Corrected emergency department wait data will be published on Friday, Health Minister Ayesha Verrall says, and the incorrect data was not used to make decisions.
She said media reports that quoted her directly referring to the incorrect data were false.
Te Whatu Ora (Health NZ) on Thursday morning admitted the data it had published on emergency department wait times was clearly "not accurate".
It came after National Party health spokesperson Shane Reti had raised concerns about the published data, having regularly called for such data to be published since last year.
On Thursday afternoon, Dr Verrall told reporters she had called officials in to explain how the error occurred.
"Their underlying data collection and collation methods, they assured me those were sound but there was an error in the publication of a report on their website in January - so it's a publication error," she said.
"Two things, one was an error in the spreadsheets that were used to prepare the data, and then secondly of the two quality assurance checks that normally happen, one did not happen.
"People make mistakes with spreadsheets from time to time."
She said the incorrect published data was never used for decision making.
"The only data set that has got an error in it, I'm told, is the one that was published to the public. The one I used, the board used, decision-makers in the health system used, was correct."
The incorrect data set was pulled from Te Whatu Ora's website on Thursday, and chief executive Margie Apa apologised.
Verrall said officials had also apologised to her directly. The errors would be fixed and the correct data would be published on Te Whatu Ora's website on Friday, she said.
"I've asked Te Whatu Ora to go and review their data quality assurance processes so that the public can have that assurance that good data in our health system is being provided."
Media reports - which quoted her referring to the incorrect data and saying wait times were reducing - were wrong, she said.
"I did not say that, but my office did provide a link to that data that we now know is inaccurate.
"I accept that it must have been extremely frustrating to the staff in emergency departments who saw those false comments attributed to me. I spent a lot of time talking to them to understand the true picture and I'm disappointed those didn't come across.
"I've visited three ED departments since I've been in this role and I hear about a variety of pressures. It includes more people coming because of difficulties accessing primary care; it includes the difficulty discharging people from the hospital, and so that backs up through into the emergency department.
"Last year, of course, winter ailments - both flu and Covid - were a contributor which is why I prioritised vaccine campaigns again this year."
ACT health spokesperson Brooke Van Velden said people should expect to be getting correct data.
"It's clearly wrong that the data is showing there isn't a problem in areas around the country when people and doctors on the ground are telling us it is. And this issue should be rectified immediately.
"It's vitally important that the information that ministers and the opposition are receiving is correct because we need transparent information - but it has to be accurate so that we get resources to the area it's needed."
Green Party co-leader Marama Davidson said it was not her area of expertise and she had not seen the reports, but officials always needed accurate data.
"No one should ever confuse us with data that isn't right. I know that's not always available to have accurate data but we need accurate data to make good decisions."
Important to get data right, even more important to do something - GP
Association of Salaried Medical Specialists head Sarah Dalton said mistakes happened.
"Although I would have thought those numbers would have caused someone to have looked a bit more deeply at it, because we don't have any EDs at the moment just chundering along untroubled."
Clinicians had been very worried about the lack of useful data long before Te Whatu Ora arrived on the scene, she said.
"One glimmer of hope potentially is that with a whole of country system at some point they might get across the data to the point where we might have more accurate datasets and shared methodologies, so we know what is there is more or less accurate."
Te Whatu Ora was currently working on a real-time data collection system, which would allow hospitals to identify pinch-points immediately and take action, rather than the monthly reporting, she said.
Whangārei emergency doctor Gary Payinda said it was important to get the data right - but it was more important to actually do something about it.
"Number targets can always be gamed and there's always ways to get the number you desire. So we have to be a little bit more holistic than that, and take the numbers in context."
Dr Payinda, a past elected member of Northland District Health Board, said the reality was that successive governments had massively under-invested in health and it was going to take a huge cash injection to fix the problem.
"If we don't confront this we will end up with what I left in the United States many years ago: a fragmented and failing society that pits one race or group against the other, with both sides losing. The only winners in this are the very wealthy. They've had a good run of tax avoidance and achieved levels of wealth hoarding that haven't been seen in New Zealand in 70 years."
An 'exodus' of doctors
MedRecruit executive chair and owner Sam Hazeldine told Checkpoint up to 30 doctors a month were heading over to Australia to work.
"We're seeing huge numbers. I look at it and say it's an exodus."
MedRecruit used to see doctors seeing both ways, he said, but since Covid-19 not one doctor has come here from Australia for locuming - the medical industry's version of freelancing.
In Australia, doctors get paid more and resource had been thrown at the frontline, he said.
Increased numbers of doctors in New Zealand were leaving permanent work, choosing to go locuming.
Hazeldine said there should be data showing exactly how many doctors New Zealand was short.
"I'd have to say we're over 5 percent, 10 percent short of doctors."