As others have said, it's not likely to be useful to medics when you are unconscious. However, it might be useful to you if you are conscious, and it has stuff you can't remember. If some kind of disaster strikes while you happen to be on the road, and you become a de-facto refugee, then there's a lot of information relating to who you are, what you can do, and what assets you own, that can be valuable. The sort of stuff you would want to have on you if you were bugging out.