This used to be a problem in medicine too (probably still is for some
older practitioners). The BMJ has had a decades long campaign in
favour of evidence-based medicine that has been bearing fruit.
Did you know that there was no value in swabbing alcohol on skin
before an injection? It just seemed such a naturally obvious good
idea....
It is still a major problem with psychiatrists who like to believe in
a magical drug-rep assisted ability to prescribe powerful mind-
altering drugs for conditions that have not been tested or authorised
(off-label prescribing - which seems like a macho thing for shrinks to
do).
One argument for public, as opposed to private, medicine is that
public bodies don't allo shrinks to get away with this sort of
expensive abuse.