The Health Information and Quality Authority (Hiqa) is also concerned that non-smokers who vape will switch to tobacco cigarettes.
Hiqa is the first authority in the EU to examine the cost-effectiveness of e-cigarettes as an intervention to assist people in giving up smoking.
It has advised the Health Minister Simon Harris to await results of ongoing vaping trials before deciding whether to recommend e-cigarettes.
Hiqa found that almost one in three people use e-cigarettes in their attempt to stop smoking, even though there is insufficient evidence to “reliably” show they work.
E-cigarettes are not advocated by the HSE as a means of quitting because of a lack of long-term data on their safety, but it does provide behavioural support to those using e-cigarettes in their attempts to quit.
Hiqa is concerned that the widespread promotion of e-cigarettes by health professionals could have the effect of normalising nicotine consumption, or act as a “gateway” to using tobacco, for new generations of people who never smoked.
There are around 820,000 smokers in Ireland, and half of them make at least one attempt to quit each year. Around €40m is spent every year on helping people to stop smoking.
Hiqa said State investment in interventions to help people quit smoking not only works but is good value for money.
It found that varenicline was the most effective single therapy and recommended it be used alone or with nicotine patches. The prescription-only medicine reduces the urge to smoke and relieves withdrawal symptoms.
Hiqa’s director of health technology, Dr Máirín Ryan, said using varenicline, together with nicotine replacement therapy, is more than 3.5 times as effective as using no active medication.
However, the combination therapy would add €7m to the annual cost of providing smoking interventions.
The study found that e-cigarettes and using varenicline, either alone or in combination with nicotine replacement therapy, were the most cost-effective strategies.
Hiqa said pregnant women who smoke should be given counselling to help them stop.
Vape Business Ireland said the report points to the “many positives” for the 29% of adult smokers who choose to vape as an alternative to smoking.
The group’s spokesman, Alan Buckley, responded to Hiqa’s concern about vaping being a gateway to smoking.
He said: “The department’s Healthy Ireland survey shows that 99.9% of vapers are ex-smokers, so we remain unclear where this concern comes from as the report does not in itself provide any research or even anecdotal evidence to back this up.”
Minister of state for health promotion Marcella Corcoran Kennedy said they have a responsibility to ensure smokers who want to quit are provided with the best chance of success.