[R] Metafor: Moderator variables for each study arm

[Faiz Ahmad Khan]

Hello,

I am trying to do a meta-analysis where each study has two arms, similar to the BCG data set. However, follow-up duration was different for each study arm, so I would like to fit a model that uses the length of follow-up in each arm as a moderator. Is this possible?

For example, if this was the BCG data, each study would have 2 follow up variables: 1 for the treatment group, and 1 for the control
group. 

thanks for the help,
Faiz

.