TLDR for non doctors: a lot of people who are on the older side take anticoagulants or anti-platelets, and when they hit their head on the front porch, with no other symptom but a small bruise, if they go to an ER they have to undergo a useless CT scan.

This is a cost for them, time wasted for the hospital team, and increases their lifetime risk of sickness because it's a bit ox X-rays one could do without.

This team is working on showing what everybody knows - that is, the scan is not useful - so everybody can do the right thing.