So, why not have a stipulation added. Say at a cost of approximately £20 per letter, whereby a professional pilot has to go to his GP and request a letter stating that for the previous 12 months he has had no visits to the doctors for what could be a set of issues ie mental/serious physical. This letter can be emailed by the gp, using the pilot ref number, to the CAA medical branch and entered onto the file of the pilot in question.
But the pilot will just go private (as used to happen in, say, the military) for "concerns" he wishes to keep off the radar?