These articles were written before our ownership of IMTJ, so it's difficult to say. It sounds like the "media speak" of medical tourism conference speeches and industry associations. Somone somewhere in the industry invents the phrase "medical hub" or "medical city". No one defines what this means. Then someone else comes up with an invented number of how many of these there are to support some claims about the growth of the industry.
What is a medical hub city? London is a case in point. Is London a medical hub city? It probably earns more revenue from treating overseas patients than most of the new "medical cities" established around the world, but is probably not considered as a "medical hub".
Is Budapest a medical hub city? It attracts many patients from outside Hungary who visit an extensive and disparate number of healthcare providers. Does this constitute a "medical hub city"?
So back to your question. We can't answer it. And those who claim to know which are the top 20 or top 40 international medical hub cities worldwide......are probably talking through their hats!