Preventing medical errors:
Interestingly, the single biggest "fix" for that, is Checklists for the doctors & nurses. The USA research results are really quite startling, in terms of collapsing the error rates.
There was a push a few years back in the USA to roll them out mandatorily.
Unfortunately, there's strong pushback by the medical staff. Takes the fun out of the job, or they feel it belittles their professionalism, or something, apparently.