In France, for me, it depends on what age it was.
being a student, at school physicals, it was always in brief at elementary or middle school since all the class or half of the class has been instructed to undress until briefs in a locker room all together and to wait our turn for the examination.
it was a mandatory annual examination and it was necessary performed at the nurse'office of the school with the school doctor assisted by a female nurse, it was not admitted to substitute a medical form filled by a family doctor to that examination at school.
after at high school, from 15 to 18 age, it was stark naked since we had to remove our brief before entering in the examination room according to the instructions of our Pe teacher who supervised us in the locker room.
for military service, it was always stark naked at 18 age in a pre-indiction center or in front of the draft board commisssion. and the same after being inducted a few years after when undergraduate.
at university, it was in brief.
for job, it depends but when I began to work, it was generally in brief and later it was sometimes in trouser and chare best
at a doctor'soffice, there is no rule, more often for a chek up, it is in brief but sometimes it can be still dressed above all todays.