Mailed distribution of free nicotine patches without behavioral support: Predictors of use and cessation

Evaluating the Impact of Pharmacotherapy in Augmenting Quit Rates Among Hispanic Adults in an App-Delivered Smoking Cessation Intervention: Secondary Analysis of a Randomized Controlled Trial

BACKGROUND

Hispanic adults receive less advice to quit smoking and use fewer evidence-based smoking cessation treatments compared to their non-Hispanic counterparts. Digital smoking cessation interventions, such as those delivered via smartphone apps, provide a feasible and within-reach treatment option for Hispanic adults who smoke and want to quit smoking. While the combination of pharmacotherapy and behavioral interventions are considered best practices for smoking cessation, its efficacy among Hispanic adults, especially alongside smartphone app-based interventions, is uncertain.

OBJECTIVE

This secondary analysis used data from a randomized controlled trial that compared the efficacy of 2 smoking cessation apps, iCanQuit (based on acceptance and commitment therapy) and QuitGuide (following US clinical practice guidelines), to explore the association between pharmacotherapy use and smoking cessation outcomes among the subsample of 173 Hispanic participants who reported on pharmacotherapy use. Given the randomized design, we first tested the potential interaction of pharmacotherapy use and intervention arm on 12-month cigarette smoking abstinence. We then examined whether the use of any pharmacotherapy (ie, nicotine replacement therapy [NRT], varenicline, or bupropion) and NRT alone augmented each app-based intervention efficacy.

METHODS

Participants reported using pharmacotherapy on their own during the 3-month follow-up and cigarette smoking abstinence at the 12-month follow-up via web-based surveys. These data were used (1) to test the interaction effect of using pharmacotherapy to aid smoking cessation and intervention arm (iCanQuit vs QuitGuide) on smoking cessation at 12 months and (2) to test whether the use of pharmacotherapy to aid smoking cessation augmented the efficacy of each intervention arm to help participants successfully quit smoking.

RESULTS

The subsample of Hispanic participants was recruited from 30 US states. They were on average 34.5 (SD 9.3) years of age, 50.9% (88/173) were female, and 56.1% (97/173) reported smoking at least 10 cigarettes daily. Approximately 22% (38/173) of participants reported using pharmacotherapy to aid smoking cessation at the 3-month follow-up, including NRT, varenicline, or bupropion, with no difference between intervention arms. There was an interaction between pharmacotherapy use and intervention arm that marginally influenced 12-month quit rates at 12 months (P for interaction=.053). In the iCanQuit arm, 12-month missing-as-smoking quit rates were 43.8% (7/16) for pharmacotherapy users versus 28.8% (19/16) for nonusers (odds ratio 2.21, 95% CI 0.66-7.48; P=.20). In the QuitGuide arm, quit rates were 9.1% (2/22) for pharmacotherapy users versus 21.7% (15/69) for nonusers (odds ratio 0.36, 95% CI 0.07-1.72; P=.20). Results were similar for the use of NRT only.

CONCLUSIONS

Combining pharmacotherapy to aid smoking cessation with a smartphone app-based behavioral intervention that teaches acceptance of cravings to smoke (iCanQuit) shows promise in improving quit rates among Hispanic adults. However, this combined approach was not effective with the US clinical guideline-based app (QuitGuide).

TRIAL REGISTRATION

ClinicalTrials.gov NCT02724462; https://clinicaltrials.gov/study/NCT02724462.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1001/jamainternmed.2020.4055.

Targeted distribution of nicotine patches by mail to rural regions of Canada: Predictors of patch use

INTRODUCTION

Rural regions generally report higher smoking rates than urban centers, which increases the risk of tobacco related harms and consequences, and makes promoting smoking cessation in these areas a priority. Mass distribution of nicotine replacement therapy (NRT) by postal mail has been found to increase the odds of successful cessation attempts. Understanding factors that contribute to the use of NRT could help maximize this intervention's effectiveness.

METHODS

People who smoke cigarettes and live in rural areas of Canada were recruited from December 2020 to February 2022 using random digit telephone dialing. Participants were either randomized to be mailed a free, 5-week supply of NRT patches (experimental condition; n=252) or not (control condition; n=246). This secondary analysis used data from this randomized controlled trial to conduct an ordinal regression to determine if any variables measured at baseline predicted which participants in the experimental condition used none, some, or all of the NRT patches.

RESULTS

Greater confidence in ability to quit (AOR=1.07; 95% CI: 1.00-1.15) independently predicted more patch use, while living in more remote places (AOR=0.25; 95% CI: 0.07-0.90) and past substance use (compared to having no history) (AOR=0.68; 95% CI: 0.45-1.04) independently predicted less use.

CONCLUSIONS

Understanding what contributes to NRT use in rural mass distribution programs could help maximize the odds of successful cessation attempts, personalize treatment recommendations, and target limited rural resources. Future research focused on rural NRT use and smoking cessation is merited.

Correlates of nicotine patch adherence in daily life

BACKGROUND

African Americans who smoke are disproportionately affected by the health consequences of smoking. Nicotine replacement therapy (NRT) is effective for helping people successfully quit, yet there are well-documented issues with nicotine patch adherence. This study aimed to examine the real-time associations of risk factors for patch non-adherence [lapse, motivation, self-efficacy, urge, cigarette availability] with patch adherence in a sample of African Americans who smoke and are attempting to quit.

METHODS

Participants were 239 African American adults, 50 % female, and ages 18-74. Ecological momentary assessment was used to assess patch use and risk factors. Multilevel modeling for binary outcomes was used to test concurrent and lagged associations between risk factors and patch use.

RESULTS

Lapse at a previous assessment (OR=0.61, 95 % CI: 0.42, 0.88), and urge (OR=0.77, 95 % CI: 0.66, 0.89) and cigarette availability (OR=0.84, 95 % CI: 0.71, 0.99) at concurrent assessments were associated with lower likelihood of patch use. Concurrent motivation (OR=1.28, 95 % CI: 1.05, 1.55) and self-efficacy (OR=1.31, 95 % CI: 1.06, 1.62) were associated with greater likelihood of patch use. There were no significant lagged associations between motivation, self-efficacy, urge, or cigarette availability with patch use.

DISCUSSION

It is critical to examine correlates of non-adherence among African Americans who smoke because they are less likely to quit and are disproportionately impacted by the health consequences of tobacco use. The results suggest that interventions might focus on promoting patch adherence at certain times (e.g., when cigarettes are available) and/or leveraging the benefits of protective factors (e.g., motivation and self-efficacy).

The influence of sociodemographic, tobacco use, and mental health characteristics on treatment adherence among adults enrolled in a community-based tobacco cessation program

Background

While counseling and pharmacological interventions are known to facilitate smoking cessation, poor adherence can impact their effectiveness. Therefore, this study aimed to identify personal and clinical factors that influenced adherence to smoking cessation treatment among socioeconomically disadvantaged adult Oklahomans enrolled in a publicly available tobacco treatment program and observational research study.

Methods

Adult participants (N = 442) were enrolled in a community-based tobacco treatment program. Logistic regression models identified sociodemographic, mental health, and substance use characteristics associated with treatment adherence. Adherence was measured by counseling session attendance and weeks of moderate/high medication adherence assessed via the Medication Adherence Questionnaire. Analyses were conducted using SAS 9.4 with p < 0.05.

Results

Participants (mean age of 53, 55 % female, and 42.3 % racially minoritized), smoked 16 (SD = 10) cigarettes/day for 30 years on average (SD = 15), and 44.8 % reported depression (Center for Epidemiological Studies Depression Scale [CESD] score ≥ 10). Self-efficacy, White race, increasing age, and years of smoking were positively associated with counseling adherence, while menthol use, being uninsured, and depression predicted lower counseling adherence. Medication adherence was lower among individuals who used menthol cigarettes, lived with someone who smoked, and had higher levels of expired carbon monoxide.

Conclusions

This study highlights key factors that influenced adherence to smoking cessation treatment in a socioeconomically disadvantaged population. Tailored interventions are needed to address social, behavioral, and environmental factors, such as living situations and mental health, in smoking cessation interventions to enhance treatment outcomes for underserved populations. Future tobacco cessation programs should consider these factors to improve adherence and, ultimately, success rates.

A qualitative study of attitudes and perceptions of smoking cessation medication among patients with cancer

PURPOSE

Among patients with cancer, tobacco use remains high. Nearly half who report smoking at diagnosis continue to smoke following diagnosis, and use of smoking cessation medication remains low. This study explores attitudes, barriers, and preferences for smoking cessation medication among patients enrolled in a tobacco treatment trial in the context of cancer care.

METHODS

This is a secondary qualitative analysis of the Smokefree Support Study. Of 221 participants who completed the 6-month follow-up survey, n = 72 participants were randomly selected for an exit interview. Interviews were conducted using a semi-structured interview guide, recorded, transcribed, and individually coded using NVivo 11 until high interrater reliability was reached (Kappa > 0.86).

RESULTS

Participants (55.6% female) were predominantly White (83.3%) and on average 60 years old. Many participants held negative beliefs about smoking cessation medications, primarily concerns about safety and side effects in the context of cancer treatment. Lack of understanding interactions with ongoing chemotherapy and access were the most common barriers reported by those who did not use cessation medication during the study. For those who did use medication during the study, positive outcomes included craving reduction, ease of use and access, and psychological benefits.

CONCLUSION

The findings suggest a knowledge gap in the safety and effectiveness of smoking cessation medications, specifically in relation to cancer care. Addressing this knowledge gap may increase medication uptake, adherence, and quit rates. Cancer care providers are seen as instrumental in emphasizing the importance and safety of smoking cessation medications as well as patient access concerns.

IMPLICATIONS

Tobacco use among patients with cancer remains high and has serious clinical implications. Tobacco cessation is associated with decreased treatment-related toxicity, decreased risk of second primary cancers, and increased survival rates. Smoking cessation medications are effective, yet patients with cancer have low usage rates. Elucidating reasons associated with smoking cessation medication nonadherence will assist cancer care providers in better addressing factors that increase adherence rates.

Do medications increase the efficacy of digital interventions for smoking cessation? Secondary results from the iCanQuit randomized trial

BACKGROUND AND AIMS

iCanQuit is a smartphone application (app) proven efficacious for smoking cessation in a Phase III randomized controlled trial (RCT). This study aimed to measure whether medications approved by the US Food and Drug Administration (FDA) for smoking cessation would further enhance the efficacy of iCanQuit, relative to its parent trial comparator-the National Cancer Institute's (NCI's) QuitGuide app.

DESIGN

Secondary analysis of the entire parent trial sample of a two-group (iCanQuit and QuitGuide), stratified, doubled-blind RCT.

SETTING

United States.

PARTICIPANTS

Participants who reported using an FDA-approved cessation medication on their own (n = 619) and those who reported no use of cessation medications (n = 1469).

INTERVENTIONS

Participants were randomized to receive iCanQuit app or NCI's QuitGuide app.

MEASUREMENTS

Use of FDA-approved medications was measured at 3 months post-randomization. Smoking cessation outcomes were measured at 3, 6 and 12 months. The primary outcome was 12-month self-reported 30-day point prevalence abstinence (PPA).

FINDINGS

The data retention rate at the 12-month follow-up was 94.0%. Participants were aged 38.5 years, 71.0% female, 36.6% minority race/ethnicity, 40.6% high school or less education, residing in all 50 US States and smoking 19.2 cigarettes/day. The 29.6% of all participants who used medications were more likely to choose nicotine replacement therapy (NRT; 78.8%) than other cessation medications (i.e. varenicline or bupropion; 18.3 and 10.5%, respectively) and use did not differ by app treatment assignment (all P > 0.05). There was a significant (P = 0.049) interaction between medication use and app treatment assignment on PPA. Specifically, 12-month quit rates were 34% for iCanQuit versus 20% for QuitGuide [odds ratio (OR) = 2.36, 95% confidence interval (CI) = 1.59, 3.49] among participants reporting any medication use, whereas among participants reporting no medication use, quit rates were 28% for iCanQuit versus 22% for QuitGuide (OR = 1.41, 95% CI = 1.09, 1.82). Results were stronger for those using only NRT: 40% quit rates for iCanQuit versus 18% quit rates for QuitGuide (OR = 3.57, 95% CI = 2.20, 5.79).

CONCLUSIONS

The iCanQuit smartphone app for smoking cessation was more efficacious than the QuitGuide smartphone app, regardless of whether participants used medications to aid cessation. Smoking cessation medications, especially nicotine replacement therapy, might enhance the efficacy of the iCanQuit app.

Understanding Hesitation to Use Nicotine Replacement Therapy: A Content Analysis of Posts in Online Tobacco-Cessation Support Groups

PURPOSE

We aimed to better understand hesitancy to use nicotine replacement therapy (NRT) to quit smoking.

DESIGN

We content coded and analyzed NRT-related posts in online quit smoking support groups to understand NRT-use hesitancy and to examine associations with health outcomes.

SETTING

NRT posts were analyzed in unmoderated social-media support groups with free NRT.

SAMPLE

Adults who smoked daily (n = 438) and posted about NRT were studied, 339 of whom reported on NRT usage and 403 reported on smoking abstinence.

MEASURES

Surveys at 1-month post-quit date assessed NRT usage and smoking abstinence.

ANALYSIS

Relationships among NRT posts, NRT usage and smoking abstinence were analyzed using GEE models accounting for support group and covariates.

RESULTS

Nearly all (96.17%) participants reported using the study-provided NRT once, most (70.21%) used NRT during the past week, but less than half (45.72%) used NRT daily for the full month as recommended. Nearly two-thirds (65.34%) of NRT posts were negative. Posts reflecting dislike or no longer needing NRT were associated with a lower likelihood of using NRT in the past week at least once (B = -.66, P = .005 and B = -.37, P = .045), use occasions (B = -1.86, P = .018 and B = -1.10, P = .016) and used daily for full month (B = -.56, P = .044 and B = -.53, P = .009). Posts related to the effectiveness of NRT related to past-week NRT used at least once (B = .15, P = .023), used daily for full month (B = .25, P = .001), and smoking abstinence (B = .27, P = .002).

CONCLUSION

Strategies are needed to address dislike of NRT and strengthen perceptions of NRT efficacy, especially on social media where posts may be amplified.

Predictors of Adherence to Smoking Cessation Medications among Current and Ex-Smokers in Australia: Findings from a National Cross-Sectional Survey

Background: Adherence to smoking cessation medications (SCMs) improve the rate of successful quitting. This study aimed to evaluate the level of adherence to SCMs and associated factors among smokers and ex-smokers in Australia. Method: A cross-sectional study using an online survey was conducted in Australia. Descriptive statistics were used to present the overall characteristics of participants. Cross-tabulation with Pearson’s chi-square test was performed to evaluate the possible associations between factors. To explore barriers and facilitators of adherence to SCMs, logistic regressions were conducted. Results: Among 201 participants, 57 (28.4%) were found to be adherent to SCMs. The odds of being adherent were found to be higher among participants with good social support (AOR = 3.28, 95% CI of 2.30–6.27). Participants who did not experience anxiety symptoms had higher odds of being adherent to SCMs as compared to smokers who had anxiety symptoms (AOR = 4.41, 95% CI of 3.64–14.68). Having previous experience of using SCMs improved adherence four-fold (AOR = 3.87, 95% CI of 1.11–13.44). Level of nicotine dependence showed a direct association with adherence (AOR = 3.53, 95% CI of 1.40–8.95). Not relapsing while on the medications improved adherence (AOR = 2.88, 95% CI of 1.21–6.88). Conclusion: In a study of smokers and ex-smokers in Australia, the self-reported level of adherence to SCMs was found to be low. Adherence was associated with social, psychological, and medication-related factors. Smoking cessation interventions are recommended to include strategies that can address medication adherence.

Barriers and Facilitators of Adherence to Nicotine Replacement Therapy: A Systematic Review and Analysis Using the Capability, Opportunity, Motivation, and Behaviour (COM-B) Model

BACKGROUND

Poor adherence to nicotine replacement therapy (NRT) is associated with low rates of smoking cessation. Hence, this study aims to identify and map patient-related factors associated with adherence to NRT using the capability, opportunity, motivation, and behaviour (COM-B) model.

METHODS

A systematic review was conducted by searching five databases (MEDLINE, Scopus, EMBASE, CINAHL, and PsycINFO) and grey literature on 30 August 2020. Data were extracted, thematically analysed, and mapped to the COM-B model. The Joanna Briggs Institute (JBI) critical appraisal tool was utilised to assess the quality of studies.

RESULTS

A total of 2929 citations were screened, and 26 articles with a total of 13,429 participants included. Thirty-one factors were identified and mapped to COM-B model: psychological capability (forgetfulness, education), physical capability (level of nicotine dependence, withdrawal symptoms), reflective motivation (perception about NRT and quitting), automatic motivation (alcohol use, stress, depression), physical opportunity (cost), and social opportunity (social support). The most prominent element associated with adherence was reflective motivation followed by physical capability and automatic motivation.

CONCLUSIONS

Multiple personal, social, and environmental factors affect NRT adherence. Hence, it is recommended to implement a multifaceted behavioural intervention incorporating factors categorised under the COM-B model, which is the hub of the behaviour change wheel (BCW) to improve adherence and quitting.

Targeting mailed nicotine patch distribution interventions to rural regions of Canada: protocol for a randomized controlled trial

BACKGROUND

Quitting smoking is the most effective way of reducing the risk of cancer among smokers. One way of helping people stop smoking is to provide them with free Nicotine Replacement Therapy (NRT), such as when NRT is sent to people by postal mail as part of a mass distribution initiative. Our previous research indicated that there may be a substantial impact on increasing quit rates of a mailed NRT intervention in rural areas. The current research seeks to confirm this finding and to understand the social determinants of health driving these anticipated large effects.

METHODS/DESIGN

Telephone numbers will be randomly selected from across rural regions of Canada in order to recruit adult smokers interested in completing a smoking survey and willing to be interviewed again in 6 months. The survey will ask participants about their smoking history, demographic characteristics, and a hypothetical question: would they be interested in receiving nicotine patches if they were provided to them free of charge? Half of the smokers interested in receiving nicotine patches will be selected by chance and offered the NRT package. The other half of smokers will not be offered the nicotine patches. In addition, the municipality where each participant lives will be identified and, once the relevant general population data becomes available, attempts will be made to link participant data to relevant municipal characteristics (e.g., smoking rates, availability of health services). Characteristics of the participants and the municipalities in which they live will be used to explain why the nicotine patch intervention may have a larger impact in some rural regions compared to others.

DISCUSSION

The findings from the proposed RCT are timely and of high relevance as the distribution of nicotine patches has substantial potential to combat the public health problem of cigarette related cancer, other diseases, and premature death from tobacco use. Targeting such tobacco cessation initiatives to rural regions may substantially increase the impact of this intervention, helping to optimize the use of limited prevention resources while aiming to save the maximum number of lives.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov NCT04606797 , October, 27, 2020.

Free, easy and effective: how young adults used 8 weeks of mailed nicotine patches and to what effect

Introduction

Research shows the mass distribution of free nicotine replacement therapy (NRT) is a high-impact, population-level strategy for smoking cessation; but underrepresentation of younger, and/or lighter, smokers challenges generalisability of findings to young adult smokers.

Aims

This naturalistic study examined how and with what effect young adult smokers used free nicotine patches provided through a mass mailout programme.

Methods

In total, 5,025 eligible 18–29 year-old smokers who accessed an online ordering platform received self-help materials and an 8-week course of patches matched to their consumption level (<10 cigarettes per day (cpd); ≥10 cpd). No other behavioural support occurred. Whether participants used patches correctly and achieved 30-day continuous abstinence at 6-month follow-up were assessed.

Results

Among 694 participants with complete data: 89% used some patches; 8% used the patches correctly for 8 weeks; 31.0% (95% confidence interval (CI) = 27.6, 34.7) achieved abstinence. Adjusted logistic regression analysis showed the highest odds of abstinence was associated with the correct use of patches (odds ratio = 2.8, 95% CI = 1.5, 5.1).

Conclusions

Mass distribution of free patches may be an effective public health measure for supporting younger, lighter smokers to attempt cessation, reduce consumption, or achieve abstinence. Emphasising why and how to use NRT for the entire treatment course may enhance outcomes.

Five-Year Follow-up of a Randomized Clinical Trial Testing Mailed Nicotine Patches to Promote Tobacco Cessation

This study assesses the outcomes of nicotine patches mailed to smokers who were participants in a previous randomized clinical trial to promote tobacco cessation.

Potential for non-combustible nicotine products to reduce socioeconomic inequalities in smoking: a systematic review and synthesis of best available evidence

BACKGROUND

While some experts have emphasised the potential for e-cigarettes to facilitate cessation among smokers with low socioeconomic status (SES), there is limited evidence of their likely equity impact. We assessed the potential for electronic cigarettes and other non-combustible nicotine-containing products (NCNPs) to reduce inequalities in smoking by systematically reviewing evidence on their use by SES in countries at stage IV of the cigarette epidemic.

METHODS

Ten electronic databases were searched in February 2017 using terms relating to e-cigarettes, smokeless tobacco and nicotine replacement therapy (NRT); and SES. We included studies published since 1980 that were available in English and examined product use by SES indicators such as income and education. Data synthesis was based on those studies judged to be of medium- to high-quality using guidelines adapted from the Critical Appraisal Skills Programme.

RESULTS

We identified 54 studies describing NCNP use by SES across 12 countries, of which 27 were judged of sufficient quality to include in data synthesis. We found mixed patterns of e-cigarette current use by SES, with evidence of higher use among low-income adults but unclear or mixed findings by education and occupation. In contrast, smokeless tobacco current use was consistently higher among low SES adults. There was very limited evidence on the SES distribution of NRT in adults and of all NCNPs in young people.

CONCLUSIONS

The only NCNP for which there are clear patterns of use by SES is smokeless tobacco, where prevalence is higher among low SES groups. While this suggests a potentially positive impact on inequalities in smoking (if NCNP use displaces smoked tobacco use), this has not been seen in practice. These findings do not support the suggestion that e-cigarettes have the potential to reduce social inequalities in smoking, since i) current evidence does not show a clear trend of higher e-cigarette use in population groups with higher tobacco consumption, and ii) the experience of smokeless tobacco suggests that - even where NCNP use is higher among low SES groups - this does not necessarily replace smoked tobacco use in these groups.

Adherence to Pharmacological Smoking Cessation Interventions: A Literature Review and Synthesis of Correlates and Barriers

Introduction

Efficacious pharmacological interventions for smoking cessation are available, but poor adherence to these treatments may limit these interventions overall impact. To improve adherence to smoking cessation interventions, it is first necessary to identify and understand smoker-level characteristics that drive nonadherence (ie, nonconformance with a provider's recommendation of timing, dosage, or frequency of medication-taking during the prescribed length of time).

Methods

We present a literature review of studies examining correlates of, or self-reported reasons for, nonadherence to smoking cessation pharmacotherapies. Studies were identified through PubMed-using MeSH terms, Embase-using Emtree terms, and ISI Web of Science.

Results and Conclusions

This literature review included 50 studies that examined nonpreventable (eg, sociodemographics) and preventable (eg, forgetfulness) factors associated with adherence to smoking cessation medication and suggestions for overcoming some of the identified barriers. Systematic study of this topic would be facilitated by consistent reporting of adherence and correlates thereof in the literature, development of consistent definitions of medication adherence across studies, utilization of more objective measures of adherence (eg, blood plasma levels vs. self-report) in addition to reliance on self-reported adherence.

Implications

This article provides the most comprehensive review to date on correlates of adherence to pharmacological smoking cessation interventions. Challenges and specific gaps in the literature that should be a priority for future research are discussed. Future priorities include additional research, particularly among vulnerable populations of smokers, developing standardized definitions of adherence and methods for measuring adherence, regular assessment of cessation pharmacotherapy adherence in the context of research and clinical practice, and development of novel treatments aimed at preventable barriers to medication adherence.

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.