Not long ago I was talking to the CIO of a major hospital - won't say which one ;) - and describing how the Brazilian national EMR uses URIs to render unnecessary the traditional names, addresses, and other identifiers which many people in the Amazon River Basin simply don't have.
URI - Universal Resource Identifier.
His reaction surprised me. First, that he had not heard of this, a nationwide paperless medical record system, the largest open source project in the world, funded in part by the United Nations global health fund. I came across it through the open source Java community. Then he asked, "Why can't we have a universal identifier?"
So right now I am telling you to forget about universal identifiers. Not in this country. Instead start thinking about something better:
Organizational identifiers and computational inferences of equivalency.
I just started studying the IHE technical framework, and I have not yet dug into the guts of the live system, but I'm already getting the feeling that this approach is more in line with how I have been thinking about things.