Why we still ignore the evidence
Surely doing no harm also means not doing useless things to patients.
In many ways evidence-based medicine (EBM) is an outcome of this principle — if you only provide interventions that are effective, you are less likely to do harm.
So we spend a lot of money and effort on research to find the evidence we need.
Traditionally EBM applies to an individual — what is the best intervention for this patient at this time.
EBM takes on a whole new meaning when you think of it at a government/health system level.