Cost and Effectiveness of Combination Nicotine Replacement Therapy Among Heavy Smokers Contacting a Quitline

Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation

BACKGROUND

Nicotine replacement therapy (NRT) aims to replace nicotine from cigarettes. This helps to reduce cravings and withdrawal symptoms, and ease the transition from cigarette smoking to complete abstinence. Although there is high-certainty evidence that NRT is effective for achieving long-term smoking abstinence, it is unclear whether different forms, doses, durations of treatment or timing of use impacts its effects.

OBJECTIVES

To determine the effectiveness and safety of different forms, deliveries, doses, durations and schedules of NRT, for achieving long-term smoking cessation.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning NRT in the title, abstract or keywords, most recently in April 2022.

SELECTION CRITERIA

We included randomised trials in people motivated to quit, comparing one type of NRT use with another. We excluded studies that did not assess cessation as an outcome, with follow-up of fewer than six months, and with additional intervention components not matched between arms. Separate reviews cover studies comparing NRT to control, or to other pharmacotherapies.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. We measured smoking abstinence after at least six months, using the most rigorous definition available. We extracted data on cardiac adverse events (AEs), serious adverse events (SAEs) and study withdrawals due to treatment.  MAIN RESULTS: We identified 68 completed studies with 43,327 participants, five of which are new to this update. Most completed studies recruited adults either from the community or from healthcare clinics. We judged 28 of the 68 studies to be at high risk of bias. Restricting the analysis only to those studies at low or unclear risk of bias did not significantly alter results for any comparisons apart from the preloading comparison, which tested the effect of using NRT prior to quit day whilst still smoking.  There is high-certainty evidence that combination NRT (fast-acting form plus patch) results in higher long-term quit rates than single form (risk ratio (RR) 1.27, 95% confidence interval (CI) 1.17 to 1.37; I2 = 12%; 16 studies, 12,169 participants). Moderate-certainty evidence, limited by imprecision, indicates that 42/44 mg patches are as effective as 21/22 mg (24-hour) patches (RR 1.09, 95% CI 0.93 to 1.29; I2 = 38%; 5 studies, 1655 participants), and that 21 mg patches are more effective than 14 mg (24-hour) patches (RR 1.48, 95% CI 1.06 to 2.08; 1 study, 537 participants). Moderate-certainty evidence, again limited by imprecision, also suggests a benefit of 25 mg over 15 mg (16-hour) patches, but the lower limit of the CI encompassed no difference (RR 1.19, 95% CI 1.00 to 1.41; I2 = 0%; 3 studies, 3446 participants). Nine studies tested the effect of using NRT prior to quit day (preloading) in comparison to using it from quit day onward. There was moderate-certainty evidence, limited by risk of bias, of a favourable effect of preloading on abstinence (RR 1.25, 95% CI 1.08 to 1.44; I2 = 0%; 9 studies, 4395 participants). High-certainty evidence from eight studies suggests that using either a form of fast-acting NRT or a nicotine patch results in similar long-term quit rates (RR 0.90, 95% CI 0.77 to 1.05; I2 = 0%; 8 studies, 3319 participants). We found no clear evidence of an effect of duration of nicotine patch use (low-certainty evidence); duration of combination NRT use (low- and very low-certainty evidence); or fast-acting NRT type (very low-certainty evidence). Cardiac AEs, SAEs and withdrawals due to treatment were all measured variably and infrequently across studies, resulting in low- or very low-certainty evidence for all comparisons. Most comparisons found no clear evidence of an effect on these outcomes, and rates were low overall. More withdrawals due to treatment were reported in people using nasal spray compared to patches in one study (RR 3.47, 95% CI 1.15 to 10.46; 1 study, 922 participants; very low-certainty evidence) and in people using 42/44 mg patches in comparison to 21/22 mg patches across two studies (RR 4.99, 95% CI 1.60 to 15.50; I2 = 0%; 2 studies, 544 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

There is high-certainty evidence that using combination NRT versus single-form NRT and 4 mg versus 2 mg nicotine gum can result in an increase in the chances of successfully stopping smoking. Due to imprecision, evidence was of moderate certainty for patch dose comparisons. There is some indication that the lower-dose nicotine patches and gum may be less effective than higher-dose products. Using a fast-acting form of NRT, such as gum or lozenge, resulted in similar quit rates to nicotine patches. There is moderate-certainty evidence that using NRT before quitting may improve quit rates versus using it from quit date only; however, further research is needed to ensure the robustness of this finding. Evidence for the comparative safety and tolerability of different types of NRT use is limited. New studies should ensure that AEs, SAEs and withdrawals due to treatment are reported.

The Cost-Effectiveness of Nicotine Replacement Therapy Sampling in Primary Care: a Markov Cohort Simulation Model

BACKGROUND

Pharmacotherapies remain a central focus of successful tobacco control, but uptake remains very low.

OBJECTIVE

To estimate the cost effectiveness of a primary care nicotine replacement therapy (NRT) sampling intervention.

DESIGN

A Markov cohort simulation model was constructed to conduct cost-effectiveness analyses. Clinical trial results were used to initialize the Markov model. All other model parameters were derived from the literature. The study was conducted over a lifetime horizon, from the payers' budgetary perspective.

PARTICIPANTS

Smokers with a primary care visit.

INTERVENTION

Medication sampling, which provided short, starter packets of NRT (nicotine patch and lozenge) to smokers in the primary care setting.

MAIN MEASURES

Lifetime healthcare expenditures, quality-adjusted life years, and life years.

KEY RESULTS

Medication sampling was the dominant strategy compared to standard care. Our intervention cost $75, yielding a discounted lifetime savings of $1065 in healthcare expenditures, and increased both discounted quality-adjusted life years and discounted life years by 0.01. One-way sensitivity analyses showed that medication sampling remained dominant in plausible ranges except when it failed to increase cessation relative to standard care. Probabilistic sensitivity analyses confirmed that medication sampling was dominant in 94.1% of the simulated cases, with an implementation cost of $74 (95% CI $73-$76) and discounted lifetime savings in health expenditures of $1061 (- $1106 to - $1,017), increasing quality-adjusted life years by 0.008 (0.0085-0.0093) and life years by 0.008 (0.0081-0.0089).

CONCLUSION

Medication sampling, an easily implementable, scalable and low-cost intervention to encourage smoking cessation, is cost saving and improves quality of life.

Smoking cessation medicines and e-cigarettes: a systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

Cigarette smoking is one of the leading causes of early death. Varenicline [Champix (UK), Pfizer Europe MA EEIG, Brussels, Belgium; or Chantix (USA), Pfizer Inc., Mission, KS, USA], bupropion (Zyban; GlaxoSmithKline, Brentford, UK) and nicotine replacement therapy are licensed aids for quitting smoking in the UK. Although not licensed, e-cigarettes may also be used in English smoking cessation services. Concerns have been raised about the safety of these medicines and e-cigarettes.

OBJECTIVES

To determine the clinical effectiveness, safety and cost-effectiveness of smoking cessation medicines and e-cigarettes.

DESIGN

Systematic reviews, network meta-analyses and cost-effectiveness analysis informed by the network meta-analysis results.

SETTING

Primary care practices, hospitals, clinics, universities, workplaces, nursing or residential homes.

PARTICIPANTS

Smokers aged ≥ 18 years of all ethnicities using UK-licensed smoking cessation therapies and/or e-cigarettes.

INTERVENTIONS

Varenicline, bupropion and nicotine replacement therapy as monotherapies and in combination treatments at standard, low or high dose, combination nicotine replacement therapy and e-cigarette monotherapies.

MAIN OUTCOME MEASURES

Effectiveness - continuous or sustained abstinence. Safety - serious adverse events, major adverse cardiovascular events and major adverse neuropsychiatric events.

DATA SOURCES

Ten databases, reference lists of relevant research articles and previous reviews. Searches were performed from inception until 16 March 2017 and updated on 19 February 2019.

REVIEW METHODS

Three reviewers screened the search results. Data were extracted and risk of bias was assessed by one reviewer and checked by the other reviewers. Network meta-analyses were conducted for effectiveness and safety outcomes. Cost-effectiveness was evaluated using an amended version of the Benefits of Smoking Cessation on Outcomes model.

RESULTS

Most monotherapies and combination treatments were more effective than placebo at achieving sustained abstinence. Varenicline standard plus nicotine replacement therapy standard (odds ratio 5.75, 95% credible interval 2.27 to 14.90) was ranked first for sustained abstinence, followed by e-cigarette low (odds ratio 3.22, 95% credible interval 0.97 to 12.60), although these estimates have high uncertainty. We found effect modification for counselling and dependence, with a higher proportion of smokers who received counselling achieving sustained abstinence than those who did not receive counselling, and higher odds of sustained abstinence among participants with higher average dependence scores. We found that bupropion standard increased odds of serious adverse events compared with placebo (odds ratio 1.27, 95% credible interval 1.04 to 1.58). There were no differences between interventions in terms of major adverse cardiovascular events. There was evidence of increased odds of major adverse neuropsychiatric events for smokers randomised to varenicline standard compared with those randomised to bupropion standard (odds ratio 1.43, 95% credible interval 1.02 to 2.09). There was a high level of uncertainty about the most cost-effective intervention, although all were cost-effective compared with nicotine replacement therapy low at the £20,000 per quality-adjusted life-year threshold. E-cigarette low appeared to be most cost-effective in the base case, followed by varenicline standard plus nicotine replacement therapy standard. When the impact of major adverse neuropsychiatric events was excluded, varenicline standard plus nicotine replacement therapy standard was most cost-effective, followed by varenicline low plus nicotine replacement therapy standard. When limited to licensed interventions in the UK, nicotine replacement therapy standard was most cost-effective, followed by varenicline standard.

LIMITATIONS

Comparisons between active interventions were informed almost exclusively by indirect evidence. Findings were imprecise because of the small numbers of adverse events identified.

CONCLUSIONS

Combined therapies of medicines are among the most clinically effective, safe and cost-effective treatment options for smokers. Although the combined therapy of nicotine replacement therapy and varenicline at standard doses was the most effective treatment, this is currently unlicensed for use in the UK.

FUTURE WORK

Researchers should examine the use of these treatments alongside counselling and continue investigating the long-term effectiveness and safety of e-cigarettes for smoking cessation compared with active interventions such as nicotine replacement therapy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041302.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 59. See the NIHR Journals Library website for further project information.

Smoking Treatment: A Report Card on Progress and Challenges

The impact of tobacco smoking treatment is determined by its reach into the smoking population and the effectiveness of its interventions. This review evaluates the reach and effectiveness of pharmacotherapy and psychosocial interventions for smoking. Historically, the reach of smoking treatment has been low, and therefore its impact has been limited, but new reach strategies such as digital interventions and health care system changes offer great promise. Pharmacotherapy tends to be more effective than psychosocial intervention when used clinically, and newer pharmacotherapy strategies hold great promise of further enhancing effectiveness. However, new approaches are needed to advance psychosocial interventions; progress has stagnated because research and dissemination efforts have focused too narrowly on skill training despite evidence that its core content may be inconsequential and the fact that its mechanisms are either unknown or inconsistent with supporting theory. Identifying effective psychosocial content and its mechanisms of action could greatly enhance the effectiveness of counseling, digital, and web interventions.

Cost-Effectiveness of Community-Based Tobacco Dependence Treatment Interventions: Initial Findings of a Systematic Review

Introduction

Scientific literature evaluating the cost-effectiveness of tobacco dependence treatment programs delivered in community-based settings is scant, which limits evidence-based tobacco control decisions. The aim of this review was to systematically assess the cost-effectiveness and quality of the economic evaluations of community-based tobacco dependence treatment interventions conducted as randomized controlled trials in the United States.

Methods

We searched 8 electronic databases and gray literature from their beginning to February 2018. Inclusion criteria were economic evaluations of community-based tobacco dependence treatments conducted as randomized controlled trials in the United States. Two independent researchers extracted data on study design and outcomes. Study quality was assessed by using Drummond and Jefferson’s economic evaluations checklist. Nine of 3,840 publications were eligible for inclusion. Heterogeneity precluded formal meta-analyses. We synthesized a qualitative narrative of outcomes.

Results

All 9 studies used cost-effectiveness analysis and a payer/provider/program perspective, but several study components, such as abstinence measures, were heterogeneous. Study participants were predominantly English speaking, middle aged, white, motivated to quit, and highly nicotine dependent. Overall, the economic evaluations met most of Drummond and Jefferson’s recommendations; however, some studies provided limited details. All studies had a cost per quit at or below $2,040 or an incremental cost-effectiveness ratio (ICER) at or below $3,781. When we considered biochemical verification, sensitivity analysis, and subgroups, the costs per quit were less than $2,050 or the ICERs were less than $6,800.

Conclusion

All community-based interventions included in this review were cost-effective. When economic evaluation results are extrapolated to future savings, the low cost per quit or ICER indicates that the cost-effectiveness of community-based tobacco dependence treatments is similar to the cost-effectiveness of clinic-based programs and that community-based interventions are a valuable approach to tobacco control. Additional research that more fully characterizes the cost-effectiveness of community-based tobacco dependence treatments is needed to inform future decisions in tobacco control policy.

Combined nicotine patch with gum versus nicotine patch alone in smoking cessation in Hong Kong primary care clinics: a randomised controlled trial

BACKGROUND

The prevalence of daily cigarette smoking has dropped to 10% in Hong Kong (HK) in 2017, however, smoking still kills 5700 persons per year. Studies suggest that abstinence rates are higher with combined NRT than single NRT, although local data on safety and benefits of combined NRT are lacking. The aim of this study is to compare the effectiveness of combined NRT with single NRT among HK Chinese.

METHODS

This is a one-year, two-arm, parallel randomised trial. Five hundred sixty smokers, who smoked ≥10 cigarettes/day for ≥1 year, were randomized to combined and single NRT. Combined NRT group received counseling and nicotine patch & gum. Single NRT group received counselling and nicotine patch. Primary outcome was abstinence rate measured as self-reported 7-day point prevalence with CO validated at 52 weeks. Secondary outcomes included smoking abstinence rates at 4, 12, & 26 weeks. Crude odds ratio and p-value were reported from logistic regression without adjustment; for trend analysis, adjusted odds ratio (AOR) and p-value were reported from Generalized Estimating Equation (GEE) (controlling for time). All AORs were adjusted for age, sex, baseline CO and clusters.

RESULTS

Abstinence rates at 4, 12, 26 and 52 weeks were all higher in the combined NRT group (35.8, 21.9, 16.8, 20.1%) compared with the single NRT group (28, 16.8, 11.2, 14.3%). At 4 weeks, combined NRT group was more likely to quit smoking (OR 1.43, 95% CI, 1.00 to 2.05) than the single NRT group. From GEE analysis, combined NRT group had a significantly higher abstinence rate (23.6%) than the single NRT group (17.6%) across repeated measures at all-time points. Combined NRT group was more likely to quit smoking (OR 1.43, 95% CI, 1.15 to 1.77). No significant difference in the side effect profile was detected between groups.

CONCLUSIONS

Smokers given 8 weeks of combined NRT were more likely to quit smoking at 4, 12, 26 and 52 weeks compared with single NRT. Combined NRT was as well tolerated as single NRT and it should be further promoted in our community.

TRIAL REGISTRATION

NCT03836560 from ClinicalTrial.gov , 9 Feb 2019.

Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation

BACKGROUND

Nicotine replacement therapy (NRT) aims to replace nicotine from cigarettes to ease the transition from cigarette smoking to abstinence. It works by reducing the intensity of craving and withdrawal symptoms. Although there is clear evidence that NRT used after smoking cessation is effective, it is unclear whether higher doses, longer durations of treatment, or using NRT before cessation add to its effectiveness.

OBJECTIVES

To determine the effectiveness and safety of different forms, deliveries, doses, durations and schedules of NRT, for achieving long-term smoking cessation, compared to one another.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group trials register, and trial registries for papers mentioning NRT in the title, abstract or keywords. Date of most recent search: April 2018.

SELECTION CRITERIA

Randomized trials in people motivated to quit, comparing one type of NRT use with another. We excluded trials that did not assess cessation as an outcome, with follow-up less than six months, and with additional intervention components not matched between arms. Trials comparing NRT to control, and trials comparing NRT to other pharmacotherapies, are covered elsewhere.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. Smoking abstinence was measured after at least six months, using the most rigorous definition available. We extracted data on cardiac adverse events (AEs), serious adverse events (SAEs), and study withdrawals due to treatment. We calculated the risk ratio (RR) and the 95% confidence interval (CI) for each outcome for each study, where possible. We grouped eligible studies according to the type of comparison. We carried out meta-analyses where appropriate, using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We identified 63 trials with 41,509 participants. Most recruited adults either from the community or from healthcare clinics. People enrolled in the studies typically smoked at least 15 cigarettes a day. We judged 24 of the 63 studies to be at high risk of bias, but restricting the analysis only to those studies at low or unclear risk of bias did not significantly alter results, apart from in the case of the preloading comparison. There is high-certainty evidence that combination NRT (fast-acting form + patch) results in higher long-term quit rates than single form (RR 1.25, 95% CI 1.15 to 1.36, 14 studies, 11,356 participants; I² = 4%). Moderate-certainty evidence, limited by imprecision, indicates that 42/44 mg are as effective as 21/22 mg (24-hour) patches (RR 1.09, 95% CI 0.93 to 1.29, 5 studies, 1655 participants; I² = 38%), and that 21 mg are more effective than 14 mg (24-hour) patches (RR 1.48, 95% CI 1.06 to 2.08, 1 study, 537 participants). Moderate-certainty evidence (again limited by imprecision) also suggests a benefit of 25 mg over 15 mg (16-hour) patches, but the lower limit of the CI encompassed no difference (RR 1.19, 95% CI 1.00 to 1.41, 3 studies, 3446 participants; I² = 0%). Five studies comparing 4 mg gum to 2 mg gum found a benefit of the higher dose (RR 1.43, 95% CI 1.12 to 1.83, 5 studies, 856 participants; I² = 63%); however, results of a subgroup analysis suggest that only smokers who are highly dependent may benefit. Nine studies tested the effect of using NRT prior to quit day (preloading) in comparison to using it from quit day onward; there was moderate-certainty evidence, limited by risk of bias, of a favourable effect of preloading on abstinence (RR 1.25, 95% CI 1.08 to 1.44, 9 studies, 4395 participants; I² = 0%). High-certainty evidence from eight studies suggests that using either a form of fast-acting NRT or a nicotine patch results in similar long-term quit rates (RR 0.90, 95% CI 0.77 to 1.05, 8 studies, 3319 participants; I² = 0%). We found no evidence of an effect of duration of nicotine patch use (low-certainty evidence); 16-hour versus 24-hour daily patch use; duration of combination NRT use (low- and very low-certainty evidence); tapering of patch dose versus abrupt patch cessation; fast-acting NRT type (very low-certainty evidence); duration of nicotine gum use; ad lib versus fixed dosing of fast-acting NRT; free versus purchased NRT; length of provision of free NRT; ceasing versus continuing patch use on lapse; and participant- versus clinician-selected NRT. However, in most cases these findings are based on very low- or low-certainty evidence, and are the findings from single studies.AEs, SAEs and withdrawals due to treatment were all measured variably and infrequently across studies, resulting in low- or very low-certainty evidence for all comparisons. Most comparisons found no evidence of an effect on cardiac AEs, SAEs or withdrawals. Rates of these were low overall. Significantly more withdrawals due to treatment were reported in participants using nasal spray in comparison to patch in one trial (RR 3.47, 95% CI 1.15 to 10.46, 922 participants; very low certainty) and in participants using 42/44 mg patches in comparison to 21/22 mg patches across two trials (RR 4.99, 95% CI 1.60 to 15.50, 2 studies, 544 participants; I² = 0%; low certainty).

AUTHORS' CONCLUSIONS

There is high-certainty evidence that using combination NRT versus single-form NRT, and 4 mg versus 2 mg nicotine gum, can increase the chances of successfully stopping smoking. For patch dose comparisons, evidence was of moderate certainty, due to imprecision. Twenty-one mg patches resulted in higher quit rates than 14 mg (24-hour) patches, and using 25 mg patches resulted in higher quit rates than using 15 mg (16-hour) patches, although in the latter case the CI included one. There was no clear evidence of superiority for 42/44 mg over 21/22 mg (24-hour) patches. Using a fast-acting form of NRT, such as gum or lozenge, resulted in similar quit rates to nicotine patches. There is moderate-certainty evidence that using NRT prior to quitting may improve quit rates versus using it from quit date only; however, further research is needed to ensure the robustness of this finding. Evidence for the comparative safety and tolerability of different types of NRT use is of low and very low certainty. New studies should ensure that AEs, SAEs and withdrawals due to treatment are both measured and reported.

Nicotine replacement therapy versus control for smoking cessation

BACKGROUND

Nicotine replacement therapy (NRT) aims to temporarily replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.

OBJECTIVES

To determine the effectiveness and safety of nicotine replacement therapy (NRT), including gum, transdermal patch, intranasal spray and inhaled and oral preparations, for achieving long-term smoking cessation, compared to placebo or 'no NRT' interventions.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning 'NRT' or any type of nicotine replacement therapy in the title, abstract or keywords. Date of most recent search is July 2017.

SELECTION CRITERIA

Randomized trials in people motivated to quit which compared NRT to placebo or to no treatment. We excluded trials that did not report cessation rates, and those with follow-up of less than six months, except for those in pregnancy (where less than six months, these were excluded from the main analysis). We recorded adverse events from included and excluded studies that compared NRT with placebo. Studies comparing different types, durations, and doses of NRT, and studies comparing NRT to other pharmacotherapies, are covered in separate reviews.

DATA COLLECTION AND ANALYSIS

Screening, data extraction and 'Risk of bias' assessment followed standard Cochrane methods. The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We identified 136 studies; 133 with 64,640 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The majority of studies were conducted in adults and had similar numbers of men and women. People enrolled in the studies typically smoked at least 15 cigarettes a day at the start of the studies. We judged the evidence to be of high quality; we judged most studies to be at high or unclear risk of bias but restricting the analysis to only those studies at low risk of bias did not significantly alter the result. The RR of abstinence for any form of NRT relative to control was 1.55 (95% confidence interval (CI) 1.49 to 1.61). The pooled RRs for each type were 1.49 (95% CI 1.40 to 1.60, 56 trials, 22,581 participants) for nicotine gum; 1.64 (95% CI 1.53 to 1.75, 51 trials, 25,754 participants) for nicotine patch; 1.52 (95% CI 1.32 to 1.74, 8 trials, 4439 participants) for oral tablets/lozenges; 1.90 (95% CI 1.36 to 2.67, 4 trials, 976 participants) for nicotine inhalator; and 2.02 (95% CI 1.49 to 2.73, 4 trials, 887 participants) for nicotine nasal spray. The effects were largely independent of the definition of abstinence, the intensity of additional support provided or the setting in which the NRT was offered. A subset of six trials conducted in pregnant women found a statistically significant benefit of NRT on abstinence close to the time of delivery (RR 1.32, 95% CI 1.04 to 1.69; 2129 participants); in the four trials that followed up participants post-partum the result was no longer statistically significant (RR 1.29, 95% CI 0.90 to 1.86; 1675 participants). Adverse events from using NRT were related to the type of product, and include skin irritation from patches and irritation to the inside of the mouth from gum and tablets. Attempts to quantitatively synthesize the incidence of various adverse effects were hindered by extensive variation in reporting the nature, timing and duration of symptoms. The odds ratio (OR) of chest pains or palpitations for any form of NRT relative to control was 1.88 (95% CI 1.37 to 2.57, 15 included and excluded trials, 11,074 participants). However, chest pains and palpitations were rare in both groups and serious adverse events were extremely rare.

AUTHORS' CONCLUSIONS

There is high-quality evidence that all of the licensed forms of NRT (gum, transdermal patch, nasal spray, inhalator and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50% to 60%, regardless of setting, and further research is very unlikely to change our confidence in the estimate of the effect. The relative effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT. NRT often causes minor irritation of the site through which it is administered, and in rare cases can cause non-ischaemic chest pain and palpitations.