Health sector leaders have been urged to listen more closely to complaints and whistle-blowers.
A report this year by a British barrister and leading patient safety advocate, Robert Francis, into major failures at a Staffordshire hospital sent shockwaves through the health system worldwide.
At a workshop in Wellington on Monday, Mr Francis said that problems raised by families, doctors, nurses and others in mid-Staffordshire were not listened to.
He said it led to harrowing events, including patients being left in their own excrement, or without drinking water, for days.
Mr Francis said everyone needs reminding patients should not be harmed, that complaints should be investigated and that much more openness is needed in the health system.