A new study published in this month's issue of Mayo Clinic Proceedings casts doubt on the effectiveness of over-the-counter NRT for smoking cessation.
(See: Kotz D, Brown J, West R. Prospective cohort study of the effectiveness of smoking cessation treatments used in the "real world." Mayo Clinic Proceedings 2014; 89:1360-1367.)
The study - a prospective cohort study of 1560 adult smokers who were surveyed at baseline and 6 month follow-up and made at least one quit attempt between the two interviews - compared the quit rates for the use of prescription medication with specialist behavioral support, prescription medication with brief advice from their physician, over-the-counter NRT, and none of these (no use of medication).
The main outcome measure was sustained abstinence from the last quit attempt to the time of the survey. The analysis controlled for demographic variables as well as baseline level of cigarette dependence.
The results were as follows: "Compared with smokers using none of the cessation aids, the adjusted
odds of remaining abstinent up to the time of the 6-month follow-up
survey were 2.58 (95% CI, 1.48-4.52) times higher in users of
prescription medication in combination with specialist behavioral
support and 1.55 (95% CI, 1.11-2.16) times higher in users of
prescription medication with brief advice. The use of NRT bought over
the counter was associated with a lower odds of abstinence (odds ratio, 0.68; 95% CI, 0.49-0.94)."
Regarding the use of over-the-counter NRT, the study concludes: "The most frequently used form of treatment, NRT bought over the counter, appears to be associated with reduced success rates."
The Rest of the Story
This study adds to the growing evidence that while NRT is more effective than placebo in clinical trials, the real-life use of NRT is not necessarily associated with improved cessation outcomes. In this study, the researchers found that the use of over-the-counter NRT was actually associated with lower smoking cessation rates than quit attempts that did not involve the use of any medication.
The authors suggest that the reason for the failure of over-the-counter NRT in real life, but its effectiveness in clinical trials, is most likely the fact that in the clinical trials, there is intensive intervention outside of the drug, including instructions on how to use the medication, multiple study visits to help maintain adherence with medication use and the quit attempt, and consistent, long-term monitoring. As the authors argue: "This is a different situation from the real-world setting of our study in which smokers use the medication in an uncontrolled yet more realistic fashion."
The authors note that these findings are consistent with their earlier study, in which "NRT bought over the counter was equally associated with the success of
quitting than not using treatment ... (adjusted odds
ratio, 0.96; 95% CI, 0.81-1.13)."
Another possible reason why NRT is effective in clinical trials but may not be nearly as effective in real-life settings is that the clinical trials are not truly blinded. Many subjects receiving placebo are immediately aware that they are not receiving nicotine replacement and have a higher tendency to quickly give up on their quit attempt in frustration that they were assigned to the placebo arm of the study.
While the study did find a benefit of prescribed smoking cessation medication, especially in combination with specialist behavioral intervention, the reality remains that the most common form of NRT usage is over-the-counter purchase outside the setting of intensive behavioral intervention or physician advice and guidance. Thus, the "real world" effectiveness of NRT is brought into serious question by the results of this study.
In the context of their previous study showing that "real life" use of electronic cigarettes is associated with enhanced smoking cessation rates compared to the use of NRT, it appears that the existing evidence from survey studies suggests that electronic cigarettes may actually be more effective than NRT in real-life circumstances (i.e., outside the context of clinical trials).
I believe that what is needed urgently are randomized behavioral studies that directly compare electronic cigarettes head-to-head against over-the-counter NRT.
Disclosure: I have not received any funding or compensation from
the tobacco, electronic cigarette, or pharmaceutical industries.
However, I am seeking funding from several electronic cigarette
companies to conduct a behavioral study on the effects of electronic
cigarettes on smoking behavior.