ACC Building in Wellington Photo: RNZ / Angus Dreaver
ACC has paid out $92.7 million in roughly five years to people who haven't received medical treatment on time.
More than 1100 people were covered but that number did not reveal the full extent of those who missed out on care in the health system.
The claims were classed as "treatment injuries" even though they were for an omission of treatment.
For someone to qualify for ACC cover, they must prove the treatment (or lack of) caused an injury, and that the injury was not a necessary or ordinary part of the treatment.
The biggest proportion of money paid out was for a delay or failure to diagnose a condition - $46m. It covered 444 people.
That was followed by a delay or failure to provide treatment - $23m to 347 people.
There were several claims sub-categories - delay/failure to diagnose, delay/failure to follow up, delay/failure to provide treatment, delay/failure to refer, delay in delivery, failure to monitor, incorrect radiation, incorrect site, premature discharge and wrong surgery.
The spokesperson for advocacy group Patient Voice Aotearoa, Malcolm Mulholland, said he was not surprised by the figures.
"As one system fails, that being our public health care system, another system in the form of ACC is having to meet the shortfall," he said.
Missing out on treatment had the potential to have a catastrophic impact on some people's lives, he said.
Patient Voice Aotearoa spokesperson Malcolm Mulholland. Photo: RNZ / Jimmy Ellingham
ACC said the figures, which ran from the 2020/2021 financial year until this month, could only reveal so much.
"When considering treatment injury data, it is important to note that the number of claims lodged with ACC cannot be taken as an accurate indication of the occurrence of injury during treatment or the quality of care," the agency said in a document accompanying the figures.
"This is because, among other reasons, not all occurrences of injury during treatment are lodged with ACC."
Mulholland agreed the figures would not tell the whole story.
"I don't think many people would be aware that they have the ability to call on ACC in such situations," he said.
It was right that people got support, but $92 million of taxpayers' money could be put to very good use in the health system, if it was not needed to pick up the pieces, Mulholland said.
ACC said people whose claims were accepted could receive three types of support: compensation (such as for loss of earnings), treatment costs, and rehabilitation support help
"The biggest single factor in determining the long-term costs of some injuries is the amount of personal support needed by the client. Some treatment injury types may pertain to injuries, which may be minor and require little or no on-going support from ACC," it said.
The agency had accepted 1103 treatment omission claims in the period, and rejected 1268, it said.
The number of people claiming had not risen between the 2020/21 and 2024/25 financial years, and in come categories had fallen, but the amount paid out had gone from $2.6 mil to $31.5 mil.
ACC said that was because the cost of rehabilitation and providing cover and help had risen for most types of claims in that time
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