Now, an article written by the editors of the Lancet has called on New Zealand to address the inequalities.
"The apparent widening of longstanding health disparities based on economic position and ethnicity in a country that has repeatedly tried to narrow differences is disappointing, and prompts questions about the effectiveness of current policies for health equity," the article says.
"Disparities have changed little for either the Maori or for Pacific peoples (who together constitute a fifth of the population in New Zealand) in the past two decades. More effective solutions are needed."
After the shocking figures were revealed last month, Prime Minister John Key agreed the health gap was a wider social issue that needed to be addressed.
But Health Minister Tony Ryall today (Fri) said the Government had taken practical and proven steps to address infectious diseases in New Zealand, and was making significant progress.
The Government had invested $24 million in stamping out rheumatic fever, lifted immunisation rates from 70 per cent to 92 per cent in the past four years and invested more than $340 million in a home insulation programme, he said.
"We have also expanded WellChild visits and B4 School Checks so we can identify disease much sooner.
"B4 School Checks have been boosted from 3,000 in 2008 to over 100,000 and climbing, with a particular emphasis on high needs communities, and we are investing an extra $21 million which will mean an estimated 54,000 more WellChild visits," Mr Ryall said.
Labour health spokeswoman Maryan Street said the Lancet was "hugely prestigious", and the implications of having New Zealand's policies questioned in it were serious.
"People will be shocked that New Zealand has these kinds of problems. It will be a hit on our reputation and that is a shame," she said.
Ms Street noted that there would have been changes since the study ended in 2008, but agreed that more work needed to be done to fix poverty.
"This Government has not done anything about affordable housing. While it has improved and continues to work on insulating houses, more needs to be done to help private residential homes as well as state houses."
The editorial accompanies the publication of the research by Associate Professor Michael Baker and his colleagues.
Mr Baker has called for a "concerted multi-sectoral government response", to include contributions from tax and welfare policy, employment, housing, and education.
"We hope that our Government and the health and science communities will rise to these challenges," he said.
Professor Diana Lennon, head of clinical paediatrics at Auckland University said the health gap is a "sad indictment of the powerful" in New Zealand.
"Middlemore Hospital has a winter roster for pneumonia because they can't cope without doubling their staff. That doesn't happen in Melbourne, Sydney, or London. It's non-sensical and it doesn't make economic sense either.
"People can't believe New Zealand is like this because we had this wonderful reputation from the 1940s where we were progressive with our social legislation, but boy, we've slipped the other way and we're slipping further."
She estimates that 10,000 hospital admissions could be saved every year if the number of Maori and Pasifika hospitalisations were "reduced to Pakeha levels'.
"It's nuts. The rates were always awful - we've had rheumatic fever for 30 years and nobody's been listening, but now the numbers are changing.
"Now one in three kids in New Zealand is Maori or Pacific and they're carrying this socio-economic stuff with them and they're becoming economically more important, so people are starting to pay attention. It's a very cynical viewpoint, but I'm afraid that's where it is."
Dr Cameron Grant, Associate Professor at Auckland University and paediatrician at Starship Children's Hospital, agreed.
He said: "We must eliminate the current inequities in health that exist between indigenous and non-indigenous New Zealanders and in population subgroups such as Pacific children and children living in more deprived households."
More preventive health strategies for Maori and Pasifika are urgently needed to reverse the "disturbing trend in increasing disparities", says Professor Chris Cunningham, Director of Massey University's Research Centre for Maori Health & Development. Dr Nikki Turner, director of Auckland University's immunisation advisory centre, added: "There are economic, social and medical interventions that can and should be considered to address this problem, and as a society we need to address this urgently."
