Hey guys,

As the title says, I really would appreciate your help with some issues I'm having with R(studio).

I Need to conduct an meta analysis and compare some studies in a forest plot. I'ts about pharmacological outcome data from several randomised controlled trials that I want to compare with each other.

I always have the Treatment difference and the 95% CI and the number of patients in active and placebo arms.

Assuming a normal distribution, I can calculate the SD and Se values of the Treatment difference TE from the TE and 95% CI values. And with that values TE and Se for all the studies I can make a meta analysis using the metagen function. I got so far.

I'm using an excel sheet from which I can just copy and ''paste" the data using control+c.

The code is

datenmean=read.table(''clipboard'',header=TRUE,dec='','',sep=''\t'')

datenmean

library(meta)

help(meta)

meta1<-metagen(TE,seTE,data=datenmean,sm=''SMD'')

summary(meta1)

forest(meta1)

forest(meta1,comb.random=TRUE)

funnel(meta1)

in the excel sheet I just need to fill in the rows with the information TE and Se (one row per study) and use control+c to drag it into Rstudio.

But how do you consider the amount of patients per study, because studies with many patients should get greater weight in the metaanalysis than studies with fewer patients, right ?

I would be really thankful, if someone could just tell me how to include a column for total patients active +placebo in my excel sheet and add something to the R code, so that the number of patients will be considered as well . Thank you very much !