[R-meta] correlated outcomes

[Luke Martinez]

Hello All,

A quick question. I have some labs that have conducted multiple
studies each targeting several outcomes, like:

labID  studyID  outcomeID
1         1            1
1         1            2
1         2            1
1         2            2
2         1            2
2         1            3

Then, can I allow correlated random-effects for outcome at the labID
level?  like:

random = list(~ outcomeID | labID, ~ outcomeID | interaction(labID,studyID) )

A part of me says that "~ outcomeID | labID" doesn't make sense,
because outcomes are only nested in studies, in which case, I should
only use:

random = ~ outcomeID | interaction(labID,studyID)

Am I correct in my thinking?

Thanks,
Luke