Dear All,

I hope all is well.

I have a question about the I-squared heterogeneity statistic in meta-analysis. I run this meta-analysis using command ‘rma’ which is in the R-package ‘metafor’.

In my understanding, heterogeneity in a meta-analysis is the measure of between study variability which is not due to sampling variability (within study variability).

Currently I am analyzing data from multivariate models from different studies with different study size, years of follow-up and from different countries. I wonder whether in my case the heterogeneity statistic would take into consideration all the above mentioned differences?

If the above mentioned differences are not included in heterogeneity statistic, how else can they be accounted for within a meta-analysis equation?

Thank you in advance for your advise.

Kind regards,

Joseph