Medical professionals are inadvertently harming an unacceptable number of patients, an article in today's New Zealand Medical Journal says.
More than 1500 people were killed or permanently disabled annually through preventable medical error, Auckland University School of Population health lecturers Mary Seddon and Alan Merry said.
The toll was almostfour times last year's road toll.
Almost 13 per cent of patients in acute-care hospitals were victims of "adverse events" the authors said.
About 3000 were killed or permanently disabled. About 1500 were due to preventable medical errors.
"Any physician will know there are errors happening every day," Dr Seddon said.
Most errors involved elderly or very sick patients, most of whom would have died within three months if there had been no adverse event.
But medical error was still a "substantial health problem", the article said.
Comparing New Zealand figures to other Western countries, Australia was the worst performer, with 16.6 per cent of patients there experiencing medical error and 2.3 per cent killed or disabled.
Denmark had the lowest rates, at nine per cent and 0.4 per cent respectively.
The article explained adverse events as involving people trying to do the right thing, but actually doing the wrong thing.
That included non-preventable errors such as giving antibiotics to a person not known to have an allergy to them.
Errors could not be eliminated simply by exhorting staff to try harder and the focus must fall on improving the design of New Zealand's healthcare system.
"At present the system is highly complex, poorly co-ordinated and very prone to error," the authors said.
