New Zealand's most-deprived children are suffering the most from preventable diseases, according to the third State of Child Health report released on Tuesday by research charity Cure Kids.
Māori, Pasifika, and children living in areas with the most poverty were disproportionately affected by respiratory conditions, skin infections, rheumatic diseases and mental health conditions.
The researchers behind the report said it was unacceptable, unfair and needed to change.
"They're not new things," public health physician Dr Sainimere Boladuadua said.
"We've had them for years - we've had them for decades. The definition of insanity is doing the same things and expecting something different."
Professor Stuart Dalziel, chair of child health research at the University of Auckland, said it was concerning that some of the biggest problems in child health were avoidable conditions.
"Over half the admissions into hospital covered by this report are preventable," he said.
"So, what we need to do is get our rates of disease for all children at the lowest possible level so that the highest rates of health exist for our children."
The report focused on four main conditions that impacted young people: respiratory conditions, rheumatic fever and heart disease, skin infections and mental health conditions.
Among the factors contributing were high rates of child poverty, unhealthy housing and inadequate access to healthcare services in some areas.
The report found that these conditions affected some children much more than others. Between 2017 and 2021, Pasifika children were more than 100 times more likely to be hospitalised with rheumatic fever than children of European or other ethnicities, while Māori were 40 times more likely.
Dalziel said this was not good enough.
"It makes me incredibly angry that we still have these disparities existing in our country; that our rates of respiratory disease, skin disease, rheumatic heart disease, and mental health illness are some of the highest in the world.
"Our children deserve better, and so we need to make these conditions a priority. We need to make child health a priority in this country, and we need to start addressing these things in a real, meaningful way."
Although rheumatic fever and heart disease were most common in low- or middle-income countries, New Zealand's rates of both were among the highest in the developed world.
Cure Kids chief executive Frances Soutter said New Zealand should be "so embarrassed" that these preventable diseases continued to hospitalise 200 kids a year on average, the vast majority of them Pasifika or Māori.
"What I get disappointed about is we can eradicate Covid and limit it, but we've got rheumatic fever and rheumatic heart disease in this country - which are third-world diseases - and because it's a small group of people that are impacted by it, it doesn't get the same momentum."
While many childhood vaccinations were free, researchers said that did not necessarily translate into kids getting vaccinated, with other barriers standing in the way such as a lack of transport.
Mental health specialist Dr Terryann Clark said it was a similar story with mental health services - just because they existed did not mean they were reaching who they needed to.
"Families can't get services, there are huge wait times, so there is a huge mismatch between service delivery and the need that's happening out there in the community."
This was the first year the State of Child Health report had prioritised mental health concerns. It highlighted the rate of under-19s admitted to hospital with mental health diagnoses had doubled in the past 15 years.
Clark said mental health services were unfit for purpose and were often unavailable when kids needed them most.
She said innate discrimination within the health system did not help.
"Māori are less likely to be able to access care. When they do access care, they are less likely to be taken seriously. When they do get taken seriously, they are less likely to be referred on to mental health services, and less likely to receive quality care.
"There are so many steps along the way where there is discriminatory healthcare provided."
Clark said mental health practices developed overseas were not always appropriate in New Zealand, and needed to be targeted to the specific needs of the population with a strong focus on community-level support.
The researchers said a collaborative effort between themselves, the government, and health workers was what was needed to make a difference.
With a new Budget coming on Thursday, they were hoping to see the government place a greater priority on child health - an investment they said would pay off many times over by helping to prevent chronic health issues later in life.