Yesterday I was "interviewed" by Panagiotis Petrou, who is working within the EU project Adapting European health systems to diversity (ADAPT). [He did suit up for the "interview", while, because it was in my office, I wore my normal work clothes. On second thought, I probably should have done a Barney...]
We had been in contact via email for a health economic model he was working on (and for which I informally suggested a few things) and then he asked me if I could share my thoughts on the issue they are trying to tackle.
As I understand it, their main objective is to think of how to deal, from the health economic point of view, with ethnically and culturally diverse sub-populations who may not have rights to access to public health systems around Europe, but who end up being treated anyway in accordance with the principles of universal access.
That's an interesting problem and of course it has quite clear health economics impact, because these sub-groups of the population might end up accessing high-cost emergency treatments for conditions that may have been controlled using routine service (eg GPs). But in many cases this is not possible, because they are "out of the system".
But the problem is more complex than that, because before you can even think of the health economics of it, there's the whole political issue to be accounted for $-$ different countries even within the EU may have different approaches to how "aliens" are treated and who pays for that.
Perhaps it has quite a few links with works being developed to study unauthorised migrations (eg this and this). I did mention this aspect to Panagiotis and given that both streams have connections with the EU it may even be easier to combine them. Or not?