[R-meta] Question metafor network meta-analysis with multiple time points

[Gerjon Hannink]

Hi all,

I have a `metafor` question, and hope you can help me out. I was
thinking of (and struggling with) how I would do a network
meta-analysis with studies with measurements at multiple time points
using `rma.mv` from the `metafor` -package. Would that be possible?

In many presentations (e.g. provided on
https://www.wvbauer.com/doku.php/presentations) I find 'multiple time
points' and 'network meta-analysis'. In these examples, the following
is used, e.g.,

`res <- rma.mv(yi, V, mods = ~ factor(time) - 1, data = dat.long,
random = ~ time | study, struct = "HAR")` and
`res <- rma.mv(yi, vi, mods = ~ trt, data = dat, random = ~ 1 |
study/trt)`, respectively.

Would it be as simple as just combining the two? I guess it is not
that simple...

I played a bit using something like:

rma.mv(yi, V, mods = ~ factor(time) * trt , data = dat.long, random =
~ time | study/trt)

But this returned an error message 'Cannot use '~ inner |
outer1/outer2' type terms in the 'random' argument'.
I guess I would also need to modify V a bit to take all necessary
variances/covariance into account...
And what about `struct`?

Thanks for your help & looking forward to hearing your thoughts!

Best regards,
Gerjon