When somebody is issued a hospital number eg A12345. Does anybody else in the country have the same number ?

It's just the local hospital.

Pretend it was national; that would mean everytime a person comes to the hospital, the nurse would have to register him in a huge online database after checking that nobody else has the same number. Not only would it be a waste of money, it would be pointless and waste time.

The only benefit is John Smith in Vancouver won't get mixed up with Jane Smithye of Toronto, and since they're so far away that's never going to happen anyways.

I think the number applies to the hospital you are in and coinsides with your name.

Using both a number and your name helps prevent patient mix ups.

no one has the same number im a nurse so i no