Research shows traditional Māori woven bassinets are saving infants' lives.
Previous studies found the introduction of wahakura in 2005 saw a 29 percent drop in sudden unexpected deaths between 2009 and 2015.
And now two of the researchers behind their introduction have looked at why they've been such a success.
Previous attempts to lower the rate of sudden unexpected death in infancy (SUDI, formerly known as 'cot death') had worked for other ethnic groups, but not Māori.
"Maori were rejecting the 'stop bedsharing' SUDI prevention message and the SUDI disparity between Māori and non-Māori had become entrenched," researchers David Tipene-Leach and Sally Abel wrote in a new article, published in the Australian Journal of Primary Health.
Rates of SUDI fell 60 percent in the early 1990s following a campaign warning parents:
- not to put their babies to sleep facing downwards
- not to share their bed with their infant
- not to smoke.
But rates among Māori remained high, leading to a "persistent five-fold disparity between Maori and non-Maori rates".
"The statistics were about four per 1000 nationally - which was around one to two per 1000 for non-Māori, and around about eight for Māori," Dr Tipene-Leach told Newshub.
By 2005, he and others were convinced bassinets were the answer - and decided flax-woven Māori bassinets were the "culturally resonant" answer.
Alongside the plastic equivalent, the Pepi-pod, the scheme worked - overall infant mortality dropped by almost a third, "primarily among Maori infants". The rate is now around twice that of other groups.
Dr Tipene-Leach says wahakura are now a popular item.
"There's a generation of young women now who don't remember when we didn't use wahakura. There's a new generation coming who think wahakura have been here forever," he says.
In the new article, Dr Tipene-Leach and Dr Abel say the programme worked because "it was designed for a specific target population, by members of that population, using cultural maxims derived directly from that population group".
"It thereby avoided a common outcome of many new health interventions that improve outcomes for dominant groups but produce, or increase, disparity for disadvantaged groups."
The Ministry of Health in 2016 canned funding for wahakura, saying there wasn't enough evidence they work. It was overruled by then-Health Minister Jonathan Coleman, who the following year unveiled a $2 million scheme to roll them out to "all families deemed at risk of bedsharing".
Dr Tipene-Leach in 2017 said hundreds of lives had been saved by wahakura, but officials didn't "give a toss" because it was Māori babies who were being saved.
"If they were babies from Glendowie and Remuera who were no longer dying there would be huge philanthropic money that came in," he told Stuff.
Around 60 infants still die each year in New Zealand as a result of SUDI.
Despite the success, Dr Tipene-Leach says smoking still needs to be addressed - previous research has shown the chance of SUDI is increased by 32 times if a baby is exposed to smoking and bed sharing.