[R] R: interpreting weight in meta-analysis of proportion

[Mario Petretta]

Fine !

Many many thanks!

Mario


-----Messaggio originale-----
Da: Bernd Weiss [mailto:bernd.weiss at uni-koeln.de] 
Inviato: venerdì 18 aprile 2014 15.58
A: petretta at unina.it; R-help at r-project.org
Oggetto: Re: [R] interpreting weight in meta-analysis of proportion

On 18.04.2014 13:02, petretta at unina.it wrote:
> Prof. Dewey, sorry for the trivial question and many thank for the replay.
> 
> 
>> Using which package?
> 
> In this case I used the meta package, but I know that for all but the 
> DerSimonian-Laird method the R function rma.uni of R package metafor 
> is called internally.
> 
>> What did you expect the weights to sum to, I wonder.
> 
> I think that, to better explain the influence of single study in 
> pooling the effect size, the weight are presented as percentage of the 
> sum of total weight of each study, but I ask for a confirm. 
> Nevertheless, I ask if it is possible to obtain for each study the 
> value of the absolute weight, other than the relative weight, or at 
> least the absolute value of the sum of the weights.
> 

## This is an example from the examples-section res <- metaprop(4:1, c(10,
20, 30, 40), comb.fixed=FALSE, comb.random=TRUE)

## Object res contains a lot of interesting information ## Open ?metaprop
and read the section on "values"
str(res)

## Obtaining the random-effects weights
res$w.random

## Calculating relative weights manually
res$w.random/(sum(res$w.random))

HTH,

Bernd