March 15, 2023

Doctors have been the foremost advocates for stopping tobacco use and its associated health risks. However, in many cases, doctors are unaware of the best way to wean smokers away from cigarettes.

PRI has been awarded a Grant from the Foundation for a Smoke-Free World, Inc., a Section 501(c)3 not-for-profit organization. That Grant allowed PRI to engage Dr. Cheryl Olson, a former member of the Harvard Medical faculty, to present an opinion on the value of vaping as a harm reduction technique. Dr. Olson’s opinion can be seen on the Harm Reduction module of this website.

It may be that the electronic cigarette is the most disruptive and effective technology yet seen with respect to smoking but one that the public health community has, not only, failed to endorse but has, in most instances, actively opposed. Recently, however, certain members of the public health community have come to the realization that vaping is a most effective tool in ending cigarette smoking. There is no reason for the perfect to be an enemy of the good.

The contents, selection and presentation of facts, as well as any opinions expressed herein, are those of Dr. Olson and under no circumstances shall be regarded as reflections of the Foundation for a Smoke-Free World, Inc.  As a follow-up to her recent opinion, Dr. Olson has continued her research on the vaping issue and that research follows.

– Joseph (Jay) A. Schwartz III

President, Physicians Research Institute


With “High Certainty,” E-Cigarettes Can Ease Patients Off Cigarettes

By Cheryl K. Olson, MPH, Sc.D.


  • People who smoke are more likely to quit with vaping than with nicotine patches and gums.
  • This “high certainty evidence” comes from an independent Cochrane systematic review of 78 studies.
  • All studies found a clinically important benefit from using nicotine e-cigarettes.
  • Serious adverse events were rare, and similar for e-cigarettes and NRT.

There is now “high certainty evidence” that vaping works better than nicotine replacement therapies (NRT) to help patients who smoke. So says a recent update of the internationally respected Cochrane Collaboration’s systematic review, Electronic Cigarettes for Smoking Cessation[i].

“Our new review found the strongest evidence yet that e-cigarettes with nicotine help people to quit smoking better than traditional nicotine replacement therapies, such as patches and chewing gums,” says lead author Jamie Hartmann-Boyce.

The review’s dozen authors are affiliated with respected institutions such as the University of Oxford and Harvard Medical School. Quitting was defined as stopping smoking for at least six months.

The updated systematic review included 78 studies with over 22,000 people who smoked. Most studies were “gold standard” controlled trials and cross-over trials, with patients randomized to e-cigarettes or a control condition.  The rest were uncontrolled intervention studies with everyone assigned to vape. Quit rates could potentially be higher among people who freely choose to try e-cigarettes.

Cochrane took the unusual step of making this a “living” systematic review, to revise as new evidence comes in about e-cigarette effects and safety.  What’s coming in future updates?

“More evidence, particularly about the effect of newer e-cigarettes with better nicotine delivery than earlier ones, is needed to assist more people quit smoking,” says Hartmann-Boyce. “Longer-term data is also needed.”

We also know relatively little about effects of e-cigarette flavors and options. There’s preliminary evidence from Cochrane that people who vape to quit smoking find it helpful to switch between flavors.[ii]

Q&A: Cochrane Findings

Why vape to quit smoking? As the full Cochrane review’s introduction says, multiple factors support tobacco dependence. A cessation product that eases nicotine withdrawal symptoms and also mimics “the rituals and sensations that accompany smoking” might have an edge.

Exactly how well did vaping work? For every 100 patients randomly assigned to use e-cigarettes, 9 to 14 stopped smoking for at least six months. By comparison, six in 100 patients assigned to NRT quit smoking (as did 4 in 100 patients who used no quitting aids). For those who like the math: e-cigarette users were 1.6 times more likely to have quit than NRT users (RR 1.63; 99% CI 1.30 to 2.04).

Is it safe to vape to quit smoking? The most-mentioned unwanted effects were throat and mouth irritation, headache, cough, and feeling sick. These got better with time. Serious adverse events were rare among all groups in these studies, about two per 100.  With moderate certainty, rates of problems were about the same for e-cigarette users and NRT users.

More information for busy physicians:

What does “high certainty evidence” mean? How Cochrane works

Headquartered in the U.K., Cochrane is an international nonprofit and independent network of researchers who carry out systematic reviews of evidence. The goal is to help doctors make everyday treatment decisions. Cochrane’s website states that they “do not accept commercial or conflicted funding.”

“Electronic Cigarettes for Smoking Cessation” is what’s called an intervention review, intended to assess effectiveness and/or safety of a treatment or procedure. Because it’s also a living review, researchers scan monthly for new studies that fit their criteria, and publish full updates as warranted.

Cochrane reviews come with an evidence quality grade: this study got the highest possible grade.

[i] Hartmann-Boyce J, Lindson N, Butler AR, McRobbie H, Bullen C, et al. Electronic cigarettes for smoking cessation. Cochrane Database of Systematic Reviews, 17 November 2022.

[ii] Lindson N, Butler AR, Liber A, Levy DT, Barnett P et al. An exploration of flavors in studies of e-cigarettes for smoking cessation: secondary analyses of a systematic review with meta-analyses. Addiction 2022; 1-12. DOI: 10.1111/add.16091

[iii] Warner KE, Benowitz NL, McNeill A, Rigotti NA. Nicotine e-cigarettes as a tool for smoking cessation. Nature Medicine Feb. 2023,

Continue Reading

Become a member.

See how medical professionals and societies can join the conversation.