Originally Posted by
Innocent Abroad
That, in fact, happened to me once
My partner once booked me on a trip and used the 'Dr'. While I don't know any more than I type here, on one of the flights, a crew member came and stood right next to my seat and asked loudly if there was a doctor on board as there was a passenger in need of attention. They might have spotted the 'Dr' on the manifest, or it might have been coincidence. I don't know.