# Cumulative meta-analysis

### Description

Performs a cumulative meta-analysis.

### Usage

1 | ```
metacum(x, pooled, sortvar)
``` |

### Arguments

`x` |
An object of class |

`pooled` |
A character string indicating whether a fixed effect or
random effects model is used for pooling. Either missing (see
Details), |

`sortvar` |
An optional vector used to sort the individual studies
(must be of same length as |

### 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`

.

### Value

An object of class `c("metacum", "meta")`

with corresponding
`print`

, `plot`

function. 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. |

`tau` |
Square-root of between-study variance. |

`df.hakn` |
Degrees of freedom for test of treatment effect for
Hartung-Knapp method (only if |

`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 |

`TE.random, seTE.random` |
Value is |

`Q` |
Value is |

`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.preset` |
Prespecified value for the square-root of the
between-study variance |

`TE.tau` |
Overall treatment effect used to estimate the
between-study variance |

`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. |

### Author(s)

Guido Schwarzer sc@imbi.uni-freiburg.de

### References

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

### See Also

`metabin`

, `metacont`

, `print.meta`

### Examples

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | ```
data(Fleiss93)
meta1 <- metabin(event.e, n.e, event.c, n.c,
data=Fleiss93, studlab=study,
sm="RR", method="I")
meta1
metacum(meta1)
metacum(meta1, pooled="random")
forest(metacum(meta1))
forest(metacum(meta1, pooled="random"))
metacum(meta1, sortvar=study)
metacum(meta1, sortvar=7:1)
meta2 <- update(meta1, title="Fleiss93 meta-analysis",
backtransf=FALSE)
metacum(meta2)
``` |