metafor (version 1.4-0)

cumul.rma.uni: Cumulative Meta-Analysis for rma.uni Objects

Description

The function cumul.rma.uni repeatedly fits the specified model, adding one observation at a time to the model.

Usage

## S3 method for class 'rma.uni':
cumul(x, order=NULL, digits=x$digits, transf=FALSE, targs=NULL, \dots)

Arguments

x

an object of class "rma.uni".

order

an optional vector with indices giving the desired order for the cumulative meta-analysis.

digits

an integer specifying the number of decimal places to which the printed results should be rounded (the default is to take the value from the object).

transf

an optional argument specifying the name of a function that should be used to transform the model coefficients and interval bounds (e.g., transf=exp). Defaults to FALSE, which means that no transformation is used.

targs

optional arguments needed by the function specified under transf.

...

other arguments.

Value

• An object of class c("list.rma","cumul.rma"). The object is a list containing the following components:
• estimate
  estimated coefficients of the model.
• se
  standard errors of the coefficients. NA if transf is used to transform the coefficients.
• zval
  test statistics of the coefficients.
• pval
  p-values for the test statistics.
• ci.lb
  lower bounds of the confidence intervals for the coefficients.
• ci.ub
  upper bounds of the confidence intervals for the coefficients.
• QE
  test statistics for the tests of heterogeneity.
• QEp
  p-values for the tests of heterogeneity.
• tau2
  estimated amounts of (residual) heterogeneity (only for random-effects models).
• I2
  values of $I^2$ (only for random-effects models).
• H2
  values of $H^2$ (only for random-effects models).
• The object is formated and printed with print.list.rma. A forest plot showing the results from the cumulative meta-analysis can be obtained with forest.cumul.rma.

Details

The model specified by x must be a model without moderators (i.e., either a fixed- or a random-effects model).

References

Chalmers, T. C. & Lau, J. (1993). Meta-analytic stimulus for changes in clinical trials. Statistical Methods in Medical Research, 2, 161--172. Lau, J., Schmid, C. H. & Chalmers, T. C. (1995). Cumulative meta-analysis of clinical trials builds evidence for exemplary medical care. Journal of Clinical Epidemiology, 48, 45--57. Viechtbauer, W. (2010). Conducting meta-analyses in R with the metafor package. Journal of Statistical Software, 36(3), 1--48. http://www.jstatsoft.org/v36/i03/.

See Also

cumul, forest.cumul.rma

Examples

### load BCG vaccine data
data(dat.bcg)

### calculate log relative risks and corresponding sampling variances
dat <- escalc(measure="RR", ai=tpos, bi=tneg, ci=cpos, di=cneg, 
              data=dat.bcg, append=TRUE)

### random-effects model
res <- rma(yi, vi, data=dat, method="REML")

### cumulative meta-analysis
cumul(res, transf=exp, order=order(dat$year))