Hi there, I am using brms to estimate my fairly conventional meta-analysis model as follows:

yi | se(sei, sigma = TRUE) ~ 1 + mods

In my “new to brms” precociousness, I am now wondering if it’s possible to extend this simple model to include additional observations for which sei are missing. For observations with missing sei, I’d like to impute them based on a model, something along the following lines

yi | se(sei, sigma = TRUE) ~ 1 + mods etc

sei ~ 1 + mods (only when sei is missing)

Does anyone have any pointers on how to set-up the formula for such a model? Apologies if the answer is obvious, I’m fairly new to the wonderful world of brms. I did read this vignette on missing values yet remain unclear on the best way to proceed:

https://cran.csiro.au/web/packages/brms/vignettes/brms_missings.html