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Effectiveness and safety of nicotine replacement therapy assisted reduction to stop smoking: systematic review and meta-analysis

Moore D, Aveyard P, Connock M, Wang D, Fry-Smith A, Barton P . BMJ. 2009;338():b1024


OBJECTIVE: To determine the effectiveness and safety of nicotine replacement therapy assisted reduction to stop smoking. DESIGN: Systematic review of randomised controlled trials. DATA SOURCES: Cochrane Library, Medline, Embase, CINAHL, PsychINFO, Science Citation Index, registries of ongoing trials, reference lists, the drug company that sponsored most of the trials, and clinical experts. Review methods Eligible studies were published or unpublished randomised controlled trials that enrolled smokers who declared no intention to quit smoking in the short term, and compared nicotine replacement therapy (with or without motivational support) with placebo, no treatment, other pharmacological therapy, or motivational support, and reported quit rates. Two reviewers independently applied eligibility criteria. One reviewer assessed study quality and extracted data and these processes were checked by a second reviewer. The primary outcome, six months sustained abstinence from smoking beginning during treatment, was assessed by individual patient data analysis. Other outcomes were cessation and reduction at end of follow-up, and adverse events. DATA SYNTHESIS: Seven placebo controlled randomised controlled trials were included (four used nicotine replacement therapy gum, two nicotine replacement therapy inhaler, and one free choice of therapy). They were reduction studies that reported smoking cessation as a secondary outcome. The trials enrolled a total of 2767 smokers, gave nicotine replacement therapy for 6-18 months, and lasted 12-26 months. 6.75% of smokers receiving nicotine replacement therapy attained sustained abstinence for six months, twice the rate of those receiving placebo (relative risk (fixed effects) 2.06, 95% confidence interval 1.34 to 3.15; (random effects) 1.99, 1.01 to 3.91; five trials). The number needed to treat was 29. All other cessation and reduction outcomes were significantly more likely in smokers given nicotine replacement therapy than those given placebo. There were no statistically significant differences in adverse events (death, odds ratio 1.00, 95% confidence interval 0.25 to 4.02; serious adverse events, 1.16, 0.79 to 1.50; and discontinuation because of adverse events, 1.25, 0.64 to 2.51) except nausea, which was more common with nicotine replacement therapy (8.7% v 5.3%; odds ratio 1.69, 95% confidence interval 1.21 to 2.36). CONCLUSIONS: Available trials indicate that nicotine replacement therapy is an effective intervention in achieving sustained smoking abstinence for smokers who have no intention or are unable to attempt an abrupt quit. Most of the evidence, however, comes from trials with regular behavioural support and monitoring and it is unclear whether using nicotine replacement therapy without regular contact would be as effective. [References: 21]

Nicotine replacement therapy can increase sustained smoking abstinence in recalcitrant smokers

Arthur Jeske DMD, PhD; James Zahrowski DMD, MS, PharmD .


Overview

Systematic Review Conclusion

Evidence from seven randomized controlled trials concluded that nicotine replacement therapy (NRT), compared to placebo, can double the sustained smoking abstinence rate in smokers who have no intention to quit.

Critical Summary Assessment

A quantitative systematic review of good quality evidence finds NRT results in a 6 percent six-month smoking cessation rate, compared to 3 percent from placebo, in smokers who have no intention of quitting smoking.

Evidence Quality Rating

Good Evidence


Structured Abstract

Clinical Questions:

In adult smokers who have no intention of quitting, does nicotine replacement therapy (NRT) effectively and safely increase six-month smoking cessation rate?

Review Methods:

The authors included both published and unpublished randomized, placebo-controlled trials that enrolled smokers who had no intention of quitting; the trials compared NRT with placebo (with or without motivational support) and reported quit rates. Two independent reviewers assessed the eligibility of the studies. One reviewer assessed study quality and extracted data while another checked process accuracy. The primary outcome, six months of sustained smoking abstinence, was assessed by data analysis. Secondary outcomes were defined as point abstinences, sustained reduction, and defined point reduction. Adverse effects were death, hospital admission, disability, discontinuation of NRT, and nausea. Individual patient data analyses and the development of a floating 6 month abstinence outcome measure were key to produce meaningful findings. (1-3)

Main Results:

The authors selected seven controlled randomized trials (2,767 smokers) that evaluated the following types of nicotine replacement therapies: nicotine gum (4 studies), nicotine inhaler (2 studies), and free choice (1 study). In each study, participants used NRT for six-to-18 months. The duration of the studies varied between 12 and 26 months. The NRT group attained 6.75 percent sustained smoking abstinence for six months, twice the rate of those receiving placebo (relative risk [RR] = 2.06l; 95 percent confidence interval [CI] 1.34-3.15). The number needed to treat (NNT) was 29. All other cessation and reduction outcomes were significantly more likely in smokers who received NRT instead of placebo. No statistically significant differences in adverse events were reported (death, odds ratio [OR] 1.00, 95 percent CI 0.25-4.02; serious adverse events 1.16, 0.79-1.50) and discontinuation 1.25, 0.64-2.51). Nausea was more common with NRT (8.7 percent vs. 5.3 percent; OR 1.69, 95 percent CI 1.21-2.36).

Conclusion:

Nicotine replacement therapy is an effective intervention for smokers who have no intention of quitting smoking to achieve abstinence. However, the trials whose evidence supported this finding were studies in which participants also received regular behavioral support and monitoring. Thus, this review fails to makes clear which is more effective, NRT used as a sole modality or NRT supplemented with additional support and monitoring.

Source of Funding:

UK Health Technology Assessment Programme (National Institute for Health Research)UK Health Technology Assessment Programme (National Institute for Health Research)


Commentary

Importance and Context:

Smoking is one of the most preventable causes of illness and premature death. Currently, 45 million people in the U.S. smoke tobacco and 435,000 people die annually from smoking related diseases. (4) Despite 70 percent of smokers intending to stop at some time, only 12 percent are ready to stop smoking. Many smokers try to stop every year, but only 2 to 3 percent succeed. A six-month smoking cessation is important to evaluate because half of the smokers who achieve abstinence for 6 months sustain their abstinence for a lifetime. Nicotine replacement therapy is the most widely used smoking cessation aid. As a nicotine delivery system (gum, lozenges, sublingual tablets, inhaler, or dermal patches), NRT administers a lower level of nicotine than cigarettes. This reduces nicotine withdrawal symptoms, which leads to increased motivation to quit. Thus, a systematic evaluation of evidence relating to NRT is needed, regarding the outcome of sustained smoking cessation in the majority of the smoking population, which has no intention to quit.

Strengths and Weaknesses of the Systematic Review:

The authors conducted a comprehensive search of six electronic data bases from 1992 to November 2007 and used accepted methods to screen articles for inclusion. Primary outcome and secondary outcomes were defined. The authors summarized smoking data using relative risk (RR). They summarized adverse effects data using Peto odds ratio. They performed homogeneity test of the included studies.

Strengths and Weaknesses of the Evidence:

The authors selected seven high-quality randomized controlled trials, six of which were sponsored by NRT pharmaceutical companies. In most of the studies, the primary outcome in these trials was smoking reduction and not a completed six-month cessation. Study participants were heavy smokers, typically recruited by advertisement. The authors did not separate NRT from beneficial behavioral support.

Implications for Dental Practice:

This systematic review shows that in a population of smokers not ready to stop, NRT results in a 6 percent six-month cessation rate as compared to 3 percent rate for placebo. Nicotine replacement therapy also helped a significant number of participants, who otherwise would not have stopped smoking. Overall, NRT effect exerted a modest effect in smokers, with only one smoker out of a total of 29 expected to achieve sustained smoking abstinence. All forms of NRT were well tolerated without adverse effects except for slightly more nausea, likely due to a higher nicotine level in participants who continued to smoke while receiving NRT. Nicotine replacement therapy has shown a 50-70 percent increase in long-term smoking cessation in motivated, high nicotine dependent patients who did not receive behavioral support.(5) 1. Moore D, Aveyard P, Connock M, Wang D, Fry-Smith A, Barton P. Effectiveness and safety of nicotine replacement therapy assisted reduction to stop smoking: systematic review and meta-analysis. BMJ 2009;338:b1024 2. Aveyard P, Wang D, Connock M, Fry-Smith A, Barton P, Moore D. Assessing the outcomes of prolonged cessation-induction and aid-to-cessation trials: Floating prolonged abstinence. Nicotine & Tobacco Research 2009; doi: 10.1093/ntr/ntp035 3. Wang D, Connock M, Barton P, Fry-Smith A, Aveyard P, Moore D. 'Cut down to quit' with nicotine replacement therapies in smoking cessation: a systematic review of effectiveness and economic analysis. Health Technology Assessment 2008;12 4. Benowitz NL. Nicotine addiction. N Engl J Med. 2010; 362:2295-2303. 5. Stead LF, Perera R, Bullen C, Mant D, Lancaster T. Nicotine replacement therapy for smoking cessation. Cochrane Database of Systematic Reviews 2008, Issue 1. Art. No.: CD000146. DOI: 10.1002/14651858.CD000146.pub3.


Critical Summary Publication Date:

9/1/2010

These summaries are not intended to, and do not, express, imply, or summarize standards of care, but rather provide a concise reference for dentists to aid in understanding and applying evidence from the referenced systematic review in making clinically sound decisions as guided by their clinical judgment and by patient needs. American Dental Association © 2019

Other sources of nicotine may be key to kicking the smoking habit 

Arthur Jeske DMD, PhD; James Zahrowski DMD, MS, PharmD


Overview

Systematic Review Author(s)

Moore D, Aveyard P, Connock M, Wang D, Fry-Smith A, Barton P

Summary Title

Nicotine replacement therapy can increase sustained smoking abstinence in recalcitrant smokers


Summary

Body:

Placebo: (pronounced pluh-see-bo) This is a fake medicine sometimes given to people in scientific studies.  The researchers want to see if people say they feel better after taking it.  Then they can see if the real medicine helps people more than the placebo.

Smokers can quit using tobacco in a number of ways.  For example, they can just quit on the spot or "go cold turkey."  Other examples include counseling to help them change their behaviors or tobacco replacement therapy.

Tobacco replacement therapy is a way to deliver nicotine (which is the addictive chemical in tobacco) to smokers without exposing them to all the other harmful chemicals in tobacco smoke. Some examples of nicotine replacement therapy include the nicotine patch, nicotine gum, hard candies that contain nicotine or nicotine inhalers.  The authors of this systematic review wondered if people who had no plan to stop smoking would give up tobacco if treated with nicotine replacement therapy.

They looked at seven studies, involving 2,767 smokers.  The smokers had not planned to stop smoking, but they tried nicotine replacement therapy as part of the studies.  Some studies only used nicotine replacement gum others used an inhaler.  One study gave smokers a choice of which nicotine replacement therapy they would like to use.  In some of the studies smokers also recieved motivational support to encourage them to stop smoking.  All of the studies compared the nicotine replacement therapies to a placebo. 

Authors' findings
The authors found that 6 percent of smokers, who really had no plan to quit smoking, stopped using tobacco for six months after starting tobacco replacement therapy.  Only 3 percent of the smokers who  were given a placebo instead of the nicotine replacement therapy stopped using tobacco for that amount of time.  Smokers in the nicotine replacement therapy groups tended to experience nausea more often than people who took the placebo.

Conclusion
Nicotine replacement therapy seems to be a promising approach to help people stop smoking.

Questions:

Does nicotine replacement therapy help smokers, who hadn't planned to quit immediately, stop smoking?

Answer:

Yes, studies showed that providing smokers, who had no plans to quit immediately, with a source of nicotine other than tobacco seemed to help people in the studies quit smoking for at least six-months.