Researchers have found an increasing number of smokers are using e-cigarettes to try to quit.
The study by the University of Otago, Wellington, shows greater awareness and use of e-cigarettes among smokers and those who recently quit.
Almost a quarter of daily e-cigarette users had recently quit smoking and the vast majority say they used the products to quit or cut down on smoking.
The study's principal investigator, Professor Richard Edwards, said e-cigarette use was most common among those aged 18-24 years and among those who had recently quit smoking.
The research was part of the New Zealand arm of the International Tobacco Control Policy Evaluation project and involved surveys with 1155 people between 2016 and 2017 and 1020 people in 2018 - 400 of them Māori - who smoked or had recently quit smoking.
Participants came from New Zealand Health Survey and were asked about their awareness and use of e-cigarettes, reasons for use and related beliefs.
The 2018 survey showed a high awareness of vaping devices, with 98 percent of smokers and recent quitters saying they were aware of e-cigarettes - 77 percent reported trying vaping, while 22 percent used e-cigarettes at least monthly and 11 percent daily.
Use was similar between Māori and non-Māori participants, Edwards said.
Daily use was greatest among recent quitters (23 percent) compared to current smokers (8 percent) and among 18-24 year olds (19 percent) compared to older age groups (10 percent). The most common reasons given for using e-cigarettes were to help quit (78 percent) or cut down on smoking (81 percent).
"This suggests e-cigarettes are contributing to reducing smoking prevalence and to achieving the goal of Aotearoa becoming smokefree by 2025," Edwards said.
"However, it is of concern that e-cigarette use is more prevalent among 18-24 year olds. If e-cigarettes are to make a substantial contribution to reducing smoking, their use needs to be greater among older age groups."
While the research shows more people are using e-cigarettes to quit smoking, more smokers reported using e-cigarettes on a trial basis, rather than regularly, which suggested there might be barriers to more sustained use, he said.
"The most common potential barriers identified were that 68 percent of participants thought vaping was less satisfying than smoking and 39 percent incorrectly believed that e-cigarettes were as or more harmful than smoking cigarettes, or were unsure (15 percent)."
The most common motivation for using e-cigarettes was to save money compared to smoking, suggesting taxes to keep the price of cigarettes high relative to vaping might motivate more smokers to quit.
There's growing evidence e-cigarettes may be a net positive to the population by helping smokers quit, but caution has to be exercised to ensure younger people do not take up vaping, he said.
"We really don't want to perpetuate nicotine addiction and possible harms from vaping or anything else into the next generation, so we've got to get that regulatory balance right and that's what the vaping legislation that's just been through Parliament aims to do. Obviously we and others will be monitoring that to see if we can find out that's how it turns out," Edwards said.
"The key thing is reducing smoking. That's always the key thing, because it has so much in the way of adverse health effects, and vaping may help but it's not enough."
Edwards urged the government to introduce a comprehensive plan on how New Zealand could become smokefree by 2025, because while vaping might help get us there, it's not going to be nearly enough.
"We need to do a whole load of other things and we need the government to step up and put in place in other policies to regulate smoked tobacco products, for example making them less widely available or reducing the nicotine in those products, so that we can get rid of smoking for good."