Testing heterogeneity across sample populations

#1
I have 12 datasets collected from different centres with a dependent categorical variable (yes/no) and several independent variable that are both categorical and continuous. I want to check how heterogeneous the datasets are with the intention of combining them into one dataset and carrying out a logistic regression. Is there a specific statistical test I can use to do this? Thanks :)
 

hlsmith

Not a robit
#2
Are you interested in investigating multiple IVs or just one? Do you think the heterogeneity is across multiple variable or within a certain feature?

Regardless, it may be appropriate to consider multi-level modeling, random effects. Within it there is the intraclass correlation test to see if controlling for each set explain additional variability in the model.