Leading anti-smoking campaigners say officials’ modelling wrongly suggested the Government’s plan would reduce smoking rates by 85 percent within five years

In a new review released early Monday morning, researchers from Action on Smoking and Health say the modelling underpinning the Government’s plan to mandate cigarettes be sold without nicotine is “significantly flawed”.

ASH director Ben Youdan told Newsroom the findings are not about saying that New Zaland shouldn’t do bold policies and actions to get rid of the harms of smoking. “It is about making sure that when we’re doing actions that are going to have such a profound effect on the smoking population and people who are struggling with nicotine dependence is that we need to do the due diligence to make sure they’re done equitably, fairly and they’re done in a way that’s going to mitigate harms to people.”

The minister in charge of the Smokefree 2025 plan, Associate Health Minister Ayesha Verrall, said she hadn’t relied too much on the modelling in question when designing the policy and the findings wouldn’t have changed her decision-making at the time.

“It was one input into how we came up with the package of measures that were included in the bill. There were a range of other things, including the feasibility of different measures, the time at which they would be expected to be implemented and have impact and legal advice as well, because all legislation on tobacco has to be considered for its legal risk,” she said.

“It was one part of the equation. It improves your decision-making but it doesn’t by any stretch make the decision for you.”

Under the legislation before the Health Select Committee right now, the Government will be able to regulate the nicotine content in all tobacco products.

Modelling commissioned by the Ministry of Health and referenced in Cabinet documents and the bill’s Regulatory Impact Statement suggests the denicotinisation could be expected to reduce smoking rates by 85 percent within five years.

Youdan says this is based on a misreading of a clinical trial on the provision of nicotine-free cigarettes to people who wanted to quit smoking.

“The assumptions that they put into the model are massively overestimating the likely impact of that policy.”

The trial provided people motivated to quit with behavioural support. Some also received nicotine-free cigarettes, while a control group didn’t. Six months on, 28 percent of those in the control group said they hadn’t smoked in the past week, compared to 33 percent in the denicotinised group.

The Government’s modelling assumed that denicotinising all tobacco products in New Zealand would lead to a 33 percent quit rate each year and an eventual 85 percent reduction after five years, which Youdan says is erroneous for a number of reasons.

First, the nicotine-free impact in the clinical study was only 5 percent – the bulk of the quit rate came from the behavioural support provided to all participants.

Second, the findings related only to six months after the trial began. There’s no reason to assume the quit rate would be compounded each year, year after year.

Third, the participants in the trial were motivated to quit while the Government modelling was intended to estimate the impact on the entire smoking population, including those who have no intention of quitting.

Finally, it didn’t take into account the reaction of smokers and tobacco suppliers, who might move to illicit sales or otherwise circumvent the denicotinisation regulations.

“Our concern is not that the model is bad, it’s that the assumptions that go into the model are problematic. When it comes to designing pretty substantial policy that’s going to have a major population impact, it doesn’t consider what the broader consequences of putting a couple of hundred thousand people into essentially forced withdrawal is genuinely likely to result in for those people,” Youdan said.

Removing nicotine from cigarettes was likely to reduce the uptake of cigarettes by new smokers and to help with cravings, but wouldn’t necessarily solve withdrawal issues and certainly won’t crash smoking rates, he added. Almost every study on the issue also involves wraparound behavioural support and access to alternative nicotine sources, which may do most of the heavy lifting attributed to denicotinisation anyway.

“The model was based on extrapolating the results from clinical trials. Any clinical trial, there’s a change in the effect you see when it’s applied in the real world. When I read advice that was based on the model, I had that in mind,” Verrall said.

“I was already approaching that with an appreciation it was an estimate and in real life there would be some movement around that.”

Given the findings of the review, ASH has asked the Government to have the modelling independently vetted and allow the most dependent smokers access to nicotine cigarettes in a controlled way.

Verrall said she would look at ASH’s review but suggested it probably wouldn’t change the Government’s direction.

“I always welcome scientific debate. I think, though, I am confident of the measures that we’ve got and I’m very pleased to be taking strong action to getting tobacco out of our community.”

Marc Daalder is a senior political reporter based in Wellington who covers climate change, health, energy and violent extremism. Twitter/Bluesky: @marcdaalder

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