixed") if argument x$comb.fixed is TRUE; a random effects model is assumed (pooled = "random") if argument x$comb.random is TRUE and x$comb.fixed is FALSE.

References

Cooper H & Hedges LV (1994): The Handbook of Research Synthesis. Newbury Park, CA: Russell Sage Foundation

See Also

metabin, metacont, print.meta

Examples

# NOT RUN {
data(Fleiss93)
m1 <- metabin(event.e, n.e, event.c, n.c,
              data = Fleiss93, studlab = study,
              sm = "RR", method = "I")
m1
metacum(m1)
metacum(m1, pooled = "random")

forest(metacum(m1))
forest(metacum(m1, pooled = "random"))

metacum(m1, sortvar = study)
metacum(m1, sortvar = 7:1)

m2 <- update(m1, title = "Fleiss93 meta-analysis",
             backtransf = FALSE)
metacum(m2)

data(Fleiss93cont)
m3 <- metacont(n.e, mean.e, sd.e, n.c, mean.c, sd.c,
               data = Fleiss93cont, sm = "SMD")
metacum(m3)

# }