My experience with my Dad was that they (hospitals) are pretty casual about it. They asked me if I had one and said I’d need to bring it next time I came. It sounded more like it was for record keeping more than anything, red tape etc. Now I can imagine that it could be a pretty big issue if two different parties are asking them to do different things but if you know you have an adversarial relationship with others who may be involved, it would be best to be prepared for that eventuality, wouldn't it?

G