Interventions to increase adherence to medications for tobacco dependence

Effectiveness of smoking cessation interventions among adults: an overview of systematic reviews

BACKGROUND

This overview of reviews aims to identify evidence on the benefits (i.e. tobacco use abstinence and reduction in smoking frequency) and harms (i.e. possible adverse events/outcomes) of smoking cessation interventions among adults aged 18 years and older.

METHODS

We searched Medline, Embase, PsycINFO, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, the CADTH Health Technology Assessment Database and several other websites for grey literature. Searches were conducted on November 12, 2018, updated on September 24, 2020, with publication years 2008 to 2020. Two reviewers independently performed title-abstract and full-text screening considering pre-determined inclusion criteria. Data extraction and quality assessments were initially completed by two reviewers independently (i.e. 73% of included studies (n = 22)) using A Measurement Tool to Assess Systematic Reviews-2 (AMSTAR 2), and the remainder done by one reviewer and verified by another due to resources and feasibility. The application of Grading of Recommendations Assessment, Development and Evaluation (GRADE) was performed by one independent reviewer and verified by another.

RESULTS

A total of 22 Cochrane systematic reviews evaluating the impact of smoking cessation interventions on outcomes such as tobacco use abstinence, reduction in smoking frequency, quality of life and possible adverse events were included. Pharmaceutical (i.e. varenicline, cytisine, nicotine replacement therapy (NRT), bupropion) and behavioural interventions (i.e. physician advice, non-tailored print-based self-help materials, stage-based individual counselling, etc.) showed to have increased smoking cessation; whereas, data for mobile phone-based interventions including text messaging, hypnotherapy, acupuncture, continuous auricular stimulation, laser therapy, electrostimulation, acupressure, St John's wort, S-adenosyl-L-methionine (SAMe), interactive voice response systems and other combination treatments were unclear. Considering harms related to smoking cessation interventions, small/mild harms (i.e. increased palpitations, chest pain, nausea, insomnia, headache) were observed following NRT, varenicline and cytisine use. There were no data on harms related to behavioural therapies (i.e. individual or group counselling self-help materials, internet interventions), combination therapies or other therapies (i.e. laser therapy, electrostimulation, acupressure, St John's wort, SAMe).

CONCLUSION

Results suggest that pharmacological and behavioural interventions may help the general smoking population quit smoking with observed small/mild harms following NRT or varenicline. Consequently, evidence regarding ideal intervention strategies and the long-term impact of these interventions for preventing smoking was unclear.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018099691.

Tobacco quitlines: Opportunities for innovation to increase reach and effectiveness

The largest tobacco treatment network in North America, Tobacco Quitlines are an effective population-based approach to increase tobacco cessation; however, overall reach has decreased significantly in the past decade. A new generation of innovations responsive to evolving shifts in communication preferences, supported by research, and focused on increasing the impact of services have the potential to reinvigorate this network. The goal of this narrative review was to identify opportunities for innovation in Quitline service delivery, synthesize evidence for these opportunities, and identify gaps in the research. Innovation was defined as significant shift in current practice by utilizing novel theoretical concepts, approaches, methodologies, or interventions. The Experimental Medicine Approach informed the identification of gaps in the research. The specific domains were selected by reviewing previous reviews, commentaries, calls for action, and a recent report on promising practices. Evidence was garnered primarily from systematic reviews. Opportunities included automated and interactive digital therapeutics, novel health communications for stigma-free media campaigns, methods to increase access to nicotine replacement therapies, novel treatment options and combinations, and methods to promote engagement with digital therapeutics. Research topics that cross multiple domains include the consideration of theoretical frameworks, the identification of therapeutic targets and mechanisms of action, and the development of adapted approaches to address specific challenges and cultural responsivity. Finally, an examination is needed to understand how to improve the speed with which innovations are developed and implemented in this network.

In vivo Experience With NRT to Increase Adherence and Smoking Abstinence Among Individuals in the Criminal Legal System: Study Protocol for a Randomized Clinical Trial

BACKGROUND

While tobacco use among individuals involved in the criminal legal system remains 3-4 times higher than the general population, few interventions have been targeted for this population to aid in smoking cessation. Nicotine replacement therapy (NRT) is a relatively effective and accessible smoking cessation aid; however, individuals frequently stop use of NRT early due to side effects and misperceptions about the products. The present study aims to address low medication adherence by examining the efficacy of an "in vivo" NRT sampling experience in individuals under community criminal legal supervision.

METHODS

Following recruitment through community legal outlets, participants (N = 517) are randomized to either an "in vivo NRT sampling" group or a standard smoking cessation behavioral counseling group. The in vivo group uses NRT in session and discusses perceptions and experiences of using NRT in real time while the standard smoking cessation counseling group receives four sessions of standard behavioral smoking cessation counseling. Both groups receive four intervention sessions and 12 weeks of NRT following the intervention. The 6-month post-intervention primary outcome measures are smoking point-prevalence abstinence and medication adherence.

CONCLUSION

This is a novel smoking cessation intervention specifically aimed at increasing NRT adherence and smoking cessation among those involved in the criminal legal system, a group of individuals with high smoking rates and low rates of pharmacotherapy use. If proven effective, the present treatment could be a novel intervention to implement in criminal legal settings given the minimal requirement of resources and training.This trial is registered with www.clinicaltrials.gov-NCT02938403.

Effect of varenicline directly observed therapy versus varenicline self-administered therapy on varenicline adherence and smoking cessation in methadone-maintained smokers: a randomized controlled trial

BACKGROUND AND AIMS

Level of adherence to tobacco cessation medication regimens is believed to be causally related to medication effectiveness. This study aimed to evaluate the efficacy of varenicline directly observed therapy (DOT) on varenicline adherence and smoking cessation rates among smokers with opioid use disorder (OUD) receiving methadone treatment.

DESIGN

Multicenter, parallel-group two-arm randomized controlled trial.

SETTING

Urban opioid treatment program (OTP) in the Bronx, New York, USA.

PARTICIPANTS

Daily smokers of ≥ 5 cigarettes/day, interested in quitting (ladder of change score 6-8), in methadone treatment for ≥ 3 months, attending OTP ≥ 3 days/week. Participants' mean age was 49 years, 56% were male, 44% Latino, 30% Black, and they smoked a median of 10 cigarettes/day.

INTERVENTIONS

Individual, block, random assignment to 12 weeks of varenicline, either directly observed with methadone (DOT, n = 50) or via unsupervised self-administered treatment (SAT, n = 50).

MEASUREMENTS

The primary outcome was adherence measured by pill count. The secondary outcome was 7-day point prevalence tobacco abstinence verified by expired carbon monoxide (CO) < 8 parts per million.

FINDINGS

Retention at 24 weeks was 92%. Mean adherence was 78.5% [95% confidence interval (CI) = 71.8-85.2%] in the DOT group versus 61.8% in the SAT group (95% CI = 55.0-68.6%); differences were driven by DOT effects in the first 6 weeks. CO-verified abstinence did not differ between groups during the intervention (P = 0.26), but was higher in the DOT than the SAT group at intervention end (DOT = 18% versus SAT = 10%, difference = 8%, 95% CI = -13, 28); this difference was not significant (P = 0.39) and was not sustained at 24-week follow-up.

CONCLUSIONS

Among daily smokers attending opioid treatment programs, opioid treatment program-based varenicline directly observed therapy was associated with early increases in varenicline adherence compared with self-administered treatment, but findings were inconclusive as to whether directly observed therapy was associated with a difference in tobacco abstinence.

Quitting Failure and Success With and Without Using Medication: Latent Classes of Abstinence and Adherence to Nicotine Monotherapy, Combination Therapy, and Varenicline

INTRODUCTION

Nonadherence to pharmacotherapies complicates studies of comparative pharmacotherapy effectiveness. Modeling adherence and abstinence simultaneously may facilitate analysis of both treatment acceptability and effectiveness.

METHODS

Secondary analyses of a three-arm randomized comparative trial of nicotine patch, varenicline, and combination nicotine patch and lozenge among adult daily smokers (N = 1086) were conducted. Adherence rates collected via interactive voice response systems during the first 27 days of quitting were compared across treatment conditions. Repeated measures latent class analyses of adherence and abstinence in 3-day parcels through 27 days of a quit attempt were conducted with treatment, demographic, and smoking history covariates.

RESULTS

Adherence varied across treatments and was lowest for nicotine lozenge use in combination nicotine replacement therapy (NRT). Five latent classes that differed significantly in 6-month abstinence rates were retained, including three subgroups of adherent participants varying in treatment response and two nonadherent groups varying in abstinence probabilities. Nonadherence was more likely among those receiving varenicline and combination NRT, relative to patch monotherapy. Varenicline and combination NRT did not promote abstinence among adherent latent classes but did promote abstinence among those partially adherent, relative to patch alone. Combination therapy attenuated increased risk of treatment disengagement with more years smoking. Minority smokers, those high in dependence, and those with shorter past abstinence were at increased risk for low-adherence and low-abstinence latent classes.

CONCLUSIONS

Varenicline and combination nicotine patch and lozenge are less likely to be used as directed and may not increase first-month abstinence better than patch alone when taken adherently.

IMPLICATIONS

This secondary analysis of adherence and abstinence in a comparative effectiveness trial shows that adherence is highest for the nicotine patch, next highest for varenicline, and lowest for combination nicotine patch and lozenge therapy due to low lozenge use. Distinct latent classes were found that varied in both first-month abstinence and adherence. Varenicline and combination NRT may not enhance abstinence over patch alone among smokers who take medication adherently. Adherent use of medication especially benefits those who are low in dependence and have positive quitting histories; it is less beneficial to at-risk smokers and members of racial minorities.

Achieving Smoking Cessation Among Persons with Opioid Use Disorder

While prevalence of tobacco use in the US general population is declining, prevalence among those with opioid use disorder (OUD) remains high and results in excessive tobacco-related disease and premature mortality. Among smokers with OUD, tobacco cessation rates are negligible without treatment. However, both low-intensity behavioral interventions and more intensive motivational interventions yield negligible cessation rates. While contingency management has potent short-term cessation effects, effects are not maintained at post-intervention follow-up. Evidence-based smoking cessation pharmacotherapies, such as nicotine replacement therapy, bupropion, and varenicline, result in very modest cessation rates among smokers with OUD. Intensification of pharmacotherapy, such as high-dose and combination nicotine replacement therapy or extended medication treatment, has failed to improve cessation outcomes compared with standard treatment regimens. Targeting the unique challenges faced by smokers with OUD, including nicotine-opioid interactions and poor medication adherence, has potential to improve cessation outcomes, but further research is needed to optimize intervention efficacy among smokers with OUD.

Treatment adherence and short-term outcomes of smoking cessation outpatient clinic patients

INTRODUCTION

Previous studies have shown that adherence to treatment is fundamental to success in smoking cessation. However, smoking cessation medication regimens are limited significantly by the struggle to adhere to them. This study was conducted to evaluate the factors associated with treatment adherence and quitting success in a group of patients that applied to our smoking cessation outpatient clinic (SCC).

METHODS

Patients that applied to SCC between April 2015 and December 2016 who were evaluated, found suitable for smoking cessation interventions and started pharmacological treatment were included in this study. Only those who could be reached by phone three months after their first application became participants. Those who had used the prescribed treatment for at least 30 days were grouped as treatment-adherent.

RESULTS

In total, data for 346 patients were evaluated. Mean (±SD) age was 44.3±13.9 years; most of them were male (63%), primary school graduated (36.1%), self-employed (43.7%), and had no comorbid diseases (71%). Bupropion was started in 52% of the patients, that rate was 35.8% for varenicline and 12.1% for a combination of the nicotine patch and gum. Mean days for treatment use was 20.9±18.5; 59% of the patients were non-adherent to their treatment and 51.7% had only one control visit number. Adverse reactions due to treatment were recorded in 25% of participants, and at their third month 37.9% of them had quit smoking. In multivariate logistic regression analysis, increase in control visit number, absence of adverse reaction, and varenicline use, were each associated with higher treatment adherence (p<0.001) and only being in the treatment-adherent group was associated with quit success (OR=3.01, 95% CI: 1.88–4.81, p=0.001).

CONCLUSIONS

This study showed that most patients did not use their prescribed SC treatments adequately; a main factor that affects quit success is treatment adherence. There is a need for closer monitoring and follow-up to ensure adequate use of treatment of patients.

Interventions to increase adherence to medications for tobacco dependence

BACKGROUND

Pharmacological treatments for tobacco dependence, such as nicotine replacement therapy (NRT), have been shown to be safe and effective interventions for smoking cessation. Higher levels of adherence to these medications increase the likelihood of sustained smoking cessation, but many smokers use them at a lower dose and for less time than is optimal. It is important to determine the effectiveness of interventions designed specifically to increase medication adherence. Such interventions may address motivation to use medication, such as influencing beliefs about the value of taking medications, or provide support to overcome problems with maintaining adherence.

OBJECTIVES

To assess the effectiveness of interventions aiming to increase adherence to medications for smoking cessation on medication adherence and smoking abstinence compared with a control group typically receiving standard care.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialized Register, and clinical trial registries (ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform) to the 3 September 2018. We also conducted forward and backward citation searches.

SELECTION CRITERIA

Randomised, cluster-randomised or quasi-randomised studies in which adults using active pharmacological treatment for smoking cessation were allocated to an intervention arm where there was a principal focus on increasing adherence to medications for tobacco dependence, or a control arm providing standard care. Dependent on setting, standard care may have comprised minimal support or varying degrees of behavioural support. Included studies used a measure that allowed assessment of the degree of medication adherence.

DATA COLLECTION AND ANALYSIS

Two authors independently screened studies for eligibility, extracted data for included studies and assessed risk of bias. For continuous outcome measures, we calculated effect sizes as standardised mean differences (SMDs). For dichotomous outcome measures, we calculated effect sizes as risk ratios (RRs). In meta-analyses for adherence outcomes, we combined dichotomous and continuous data using the generic inverse variance method and reported pooled effect sizes as SMDs; for abstinence outcomes, we reported and pooled dichotomous outcomes. We obtained pooled effect sizes with 95% confidence intervals (CIs) using random-effects models. We conducted subgroup analyses to assess whether the primary focus of the adherence treatment ('practicalities' versus 'perceptions' versus both), the delivery approach (participant versus clinician-centred) or the medication type were associated with effectiveness.

MAIN RESULTS

We identified two new studies, giving a total of 10 studies, involving 3655 participants. The medication adherence interventions studied were all provided in addition to standard behavioural support.They typically provided further information on the rationale for, and emphasised the importance of, adherence to medication or supported the development of strategies to overcome problems with maintaining adherence (or both). Seven studies targeted adherence to NRT, two to bupropion and one to varenicline. Most studies were judged to be at high or unclear risk of bias, with four of these studies judged at high risk of attrition or detection bias. Only one study was judged to be at low risk of bias.Meta-analysis of all 10 included studies (12 comparisons) provided moderate-certainty evidence that adherence interventions led to small improvements in adherence (i.e. the mean amount of medication consumed; SMD 0.10, 95% CI 0.03 to 0.18; I² = 6%; n = 3655), limited by risk of bias. Subgroup analyses for the primary outcome identified no significant subgroup effects, with effect sizes for subgroups imprecisely estimated. However, there was a very weak indication that interventions focused on the 'practicalities' of adhering to treatment (i.e. capabilities, resources, levels of support or skills) may be effective (SMD 0.21, 95% CI 0.03 to 0.38; I² = 39%; n = 1752), whereas interventions focused on treatment 'perceptions' (i.e. beliefs, cognitions, concerns and preferences; SMD 0.10, 95% CI -0.03 to 0.24; I² = 0%; n = 839) or on both (SMD 0.04, 95% CI -0.08 to 0.16; I² = 0%; n = 1064), may not be effective. Participant-centred interventions may be effective (SMD 0.12, 95% CI 0.02 to 0.23; I² = 20%; n = 2791), whereas those that are clinician-centred may not (SMD 0.09, 95% CI -0.05 to 0.23; I² = 0%; n = 864).Five studies assessed short-term smoking abstinence (five comparisons), while an overlapping set of five studies (seven comparisons) assessed long-term smoking abstinence of six months or more. Meta-analyses resulted in low-certainty evidence that adherence interventions may slightly increase short-term smoking cessation rates (RR 1.08, 95% CI 0.96 to 1.21; I² = 0%; n = 1795) and long-term smoking cessation rates (RR 1.16, 95% CI 0.96 to 1.40; I² = 48%; n = 3593). In both cases, the evidence was limited by risk of bias and imprecision, with CIs encompassing minimal harm as well as moderate benefit, and a high likelihood that further evidence will change the estimate of the effect. There was no evidence that interventions to increase adherence to medication led to any adverse events. Studies did not report on factors plausibly associated with increases in adherence, such as self-efficacy, understanding of and attitudes toward treatment, and motivation and intentions to quit.

AUTHORS' CONCLUSIONS

In people who are stopping smoking and receiving behavioural support, there is moderate-certainty evidence that enhanced behavioural support focusing on adherence to smoking cessation medications can modestly improve adherence. There is only low-certainty evidence that this may slightly improve the likelihood of cessation in the shorter or longer-term. Interventions to increase adherence can aim to address the practicalities of taking medication, change perceptions about medication, such as reasons to take it or concerns about doing so, or both. However, there is currently insufficient evidence to confirm which approach is more effective. There is no evidence on whether such interventions are effective for people who are stopping smoking without standard behavioural support.

Mining User-Generated Content in an Online Smoking Cessation Community to Identify Smoking Status: A Machine Learning Approach

Online smoking cessation communities help hundreds of thousands of smokers quit smoking and stay abstinent each year. Content shared by users of such communities may contain important information that could enable more effective and personally tailored cessation treatment recommendations. This study demonstrates a novel approach to determine individuals' smoking status by applying machine learning techniques to classify user-generated content in an online cessation community. Study data were from BecomeAnEX.org, a large, online smoking cessation community. We extracted three types of novel features from a post: domain-specific features, author-based features, and thread-based features. These features helped to improve the smoking status identification (quit vs. not) performance by 9.7% compared to using only text features of a post's content. In other words, knowledge from domain experts, data regarding the post author's patterns of online engagement, and other community member reactions to the post can help to determine the focal post author's smoking status, over and above the actual content of a focal post. We demonstrated that machine learning methods can be applied to user-generated data from online cessation communities to validly and reliably discern important user characteristics, which could aid decision support on intervention tailoring.

"If I'd Known …"-a Theory-Informed Systematic Analysis of Missed Opportunities in Optimising Use of Nicotine Replacement Therapy and Accessing Relevant Support: a Qualitative Study

Purpose

Nicotine replacement therapy (NRT) is often used suboptimally by smokers. Previous research has focused on cognitions and attitudes as potential reasons. This study drew on theoretical frameworks of behaviour to comprehensively explore smokers’ NRT use to identify new intervention targets.

Methods

Semi-structured face-to-face interviews were conducted with 16 adult UK-based smokers and ex-smokers who used NRT in recent quit attempts (mean (SD) age = 34.9(10.3); 82.3% women). The COM-B (capability, opportunity, motivation, behaviour) model and the theoretical domains framework informed the interviews and analyses. Data were analysed in NVivo 11.

Results

Two related behaviours were identified relevant to NRT use: use of NRT per se and engaging with information and support with NRT use. A meta-theme of “missed opportunity” identified instances when smokers did not or could not engage in these behaviours. For use of NRT per se, these included limited knowledge, poor technique of use, low motivation to optimise use, and lack of role models. For engaging with information and support, they included low awareness of optimal use techniques, selective information-seeking, low expectations, limited exposure to guidelines, deficient advice from healthcare professionals, and suboptimal product display. Prior suboptimal experience tended to negatively affect subsequent use and views. Participants were interested in accessible and comprehensive guidelines on NRT and its use.

Conclusions

There appear to be important missed opportunities for optimal use of NRT both in terms of use itself and engagement with information on optimal use. These missed opportunities arise from a range of capability, motivational, and opportunity-related factors.

Electronic supplementary material

The online version of this article (10.1007/s12529-018-9735-y) contains supplementary material, which is available to authorized users.

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.

Predicting smoking abstinence with biological and self-report measures of adherence to varenicline: Impact on pharmacogenetic trial outcomes

INTRODUCTION

Adherence to pharmacotherapies for tobacco dependence, such as varenicline, is necessary for effective treatment. The relationship between varenicline adherence, determined by commonly used indirect (i.e., self-reported pill counts) and infrequently used direct (i.e., varenicline levels) methods, and abstinence outcomes have not been previously examined, nor has their impact on the outcomes of a genetically randomized clinical trial been assessed.

METHODS

At Week 1 following target quit date, self-reported pill count and salivary varenicline levels were obtained from participants (N = 376) in a smoking cessation clinical trial (NCT01314001). Point-prevalence abstinence was biochemically-verified by salivary cotinine at Week 1 and by exhaled carbon monoxide at Week 1, end-of-treatment, 6 and 12 months following treatment. Blood nicotine metabolite ratio (NMR) was obtained at baseline.

RESULTS

Adherent individuals based on varenicline levels were significantly more likely to be abstinent than non-adherent individuals at Week 1 (odds ratios [ORs] 1.92-3.16, p's≤0.006), end-of-treatment (OR = 2.53, p = .004), and six months following treatment (OR = 2.30, p = .03). In contrast, pill counts did not consistently predict abstinence. Including direct measures of adherence enhanced the association between rate of nicotine metabolism (NMR) and end-of-treatment abstinence; normal metabolizers (NMR ≥ 0.31) were significantly more likely than slow metabolizers (NMR < 0.31) to be abstinent at end-of-treatment (OR = 2.00, p = .005).

CONCLUSION

Adherence based on salivary varenicline, rather than on pill counts, is predictive of Week 1 abstinence, irrespective of the biomarker of abstinence assessed, and of long-term abstinence. Direct measures of adherence enhance the ability to assess the impact of a biomarker or genetic marker on abstinence outcomes.

Factors associated with smoking cessation success in Lebanon

Objective:

The objective is to assess factors associated with the success rate of smoking cessation among Lebanese smokers in a smoking cessation center.

Methods:

A cross-sectional data study, conducted between March 2014 and March 2016 in an outpatient smoking cessation center with 156 enrolled patients. The patient’s nicotine dependence and motivation to quit smoking were evaluated according to the Fagerstrom Test for Nicotine Dependence and Richmond tests respectively.

Results:

The number of packs smoked per year decreased the odds of smoking cessation success (p=0.004, ORa=0.982, CI 0.97-0.994), while the compliance with the offered treatment increased the odds of success by 7.68 times (p<0.001, ORa=7.68, CI 3.438-17.187). Highly dependent and highly motivated smokers had more success in the quitting process compared to those with a lower dependence and motivation respectively.

Conclusion:

Our findings showed that many factors can influence smoking cessation, an experience described as difficult, most significantly the number of packs per year and compliance with the smoking cessation treatment. Moreover, although these outcomes are not representative of the entire Lebanese population, we believe that health authorities could utilize these results when implementing upcoming smoking cessations programs. All attempts at cessation should have a goal of reducing the number of packs smoked per year to improve the chances of ceasing into the future.

Factors Associated with Adherence to Transdermal Nicotine Patches within a Smoking Cessation Effectiveness Trial

BACKGROUND

Adherence to transdermal nicotine patches, one of the most popular and effective treatment for nicotine dependence, remains very low and is a strong predictor of cessation rates. This study examined individual factors related to adherence as well as differences over time between adherent (≥ 80% of daily patch use) and non-adherent participants (< 80% of daily patch use).

METHODS

We analyzed data from 440 participants who received 8 weeks of 21mg transdermal nicotine and 4 behavioral counseling sessions within an effectiveness trial that examined the effects of long-term treatment. Multiple logistical regression assessed baseline variables associated with patch adherence and generalized estimating equations (GEE) were used to evaluate changes in craving and withdrawal, depressive and anxiety symptoms, substitute and complementary reinforcers, and side effects between participants who were or were not adherent.

RESULTS

In a logistic regression model, being female, living with a child or children, and higher self-reported anxiety symptoms were predictive of lower patch adherence (p < .05). In the GEE analysis, adherence was significantly associated with: a greater reduction in craving, a greater engagement in substitute reinforcers, and a greater decrease in complementary reinforcers over time (p < .05).

CONCLUSIONS

Difficulties adhering to transdermal nicotine patches may be related to psychiatric comorbidity, difficulty managing nicotine craving, and challenges with engaging in substitute reinforcers and reducing exposure to complementary reinforcers. These constructs may serve as targets for interventions designed to increase treatment adherence.

Measures and predictors of varenicline adherence in the treatment of nicotine dependence

INTRODUCTION

While adherence to medication in smoking cessation clinical trials is strongly associated with clinical outcome, very few studies have evaluated the validity of pill count as a measure of adherence relative to a biological assay, and evaluated a broad range of correlates of adherence.

METHODS

In a smoking cessation clinical trial of varenicline, we compared pill counts collected over 4 different time periods to varenicline salivary levels taken after 2weeks of treatment, as well as evaluated predictors of adherence to varenicline.

RESULTS

Using a binary measure of adherence based on salivary varenicline levels, adherence was higher among older, white, and more educated participants. Relative to 3, 7, and 14-day pill count, 12-week pill count was the only significant measure able to discriminate adherence as defined by salivary varenicline levels (assessed by area under the receiver operating characteristic curve; AUC=0.59, p=0.004). Seventy-two percent of participants who indicated adherence on 12-week pill count were classified as adherent based on varenicline saliva levels (sensitivity=0.80; specificity=0.40). There was modest variability in the relationship between 12-week pill count and varenicline levels across race and rate of nicotine metabolism. Lastly, General Estimating Equation models demonstrated that longitudinal changes in withdrawal, craving, negative and positive affect, and side effect count and severity were not related to adherence based on salivary varenicline levels.

CONCLUSIONS

These results indicate that 12-week pill count was the best, albeit a relatively weak, measure of varenicline adherence; additional factors associated with treatment adherence need to be identified.

Success rates in smoking cessation: Psychological preparation plays a critical role and interacts with other factors such as psychoactive substances

INTRODUCTION

The aim of this study was to identify factors associated with the results of smoking cessation attempts.

METHODS

Data were collected in Clermont-Ferrand from a smoking cessation clinic between 1999 and 2009 (1,361 patients). Smoking cessation was considered a success when patients were abstinent 6 months after the beginning of cessation. Multivariate logistic regression was used to investigate the association between abstinence and different factors.

RESULTS

The significant factors were a history of depression (ORadjusted = 0.57, p = 0.003), state of depression at the initial consultation (ORa = 0.64, p = 0.005), other psychoactive substances (ORa = 0.52, p<0.0001), heart, lung and Ear-Nose-Throat diseases (ORa = 0.65, p = 0.005), age (ORa = 1.04, p<0.0001), the Richmond test (p<0.0001; when the patient's motivation went from insufficient to moderate, the frequency of abstinence was twice as high) and the Prochaska algorithm (p<0.0001; when the patient went from the 'pre-contemplation' to the 'contemplation' level, the frequency of success was four times higher). A high score in the Richmond test had a greater impact on success with increasing age (significant interaction: p = 0.01). In exclusive smokers, the contemplation level in the Prochaska algorithm was enough to obtain a satisfactory abstinence rate (65.5%) whereas among consumers of other psychoactive substances, it was necessary to reach the preparation level in the Prochaska algorithm to achieve a success rate greater than 50% (significant interaction: p = 0.02).

CONCLUSION

The psychological preparation of the smoker plays a critical role. The management of smoking cessation must be personalized, especially for consumers of other psychoactive substances and/or smokers with a history of depression.

Effect of 0.5 mg versus 1 mg varenicline for smoking cessation: a randomized controlled trial

AIMS

Varenicline is used in smoking cessation. The aims of the trial were to test for differences between standard 1- and 0.5-mg doses (both twice daily during 8 weeks) in (1) abstinence, (2) adherence and (3) side effects.

DESIGN

Open-label randomized parallel-group controlled trial with 1-year follow-up. All those randomized were included in the final sample using an intention-to-treat (ITT) approach.

SETTING

Stop-Smoking Clinic of the Virgen Macarena University Hospital in Seville, Spain.

PARTICIPANTS

The study comprised smokers (n = 484), 59.5% of whom were men with a mean age of 50.67 years and a smoking history of 37.5 pack-years.

INTERVENTION AND COMPARATOR

Participants were randomized to 1 mg (n = 245) versus 0.5 mg (n = 239) and received behavioural support, which consisted of a baseline visit and six follow-ups during 1 year.

MEASUREMENTS

The primary outcome was continuous self-reported abstinence during 1 year, with biochemical verification. The secondary outcomes were adherence and side effects. Also measured were baseline demographics, medical history and smoking characteristics.

FINDINGS

Abstinence rates at 1 year were 46.5% with 1 mg versus 46.4% with 0.5 mg [odds ratio (OR) = 0.997; 95% confidence interval (CI) = 0.7-1.43; P = 1.0]; Bayes factor in favour of H0 = 238.507, Bayes factor against H0 = 0.004. Treatment adherence was similar in both regimens (OR = 1.16; 95% CI = 0.8-1.7; P = 0.44). Side effects were reported in 19.3% of cases with 1 mg versus 12.1% with 0.5 mg, although with no significant differences between regimens (OR = 1.73; 95% CI = 0.94-3.18; P = 0.093).

CONCLUSIONS

There appears to be no difference in smoking cessation effectiveness between 1 mg and 0.5 mg varenicline, both administered twice daily for 8 weeks, with similar rates of abstinence (46.5% versus 46.4%), adherence and side effects.

Combining Text Messaging and Telephone Counseling to Increase Varenicline Adherence and Smoking Abstinence Among Cigarette Smokers Living with HIV: A Randomized Controlled Study

Smoking represents an important health risk for people living with HIV (PLHIV). Low adherence to smoking cessation pharmacotherapy may limit treatment effectiveness. In this study, 158 participants recruited from three HIV care centers in New York City were randomized to receive 12-weeks of varenicline (Chantix) either alone as standard care (SC) or in combination with text message (TM) support or TM plus cell phone-delivered adherence-focused motivational and behavioral therapy (ABT). Generalized linear mixed-effect models found a significant decline in varenicline adherence from week 1-12 across treatment groups. At 12-weeks, the probability of smoking abstinence was significantly higher in SC+TM+ABT than in SC. The study demonstrates the feasibility of delivering adherence-focused interventions to PLHIV who smoke. Findings suggest intensive behavioral support is an important component of an effective smoking cessation intervention for this population, and a focus on improving adherence self-efficacy may lead to more consistent adherence and higher smoking abstinence.

Efficacy of a universal smoking cessation intervention initiated in inpatient psychiatry and continued post-discharge: A randomised controlled trial

OBJECTIVE

Interventions are required to redress the disproportionate tobacco-related health burden experienced by persons with a mental illness. This study aimed to assess the efficacy of a universal smoking cessation intervention initiated within an acute psychiatric inpatient setting and continued post-discharge in reducing smoking prevalence and increasing quitting behaviours.

METHOD

A randomised controlled trial was undertaken across four psychiatric inpatient facilities in Australia. Participants ( N = 754) were randomised to receive either usual care ( n = 375) or an intervention comprising a brief motivational interview and self-help material while in hospital, followed by a 4-month pharmacological and psychosocial intervention ( n = 379) upon discharge. Primary outcomes assessed at 6 and 12 months post-discharge were 7-day point prevalence and 1-month prolonged smoking abstinence. A number of secondary smoking-related outcomes were also assessed. Subgroup analyses were conducted based on psychiatric diagnosis, baseline readiness to quit and nicotine dependence.

RESULTS

Seven-day point prevalence abstinence was higher for intervention participants (15.8%) than controls (9.3%) at 6 months post-discharge (odds ratio = 1.07, p = 0.04), but not at 12 months (13.4% and 10.0%, respectively; odds ratio = 1.03, p = 0.25). Significant intervention effects were not found on measures of prolonged abstinence at either 6 or 12 months post-discharge. Differential intervention effects for the primary outcomes were not detected for any subgroups. At both 6 and 12 months post-discharge, intervention group participants were significantly more likely to smoke fewer cigarettes per day, have reduced cigarette consumption by ⩾50% and to have made at least one quit attempt, relative to controls.

CONCLUSIONS

Universal smoking cessation treatment initiated in inpatient psychiatry and continued post-discharge was efficacious in increasing 7-day point prevalence smoking cessation rates and related quitting behaviours at 6 months post-discharge, with sustained effects on quitting behaviour at 12 months. Further research is required to identify strategies for achieving longer term smoking cessation.

Psychosocial interventions for supporting women to stop smoking in pregnancy

BACKGROUND

Tobacco smoking remains one of the few preventable factors associated with complications in pregnancy, and has serious long-term implications for women and babies. Smoking in pregnancy is decreasing in high-income countries, but is strongly associated with poverty and is increasing in low- to middle-income countries.

OBJECTIVES

To assess the effects of smoking cessation interventions during pregnancy on smoking behaviour and perinatal health outcomes.

SEARCH METHODS

In this sixth update, we searched the Cochrane Pregnancy and Childbirth Group's Trials Register (13 November 2015), checked reference lists of retrieved studies and contacted trial authors.

SELECTION CRITERIA

Randomised controlled trials, cluster-randomised trials, and quasi-randomised controlled trials of psychosocial smoking cessation interventions during pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and trial quality, and extracted data. Direct comparisons were conducted in RevMan, with meta-regression conducted in STATA 14.

MAIN RESULTS

The overall quality of evidence was moderate to high, with reductions in confidence due to imprecision and heterogeneity for some outcomes. One hundred and two trials with 120 intervention arms (studies) were included, with 88 trials (involving over 28,000 women) providing data on smoking abstinence in late pregnancy. Interventions were categorised as counselling, health education, feedback, incentives, social support, exercise and dissemination.In separate comparisons, there is high-quality evidence that counselling increased smoking cessation in late pregnancy compared with usual care (30 studies; average risk ratio (RR) 1.44, 95% confidence interval (CI) 1.19 to 1.73) and less intensive interventions (18 studies; average RR 1.25, 95% CI 1.07 to 1.47). There was uncertainty whether counselling increased the chance of smoking cessation when provided as one component of a broader maternal health intervention or comparing one type of counselling with another. In studies comparing counselling and usual care (largest comparison), it was unclear whether interventions prevented smoking relapse among women who had stopped smoking spontaneously in early pregnancy. However, a clear effect was seen in smoking abstinence at zero to five months postpartum (11 studies; average RR 1.59, 95% CI 1.26 to 2.01) and 12 to 17 months (two studies, average RR 2.20, 95% CI 1.23 to 3.96), with a borderline effect at six to 11 months (six studies; average RR 1.33, 95% CI 1.00 to 1.77). In other comparisons, the effect was unclear for most secondary outcomes, but sample sizes were small.Evidence suggests a borderline effect of health education compared with usual care (five studies; average RR 1.59, 95% CI 0.99 to 2.55), but the quality was downgraded to moderate as the effect was unclear when compared with less intensive interventions (four studies; average RR 1.20, 95% CI 0.85 to 1.70), alternative interventions (one study; RR 1.88, 95% CI 0.19 to 18.60), or when smoking cessation health education was provided as one component of a broader maternal health intervention.There was evidence feedback increased smoking cessation when compared with usual care and provided in conjunction with other strategies, such as counselling (average RR 4.39, 95% CI 1.89 to 10.21), but the confidence in the quality of evidence was downgraded to moderate as this was based on only two studies and the effect was uncertain when feedback was compared to less intensive interventions (three studies; average RR 1.29, 95% CI 0.75 to 2.20).High-quality evidence suggests incentive-based interventions are effective when compared with an alternative (non-contingent incentive) intervention (four studies; RR 2.36, 95% CI 1.36 to 4.09). However pooled effects were not calculable for comparisons with usual care or less intensive interventions (substantial heterogeneity, I2 = 93%).High-quality evidence suggests the effect is unclear in social support interventions provided by peers (six studies; average RR 1.42, 95% CI 0.98 to 2.07), in a single trial of support provided by partners, or when social support for smoking cessation was provided as part of a broader intervention to improve maternal health.The effect was unclear in single interventions of exercise compared to usual care (RR 1.20, 95% CI 0.72 to 2.01) and dissemination of counselling (RR 1.63, 95% CI 0.62 to 4.32).Importantly, high-quality evidence from pooled results demonstrated that women who received psychosocial interventions had a 17% reduction in infants born with low birthweight, a significantly higher mean birthweight (mean difference (MD) 55.60 g, 95% CI 29.82 to 81.38 g higher) and a 22% reduction in neonatal intensive care admissions. However the difference in preterm births and stillbirths was unclear. There did not appear to be adverse psychological effects from the interventions.The intensity of support women received in both the intervention and comparison groups has increased over time, with higher-intensity interventions more likely to have higher-intensity comparisons, potentially explaining why no clear differences were seen with increasing intervention intensity in meta-regression analyses. Among meta-regression analyses: studies classified as having 'unclear' implementation and unequal baseline characteristics were less effective than other studies. There was no clear difference between trials implemented by researchers (efficacy studies), and those implemented by routine pregnancy staff (effectiveness studies), however there was uncertainty in the effectiveness of counselling in four dissemination trials where the focus on the intervention was at an organisational level. The pooled effects were similar in interventions provided for women classified as having predominantly low socio-economic status, compared to other women. The effect was significant in interventions among women from ethnic minority groups; however not among indigenous women. There were similar effect sizes in trials with biochemically validated smoking abstinence and those with self-reported abstinence. It was unclear whether incorporating use of self-help manuals or telephone support increased the effectiveness of interventions.

AUTHORS' CONCLUSIONS

Psychosocial interventions to support women to stop smoking in pregnancy can increase the proportion of women who stop smoking in late pregnancy and the proportion of infants born low birthweight. Counselling, feedback and incentives appear to be effective, however the characteristics and context of the interventions should be carefully considered. The effect of health education and social support is less clear. New trials have been published during the preparation of this review and will be included in the next update.

Toward precision smoking cessation treatment II: Proximal effects of smoking cessation intervention components on putative mechanisms of action

BACKGROUND

Understanding how smoking cessation treatments exert their effects can inform treatment development and use. Factorial designs allow researchers to examine whether multiple intervention components affect hypothesized change mechanisms, and whether the affected mechanisms are related to cessation.

METHODS

This is a secondary data analysis of smokers recruited during primary care visits (N=637, 55% women, 87% white) who were motivated to quit. Participants in this fractional factorial experiment were randomized to one level of each of six intervention factors: Prequit Nicotine Patch vs None, Prequit Nicotine Gum vs None, Preparation Counseling vs None, Intensive In-Person Counseling vs Minimal, Intensive Phone Counseling vs Minimal, and 16 vs 8 Weeks of Combination Nicotine Replacement (nicotine patch+nicotine gum). Data on putative mechanisms (e.g., medication use, withdrawal, self-efficacy) and smoking status were gathered using daily assessments and during follow-up assessment calls.

RESULTS

Some intervention components influenced hypothesized mechanisms. Prequit Gum and Patch each reduced prequit smoking and enhanced prequit coping and self-efficacy. In-Person Counseling increased prequit motivation to quit, postquit self-efficacy, and postquit perceived intratreatment support. Withdrawal reduction and reduced prequit smoking produced the strongest effects on cessation. The significant effect of combining Prequit Gum and In-Person Counseling on 26-week abstinence was mediated by increased prequit self-efficacy.

CONCLUSIONS

This factorial experiment identified which putative treatment mechanisms were influenced by discrete intervention components and which mechanisms influenced cessation. Such information supports the combined use of prequit nicotine gum and intensive in-person counseling as cessation interventions that operate via increased prequit self-efficacy.

Using Bayes factors for testing hypotheses about intervention effectiveness in addictions research

BACKGROUND AND AIMS

It has been proposed that more use should be made of Bayes factors in hypothesis testing in addiction research. Bayes factors are the ratios of the likelihood of a specified hypothesis (e.g. an intervention effect within a given range) to another hypothesis (e.g. no effect). They are particularly important for differentiating lack of strong evidence for an effect and evidence for lack of an effect. This paper reviewed randomized trials reported in Addiction between January and June 2013 to assess how far Bayes factors might improve the interpretation of the data.

METHODS

Seventy-five effect sizes and their standard errors were extracted from 12 trials. Seventy-three per cent (n = 55) of these were non-significant (i.e. P > 0.05). For each non-significant finding a Bayes factor was calculated using a population effect derived from previous research. In sensitivity analyses, a further two Bayes factors were calculated assuming clinically meaningful and plausible ranges around this population effect.

RESULTS

Twenty per cent (n = 11) of the non-significant Bayes factors were < ⅓ and 3.6% (n = 2) were > 3. The other 76.4% (n = 42) of Bayes factors were between ⅓ and 3. Of these, 26 were in the direction of there being an effect (Bayes factor > 1 and < 3); 12 tended to favour the hypothesis of no effect (Bayes factor < 1 and > ⅓); and for four there was no evidence either way (Bayes factor = 1). In sensitivity analyses, 13.3% of Bayes Factors were < ⅓ (n = 20), 62.7% (n = 94) were between ⅓ and 3 and 24.0% (n = 36) were > 3, showing good concordance with the main results.

CONCLUSIONS

Use of Bayes factors when analysing data from randomized trials of interventions in addiction research can provide important information that would lead to more precise conclusions than are obtained typically using currently prevailing methods.

Pilot evaluation of a brief intervention to improve nicotine patch adherence among smokers living with HIV/AIDS

Nicotine replacement therapy is an effective intervention for smoking cessation, but adherence tends to be low. This article presents results from a pilot evaluation of a brief smoking cessation treatment to improve adherence to the nicotine patch among Latino smokers living with HIV/AIDS. Forty smokers were randomized to receive either a standard 5 As counseling session and 8-week treatment of nicotine patch, or a similar intervention that added a 10-min module to the 5 As counseling that focused on improving adherence to the nicotine patch. Smoking outcomes (breath carbon monoxide monitoring verified 7-day point prevalence and continuous abstinence) were evaluated through a 3-month follow-up. Patch usage during the follow-up period was also assessed. Intention to treat analyses indicated that abstinence rates were 2 to 3 times higher in the adherence condition compared with the standard condition (7-day point prevalence abstinence: 35.0% vs. 15.0%; continuous abstinence: 30.0% vs. 10.0%). Nicotine patch compliance over an 8-week period was also higher in the adherence condition than in the standard condition (44% vs. 25%). Although this small pilot was conducted to estimate effect sizes and was not powered to detect group differences, results are promising and suggest that adding a 10-min module focused on nicotine patch adherence to a standard 5 As protocol can increase abstinence rates. Given that this smoking cessation treatment was not specifically tailored to either HIV-positive smokers or Latino smokers, future research should examine whether it may be a promising approach for improving nicotine patch adherence in the general population of smokers. (PsycINFO Database Record

Developing a nicotine patch adherence intervention for HIV-positive Latino smokers

This paper describes two phases of formative research that had the goal of developing a treatment designed to improve adherence with the nicotine patch in HIV-positive Latino smokers. Each research phase (Phase I and II) was conducted independent of the other and used different qualitative methods to inform the development of the intervention. Phase I interviewed n=14 smokers who had previous experience using the nicotine patch to gain detailed understanding of how, when, and why they used it; their perceived barriers to using it; and their perspective on ways to improve adherence to it. Phase II provided n=35 smokers with brief smoking cessation treatment and nicotine patches, then interviewed them in "near real time" over a two month period about their use of the patch during a quit attempt (e.g., perceived barriers and facilitators). Authors of the paper extracted relevant themes emerging from the interview transcripts across the two phases. Results indicated that consistent use of the nicotine patch was associated with maintaining high motivation for use (i.e., not necessarily motivation to quit, but motivation to continue patch use); linking its use with established daily routines (e.g., with taking other medications, with brushing teeth); and maintaining realistic expectations for patch efficacy (e.g., that users may still experience some level of craving and/or withdrawal). This information will used to develop and pilot test a brief treatment module that focuses on improving nicotine patch adherence.

Varenicline for smoking cessation: a narrative review of efficacy, adverse effects, use in at-risk populations, and adherence

Treating tobacco dependence is the most effective way to reduce tobacco-related death and disability. Counseling and pharmacotherapy have been shown to increase tobacco abstinence rates among smokers. Varenicline is the most effective monotherapy treatment for tobacco dependence; however, it is prescribed less often than indicated, and adherence is less than optimal. We conducted a literature review of the development, efficacy, safety, contraindications, and adverse effects of varenicline; including reviewing data regarding combination therapy, extended duration, and patient adherence. Varenicline was developed to work specifically on the factors that underlie nicotine addiction. Phase II and Phase III trials established dosing, safety profiles, and efficacy. Postmarketing research raised concerns about neuropsychiatric and cardiac effects, resulting in warning labels being added and modified to encourage discussions with patients weighing the risks and benefits. While more research is needed, evidence is strong that varenicline is safe and effective in treating tobacco dependence among people who are at higher risk for neuropsychiatric symptoms and cardiovascular disease. The effectiveness of varenicline can be improved by taking it in combination with other medications, enhancing patient adherence and extending the duration of treatment.

Comparative effectiveness of intervention components for producing long-term abstinence from smoking: a factorial screening experiment

AIMS

To identify promising intervention components that help smokers attain and maintain abstinence during a quit attempt.

DESIGN

A 2 × 2 × 2 × 2 × 2 randomized factorial experiment.

SETTING

Eleven primary care clinics in Wisconsin, USA.

PARTICIPANTS

A total of 544 smokers (59% women, 86% white) recruited during primary care visits and motivated to quit.

INTERVENTIONS

Five intervention components designed to help smokers attain and maintain abstinence: (1) extended medication (26 versus 8 weeks of nicotine patch + nicotine gum); (2) maintenance (phone) counseling versus none; (3) medication adherence counseling versus none; (4) automated (medication) adherence calls versus none; and (5) electronic medication monitoring with feedback and counseling versus electronic medication monitoring alone.

MEASUREMENTS

The primary outcome was 7-day self-reported point-prevalence abstinence 1 year after the target quit day.

FINDINGS

Only extended medication produced a main effect. Twenty-six versus 8 weeks of medication improved point-prevalence abstinence rates (43 versus 34% at 6 months; 34 versus 27% at 1 year; P = 0.01 for both). There were four interaction effects at 1 year, showing that an intervention component's effectiveness depended upon the components with which it was combined.

CONCLUSIONS

Twenty-six weeks of nicotine patch + nicotine gum (versus 8 weeks) and maintenance counseling provided by phone are promising intervention components for the cessation and maintenance phases of smoking treatment.

Additional behavioural support as an adjunct to pharmacotherapy for smoking cessation

BACKGROUND

Effective pharmacotherapies are available to help people who are trying to stop smoking, but quitting can still be difficult and providing higher levels of behavioural support may increase success rates further.

OBJECTIVES

To evaluate the effect of increasing the intensity of behavioural support for people using smoking cessation medications, and to assess whether there are different effects depending on the type of pharmacotherapy, or the amount of support in each condition.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialised Register in May 2015 for records with any mention of pharmacotherapy, including any type of nicotine replacement therapy (NRT), bupropion, nortriptyline or varenicline that evaluated the addition of personal support or compared two or more intensities of behavioural support.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials in which all participants received pharmacotherapy for smoking cessation and conditions differed by the amount of behavioural support. The intervention condition had to involve person-to-person contact. The control condition could receive less intensive personal contact, or just written information. We did not include studies that used a contact-matched control to evaluate differences between types or components of support. We excluded trials recruiting only pregnant women, trials recruiting only adolescents, and trials with less than six months follow-up.

DATA COLLECTION AND ANALYSIS

One author prescreened search results and two authors agreed inclusion or exclusion of potentially relevant trials. One author extracted data and another checked them.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) and 95% confidence interval (CI) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

Forty-seven studies met the inclusion criteria with over 18,000 participants in the relevant arms. There was little evidence of statistical heterogeneity (I² = 18%) so we pooled all studies in the main analysis. There was evidence of a small but statistically significant benefit from more intensive support (RR 1.17, 95% CI 1.11 to 1.24) for abstinence at longest follow-up. All but four of the included studies provided four or more sessions of support to the intervention group. Most trials used NRT. We did not detect significant effects for studies where the pharmacotherapy was nortriptyline (two trials) or varenicline (one trial), but this reflects the absence of evidence.In subgroup analyses, studies that provided at least four sessions of personal contact for the intervention and no personal contact for the control had slightly larger estimated effects (RR 1.25, 95% CI 1.08 to 1.45; 6 trials, 3762 participants), although a formal test for subgroup differences was not significant. Studies where all intervention counselling was via telephone (RR 1.28, 95% CI 1.17 to 1.41; 6 trials, 5311 participants) also had slightly larger effects, and the test for subgroup differences was significant, but this subgroup analysis was not prespecified. In this update, the benefit of providing additional behavioural support was similar for the subgroup of trials in which all participants, including controls, had at least 30 minutes of personal contact (RR 1.18, 95% CI 1.06 to 1.32; 21 trials, 5166 participants); previously the evidence of benefit in this subgroup had been weaker. This subgroup was not prespecified and a test for subgroup differences was not significant. We judged the quality of the evidence to be high, using the GRADE approach. We judged a small number of trials to be at high risk of bias on one or more domains, but findings were not sensitive to their exclusion.

AUTHORS' CONCLUSIONS

Providing behavioural support in person or via telephone for people using pharmacotherapy to stop smoking has a small but important effect. Increasing the amount of behavioural support is likely to increase the chance of success by about 10% to 25%, based on a pooled estimate from 47 trials. Subgroup analysis suggests that the incremental benefit from more support is similar over a range of levels of baseline support.