If wanna estimate the country of SR/MA studies, what is right country of corresponding author or 1st author?

I think it is corresponding author, as it estimate supervisor lab or team country that this paper done in, as may authors have different countries

So what is estimate right country we can depend one, and if have references plz

Note: I know country can be known from patient country where trial done, but this is specific different issue where we want to give country for each SR/MA study we have in our included studies