Trying to remember how medicare cards were used in 1997, also keeping in mind that Grafton is a somewhat rural area, definitely not metropolitan, so perhaps they didn't have all the latest IT.
Today, your card number is in their computer system and that is linked via internet to a larger medicare database. So all that is required today, is for you to present card and they check it matches the one on file in the system, right?
But in the past you had to use a manual swipe machine with carbon paper so there were three copies, very similar to the old gadget used to swipe credit cards. A copy for patient, a copy for Dr, and a copy sent away to medicare so Dr got paid. Or am I imagining it
However, there were no checks made to ensure a person was using their own medicare card. There's no photo and they don't ask for other ID.
If you were using additional health insurance, those needed to match. But if it was a regular check up without purchasing glasses, then you wouldn't need to provide insurance details. Or you could just pay for additional expenses not covered by medicare out of pocket.
People don't usually use other people's medicare cards because all Aus residents have one and you typically ask for a new one if you lost your wallet, so old or stolen cards are void.