[R-meta] I2 interpretation for Multilevel meta-analysis with moderators

[Ivan Jukic]

Dear all, 

I'm currently conducting a multilevel meta-analysis with moderators. While the interpretation of the I2 for the "regular" multilevel meta-analysis is pretty much straightforward, I found it very confusing when moderators are added to the mix. 

I read, among other resources, the following:
http://www.metafor-project.org/doku.php/tips:i2_multilevel_multivariate
https://stat.ethz.ch/pipermail/r-sig-meta-analysis/2017-November/000377.html
https://stat.ethz.ch/pipermail/r-sig-meta-analysis/2019-September/001756.html
https://stat.ethz.ch/pipermail/r-sig-meta-analysis/2017-August/000138.html

Even after reading all of this, I'm still a bit unsure about the interpretation. 

So, if I run the following:

res <- rma.mv(yi = yi,
               V = vi,
               data = data,
               random = ~ 1 | Study/es_id,
               method = "REML",
               test = "t",
               slab = Study, 
               mods = ~ mod1 + mod2 + mod3)

and obtain total I2 of 68.35% for this model, does this mean that after accounting for variance via moderators, the remaining variance unaccounted for study and effect size is 68.35%. 

I came up with this interpretation while reading one of the posts on this SIG (linked above). However, I'm not sure if it's correct, and to be honest, completely understand the meaning of "the remaining variance *unaccounted* for study and effect size". Therefore, I would really appreciate if someone could clarify the interpretation of the I2 for multilevel meta-analysis with moderators. 

Cheers,
Ivan