Re: So a dilemma.
"But in this case the expense is too great: the expense is lives"
It's not. Really it isn't. Almost never. For routine medicine you can always wait a couple of seconds, and in most emergency cases you *treat what you see in front of you* not what some computer says. If there's blood spurting out I don't care that you had depression at University I want to stop the bleeding.
It's only a few oddball cases, including severe allergic reactions, that make the news where the information is relevant and for those a physical bracelet, card or pendant is much easier and harder to abuse.