Effect of e-Cigarettes Plus Counseling vs Counseling Alone on Smoking Cessation: A Randomized Clinical Trial

Does e-cigarette use predict short-term smoking cessation behaviors among adults who smoke in Mexico? A longitudinal study

INTRODUCTION

This study assessed quit attempts among adults who use cigarettes either exclusively or with e-cigarettes in Mexico, where non-daily smoking predominates.

METHODS

An open cohort of Mexican adults who smoke was surveyed every four months from November 2018 to March 2021. Participants followed to the next survey were analyzed (n = 2220 individuals, 4560 observations). Multinomial logistic models regressed smoking quit attempts reported at the followup survey (ref = no attempt; tried to quit; sustained attempt of ≥30 days) on e-cigarette use frequency (none = ref; 1-2 days/week; ≥3 days/week), adjusting for sociodemographics and smoking-related variables. Additional models subdivided e-cigarette users by intentions to quit smoking in the next six months (i.e., yes/no), use of nicotine (i.e., yes/no), and vaping device used (i.e., open/closed).

RESULTS

At 4-month follow-up, 32.7 % had tried to quit, and 2.9 % had quit for 30 days or more. Compared to those who smoke exclusively, occasional, and frequent e-cigarette users were more likely to try to quit (Adjusted Relative Risk Ratio or ARRR = 1.26 and 1.66, respectively) but no more likely to sustain their quit attempt. Among those who intended to quit smoking, e-cigarette users were no more likely to either try or sustain quit attempts. Furthermore, use of e-cigarettes with nicotine (59.6 %) was unassociated with cessation except that those who frequently used e-cigarettes with nicotine were more likely to try to quit than those who smoke exclusively (ARRR = 1.88). Device type used was not differentially associated with outcomes.

CONCLUSIONS

Mexicans who smoke and use e-cigarettes appear more likely than those who smoke exclusively to try to quit but not to sustain abstinence.

e-Cigarettes, Smoking Cessation, and Weight Change: Retrospective Secondary Analysis of the Evaluating the Efficacy of e-Cigarette Use for Smoking Cessation Trial

BACKGROUND

While smoking cessation has been linked to substantial weight gain, the potential influence of e-cigarettes on weight changes among individuals who use these devices to quit smoking is not fully understood.

OBJECTIVE

This study aims to reanalyze data from the Evaluating the Efficacy of e-Cigarette Use for Smoking Cessation (E3) trial to assess the causal effects of e-cigarette use on change in body weight.

METHODS

This is a secondary analysis of the E3 trial in which participants were randomized into 3 groups: nicotine e-cigarettes plus counseling, nonnicotine e-cigarettes plus counseling, and counseling alone. With adjustment for baseline variables and the follow-up smoking abstinence status, weight changes were compared between the groups from baseline to 12 weeks' follow-up. Intention-to-treat and as-treated analyses were conducted using doubly robust estimation. Further causal analysis used 2 different propensity scoring methods to estimate causal regression curves for 4 smoking-related continuous variables. We evaluated 5 different subsets of data for each method. Selection bias was addressed, and missing data were imputed by the machine learning method extreme gradient boosting (XGBoost).

RESULTS

A total of 257 individuals with measured weight at week 12 (mean age: 52, SD 12 y; women: n=122, 47.5%) were included. Across the 3 treatment groups, of the 257 participants, 204 (79.4%) who continued to smoke had, on average, largely unchanged weight at 12 weeks, with comparable mean weight gain ranging from -0.24 kg to 0.33 kg, while 53 (20.6%) smoking-abstinent participants gained weight, with a mean weight gain ranging from 2.05 kg to 2.70 kg. After adjustment, our analyses showed that the 2 e-cigarette arms exhibited a mean gain of 0.56 kg versus the counseling alone arm. The causal regression curves analysis also showed no strong evidence supporting a causal relationship between weight gain and the 3 e-cigarette-related variables. e-Cigarettes have small and variable causal effects on weight gain associated with smoking cessation.

CONCLUSIONS

In the E3 trial, e-cigarettes seemed to have minimal effects on mitigating the weight gain observed in individuals who smoke and subsequently quit at 3 months. However, given the modest sample size and the potential underuse of e-cigarettes among those randomized to the e-cigarette treatment arms, these results need to be replicated in large, adequately powered trials.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02417467; https://www.clinicaltrials.gov/study/NCT02417467.

The potential of new nicotine and tobacco products as tools for people who smoke to quit combustible cigarettes - a systematic review of common practices and guidance towards a robust study protocol to measure cessation efficacy

New types of nicotine and tobacco products like electronic cigarettes (ECs), heated tobacco products or nicotine pouches have been discussed as less harmful alternatives to combustible cigarettes and other toxic forms of tobacco products. Their harm reduction potential lay in the efficient transition away from smoking to those new products. Numerous studies addressing the cessation efficacy of ECs have been published with contradictory outcomes. Yet, a comprehensive Cochrane review concluded with high certainty on the cessation efficacy of ECs. This prompted us to perform a review to identify weaknesses in common study designs and to summarize best practices for the study design on the potential of new nicotine products as cessation aids. 120 articles retrieved from Medline were found to be eligible. Most of the studies in the field were interventional trials while observational studies played a minor role in the evaluation of smoking cessation. Efficacy was predominantly assessed for ECs in 77% of the reports while heated tobacco (17%) and non-combustible products (11%) were less frequently investigated up to now. Measures to determine the efficacy were questionnaire-based assessments as well as use documentation/prevalence and abstinence rates. Studies varied largely in their duration and sample size with medians of 3 months and 156.5 participants, respectively.With the help of this review, we identified several weaknesses in the common study designs. One major limitation in longitudinal trials was the lack of compliance measures suited to verify the use status over longer time periods, relying solely on self-reports. Moreover, the motivation of the participants to quit was rarely defined and a profound familiarization period was not taken into account for the majority of the studies. To what extent such weaknesses influence the outcome of the studies was beyond the scope of this review. We encourage researchers to consider the recommendations which resulted from this review in order to determine the abuse liability and cessation efficacy of the products in a more robust manner. Finally, we like to call attention to the missing data for low- and middle-income countries which would require quitting strategies most urgently to combat the tobacco smoking epidemic.

Effectiveness of e-cigarettes as a stop smoking intervention in adults: a systematic review

BACKGROUND

This systematic review aims to identify the benefits and harms of electronic cigarettes (e-cigarettes) as a smoking cessation aid in adults (aged ≥ 18 years) and to inform the development of the Canadian Task Force on Preventive Health Care's (CTFPHC) clinical practice guidelines on e-cigarettes.

METHODS

We searched Ovid MEDLINE®, Ovid MEDLINE® Epub Ahead of Print, In-Process & Other Non-Indexed Citations, PsycINFO, Embase Classic + Embase, and the Cochrane Library on Wiley. Searches were conducted from January 2016 to July 2019 and updated on 24 September 2020 and 25 January 2024. Two reviewers independently performed title-abstract and full-text screening according to the pre-determined inclusion criteria. Data extraction, quality assessments, and the application of Grading of Recommendations Assessment, Development and Evaluation (GRADE) were performed by one independent reviewer and verified by another.

RESULTS

We identified 18 studies on 17 randomized controlled trials that compared e-cigarettes with nicotine to e-cigarettes without nicotine and e-cigarettes (with or without nicotine) to other interventions (i.e., no intervention, waitlist, standard/usual care, quit advice, or behavioral support). Considering the benefits of e-cigarettes in terms of smoking abstinence and smoking frequency reduction, 14 studies showed small or moderate benefits of e-cigarettes with or without nicotine compared to other interventions; although, with low, very low or moderate evidence certainty. With a focus on e-cigarettes with nicotine specifically, 12 studies showed benefits in terms of smoking abstinence when compared with usual care or non-nicotine e-cigarettes. In terms of harms following nicotine or non-nicotine e-cigarette use, 15 studies reported mild adverse events with little to no difference between groups and low to very low evidence certainty.

CONCLUSION

The evidence synthesis on the e-cigarette's effectiveness shows data surrounding benefits having low to moderate evidence certainty for some comparisons and very low certainty for others, indicating that e-cigarettes may or probably increase smoking cessation, whereas, for harms, there is low to very low evidence certainty. Since the duration for outcome measurement varied among different studies, it may not be long-term enough for Adverse Events (AEs) to emerge, and there is a need for more research to understand the long-term benefits and potential harms of e-cigarettes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018099692.

The efficacy and acceptability of pharmacological monotherapies and e-cigarette on smoking cessation: a systemic review and network meta-analysis

Background and aims

Several pharmacological interventions, such as nicotine replacement therapy (NRT), varenicline, and bupropion, have been approved for clinical use of smoking cessation. E-cigarettes (EC) are increasingly explored by many RCTs for their potentiality in smoking cessation. In addition, some RCTs are attempting to explore new drugs for smoking cessation, such as cytisine. This network meta-analysis (NMA) aims to investigate how these drugs and e-cigarettes compare regarding their efficacy and acceptability.

Materials and methods

This systematic review and NMA searched all clinical studies on smoking cessation using pharmacological monotherapies or e-cigarettes published from January 2011 to May 2022 using MEDLINE, COCHRANE Library, and PsychINFO databases. NRTs were divided into transdermal (TDN) and oronasal nicotine (ONN) by administrative routes, thus 7 network nodes were set up for direct and indirect comparison. Two different indicators measured the efficacy: prevalent and continuous smoking abstinence. The drop-out rates measured the acceptability.

Results

The final 40 clinical studies included in this study comprised 77 study cohorts and 25,889 participants. Varenicline is more effective intervention to assist in smoking cessation during 16-32 weeks follow-up, and is very likely to prompt dropout. Cytisine shows more effectiveness in continuous smoking cessation but may also lead to dropout. E-cigarettes and oronasal nicotine are more effective than no treatment in encouraging prevalent abstinence, but least likely to prompt dropout. Finally, transdermal nicotine delivery is more effective than no treatment in continuous abstinence, with neither significant effect on prevalent abstinence nor dropout rate.

Conclusion

This review suggested and agreed that Varenicline, Cytisine and transdermal nicotine delivery, as smoking cessation intervention, have advantages and disadvantages. However, we had to have reservations about e-cigarettes as a way to quit smoking in adolescents.

Electronic Nicotine-Delivery Systems for Smoking Cessation

BACKGROUND

Electronic nicotine-delivery systems - also called e-cigarettes - are used by some tobacco smokers to assist with quitting. Evidence regarding the efficacy and safety of these systems is needed.

METHODS

In this open-label, controlled trial, we randomly assigned adults who were smoking at least five tobacco cigarettes per day and who wanted to set a quit date to an intervention group, which received free e-cigarettes and e-liquids, standard-of-care smoking-cessation counseling, and optional (not free) nicotine-replacement therapy, or to a control group, which received standard counseling and a voucher, which they could use for any purpose, including nicotine-replacement therapy. The primary outcome was biochemically validated, continuous abstinence from smoking at 6 months. Secondary outcomes included participant-reported abstinence from tobacco and from any nicotine (including smoking, e-cigarettes, and nicotine-replacement therapy) at 6 months, respiratory symptoms, and serious adverse events.

RESULTS

A total of 1246 participants underwent randomization; 622 participants were assigned to the intervention group, and 624 to the control group. The percentage of participants with validated continuous abstinence from tobacco smoking was 28.9% in the intervention group and 16.3% in the control group (relative risk, 1.77; 95% confidence interval, 1.43 to 2.20). The percentage of participants who abstained from smoking in the 7 days before the 6-month visit was 59.6% in the intervention group and 38.5% in the control group, but the percentage who abstained from any nicotine use was 20.1% in the intervention group and 33.7% in the control group. Serious adverse events occurred in 25 participants (4.0%) in the intervention group and in 31 (5.0%) in the control group; adverse events occurred in 272 participants (43.7%) and 229 participants (36.7%), respectively.

CONCLUSIONS

The addition of e-cigarettes to standard smoking-cessation counseling resulted in greater abstinence from tobacco use among smokers than smoking-cessation counseling alone. (Funded by the Swiss National Science Foundation and others; ESTxENDS ClinicalTrials.gov number, NCT03589989.).

Electronic cigarettes for smoking cessation

BACKGROUND

Electronic cigarettes (ECs) are handheld electronic vaping devices which produce an aerosol by heating an e-liquid. People who smoke, healthcare providers and regulators want to know if ECs can help people quit smoking, and if they are safe to use for this purpose. This is a review update conducted as part of a living systematic review.

OBJECTIVES

To examine the safety, tolerability and effectiveness of using electronic cigarettes (ECs) to help people who smoke tobacco achieve long-term smoking abstinence, in comparison to non-nicotine EC, other smoking cessation treatments and no treatment.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialized Register to 1 February 2023, and Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 July 2023, and reference-checked and contacted study authors.

SELECTION CRITERIA

We included trials in which people who smoke were randomized to an EC or control condition. We also included uncontrolled intervention studies in which all participants received an EC intervention as these studies have the potential to provide further information on harms and longer-term use. Studies had to report an eligible outcome.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods for screening and data extraction. Critical outcomes were abstinence from smoking after at least six months, adverse events (AEs), and serious adverse events (SAEs). We used a fixed-effect Mantel-Haenszel model to calculate risk ratios (RRs) with a 95% confidence interval (CI) for dichotomous outcomes. For continuous outcomes, we calculated mean differences. Where appropriate, we pooled data in pairwise and network meta-analyses (NMA).

MAIN RESULTS

We included 88 completed studies (10 new to this update), representing 27,235 participants, of which 47 were randomized controlled trials (RCTs). Of the included studies, we rated ten (all but one contributing to our main comparisons) at low risk of bias overall, 58 at high risk overall (including all non-randomized studies), and the remainder at unclear risk. There is high certainty that nicotine EC increases quit rates compared to nicotine replacement therapy (NRT) (RR 1.59, 95% CI 1.29 to 1.93; I2 = 0%; 7 studies, 2544 participants). In absolute terms, this might translate to an additional four quitters per 100 (95% CI 2 to 6 more). There is moderate-certainty evidence (limited by imprecision) that the rate of occurrence of AEs is similar between groups (RR 1.03, 95% CI 0.91 to 1.17; I2 = 0%; 5 studies, 2052 participants). SAEs were rare, and there is insufficient evidence to determine whether rates differ between groups due to very serious imprecision (RR 1.20, 95% CI 0.90 to 1.60; I2 = 32%; 6 studies, 2761 participants; low-certainty evidence). There is moderate-certainty evidence, limited by imprecision, that nicotine EC increases quit rates compared to non-nicotine EC (RR 1.46, 95% CI 1.09 to 1.96; I2 = 4%; 6 studies, 1613 participants). In absolute terms, this might lead to an additional three quitters per 100 (95% CI 1 to 7 more). There is moderate-certainty evidence of no difference in the rate of AEs between these groups (RR 1.01, 95% CI 0.91 to 1.11; I2 = 0%; 5 studies, 1840 participants). There is insufficient evidence to determine whether rates of SAEs differ between groups, due to very serious imprecision (RR 1.00, 95% CI 0.56 to 1.79; I2 = 0%; 9 studies, 1412 participants; low-certainty evidence). Due to issues with risk of bias, there is low-certainty evidence that, compared to behavioural support only/no support, quit rates may be higher for participants randomized to nicotine EC (RR 1.88, 95% CI 1.56 to 2.25; I2 = 0%; 9 studies, 5024 participants). In absolute terms, this represents an additional four quitters per 100 (95% CI 2 to 5 more). There was some evidence that (non-serious) AEs may be more common in people randomized to nicotine EC (RR 1.22, 95% CI 1.12 to 1.32; I2 = 41%, low-certainty evidence; 4 studies, 765 participants) and, again, insufficient evidence to determine whether rates of SAEs differed between groups (RR 0.89, 95% CI 0.59 to 1.34; I2 = 23%; 10 studies, 3263 participants; very low-certainty evidence). Results from the NMA were consistent with those from pairwise meta-analyses for all critical outcomes, and there was no indication of inconsistency within the networks. Data from non-randomized studies were consistent with RCT data. The most commonly reported AEs were throat/mouth irritation, headache, cough, and nausea, which tended to dissipate with continued EC use. Very few studies reported data on other outcomes or comparisons, hence, evidence for these is limited, with CIs often encompassing both clinically significant harm and benefit.

AUTHORS' CONCLUSIONS

There is high-certainty evidence that ECs with nicotine increase quit rates compared to NRT and moderate-certainty evidence that they increase quit rates compared to ECs without nicotine. Evidence comparing nicotine EC with usual care/no treatment also suggests benefit, but is less certain due to risk of bias inherent in the study design. Confidence intervals were for the most part wide for data on AEs, SAEs and other safety markers, with no difference in AEs between nicotine and non-nicotine ECs nor between nicotine ECs and NRT. Overall incidence of SAEs was low across all study arms. We did not detect evidence of serious harm from nicotine EC, but the longest follow-up was two years and the number of studies was small. The main limitation of the evidence base remains imprecision due to the small number of RCTs, often with low event rates. Further RCTs are underway. To ensure the review continues to provide up-to-date information to decision-makers, this review is a living systematic review. We run searches monthly, with the review updated when relevant new evidence becomes available. Please refer to the Cochrane Database of Systematic Reviews for the review's current status.

Use of e-Cigarettes in Cigarette Smoking Cessation: Secondary Analysis of a Randomized Controlled Trial

BACKGROUND

Many adults use e-cigarettes to help them quit cigarette smoking. However, the impact of self-selected use of e-cigarettes on cigarette smoking cessation, particularly when concurrently receiving app-based behavioral interventions, remains unexplored.

OBJECTIVE

This study used data from a randomized trial of 2 smartphone apps to compare 12-month cigarette smoking cessation rates between participants who used e-cigarettes on their own (ie, adopters: n=465) versus those who did not (ie, nonadopters: n=1097).

METHODS

The study population included all participants who did not use e-cigarettes at baseline. "Adopters" were those who self-reported the use of e-cigarettes at either 3- or 6-month follow-ups. "Nonadopters" were those who self-reported no use of e-cigarettes at either follow-up time point. The primary cessation outcome was self-reported, complete-case, 30-day point prevalence abstinence from cigarette smoking at 12 months. Secondary outcomes were missing-as-smoking and multiple imputation analyses of the primary outcome, prolonged abstinence, and cessation of all nicotine and tobacco products at 12 months. In logistic regression models, we first examined the potential interaction between e-cigarette use and treatment arm (iCanQuit vs QuitGuide) on the primary cessation outcome. Subsequently, we compared 12-month cigarette smoking cessation rates between adopters and nonadopters separately for each app.

RESULTS

There was suggestive evidence for an interaction between e-cigarette use and treatment arm on cessation (P=.05). In the iCanQuit arm, 12-month cigarette smoking cessation rates were significantly lower among e-cigarette adopters compared with nonadopters (41/193, 21.2% vs 184/527, 34.9%; P=.003; odds ratio 0.55, 95% CI 0.37-0.81). In contrast, in the QuitGuide arm, 12-month cigarette smoking cessation rates did not differ between adopters and nonadopters (46/246, 18.7% vs 104/522, 19.9%; P=.64; odds ratio 0.91, 95% CI 0.62-1.35).

CONCLUSIONS

The use of e-cigarettes while concurrently receiving an app-based smoking cessation intervention was associated with either a lower or an unimproved likelihood of quitting cigarette smoking compared to no use. Future behavioral treatments for cigarette smoking cessation should consider including information on the potential consequences of e-cigarette use.

TRIAL REGISTRATION

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

Evaluating the impact of varying expired carbon monoxide thresholds on smoking relapse identification: insights from the E3 trial on e-cigarette efficacy for smoking cessation

OBJECTIVES

Expired carbon monoxide (ECO) is often used in smoking cessation trials to biochemically validate self-reported smoking status. The optimal ECO threshold to distinguish individuals who smoke from those who do not is debated.

DESIGN

The data from the 'Evaluating the Efficacy of E-Cigarette use for Smoking Cessation (E3) Trial' were used; the E3 trial was a randomised controlled trial that examined e-cigarettes efficacy for smoking cessation.

SETTINGS

Participants were recruited from 17 Canadian sites across 4 provinces.

PARTICIPANTS

This substudy included data from participants who returned for at least one of the clinical visits at week 4 (291), 12 (257) or 24 (218) and provided both self-reported smoking status and ECO measures. Analyses were based on 766 paired measures (ie, self-reported smoking status with corresponding ECO).

RESULTS

The ability of ECO measurements to discriminate between adults who reported smoking and those who reported abstinence varied with the threshold used. ECO thresholds of 6, 7, 8 and 9 parts per million (ppm) yielded the greatest area under the receiver operating characteristic curve (0.84). These thresholds produced sensitivities of 84%, 82%, 78% and 76% and specificities of 84%, 87%, 90% and 91%, respectively. However, at a threshold of 6 ppm, intersecting sensitivity (84%) and specificity (84%) were maximised with respect to each other. Biochemical validation had the highest agreement with self-report at an ECO threshold of 6 ppm (κ=0.57; 95% CI, 0.51 to 0.64).

CONCLUSION

The classification of participants' smoking status depends on the ECO threshold used for biochemical validation. We recommend that future smoking cessation trial investigators analyse and report the impact that varying ECO thresholds has on trial results.

TRIAL REGISTRATION NUMBER

NCT02417467.

Effect of unguided e-cigarette provision on uptake, use, and smoking cessation among adults who smoke in the USA: a naturalistic, randomised, controlled clinical trial

Background

As summarised in the most recent Cochrane review, the few clinical trials on e-cigarettes are largely focused on smoking cessation. We aimed to determine the naturalistic uptake, use, and impact of e-cigarettes among adults who may or may not want to stop smoking.

Methods

In this naturalistic, randomised, controlled clinical trial, adult smokers, across the motivational spectrum and with minimal history of e-cigarette use, were recruited online from the general community within 11 cities across the USA. Participants were randomly assigned (2:1) to either receive either a free 4-week supply of flavoured, tank-style e-cigarette, or not. E-cigarette group participants received a battery and device with up to 30 pre-filled tanks, offered among five flavours, with minimal instructions on use. The study's primary purpose was to descriptively assess naturalistic uptake and usage of the e-cigarette, and to secondarily assess its impact on smoking behavior. The latter, assessed through six months of follow-up, included: a) self-reported 7-day point prevalence abstinence, b) incidence of quit attempts, and c) smoking reduction. This trial is registered at ClinicalTrials.gov, NCT03453385.

Findings

Between 5/2018 and 3/2022, 638 adult smokers were enrolled and randomly assigned (427 in the e-cigarette group and 211 in the no-product control group). Uptake of e-cigarettes was robust: approximately 70% of participants used the product, with average usage exceeding 4 days per week during the initial 30 days. Based on an intent-to-treat approach where missing data is imputed as smoking, almost all behavioral outcomes favored the e-cigarette group relative to no-product control, including point prevalence abstinence at six months (Odds Ratio [OR] = 1.8; 95% Confidence Interval [CI] = 1.0-3.1), cumulative incidence of 24-hr quit attempts (OR = 1.5; 95% CI = 1.0-2.2), and having reduced smoking by at least 50% since baseline (OR = 1.8; 95% CI = 1.2-2.7). Results were similar under an alternative imputation.

Interpretation

Complementing cessation-focused trials, results suggest that unguided e-cigarette use also leads to smoking cessation, allaying the notion that causal effects of e-cigarettes on cessation are not reflective of real-world scenario of self-determined use. For smokers who may not be able to quit using existing pharmacologic approaches, e-cigarettes may be considered to achive that purpose.

Funding

National Cancer Institute.

Cardiopulmonary Impact of Electronic Cigarettes and Vaping Products: A Scientific Statement From the American Heart Association

Vaping and electronic cigarette (e-cigarette) use have grown exponentially in the past decade, particularly among youth and young adults. Cigarette smoking is a risk factor for both cardiovascular and pulmonary disease. Because of their more limited ingredients and the absence of combustion, e-cigarettes and vaping products are often touted as safer alternative and potential tobacco-cessation products. The outbreak of e-cigarette or vaping product use-associated lung injury in the United States in 2019, which led to >2800 hospitalizations, highlighted the risks of e-cigarettes and vaping products. Currently, all e-cigarettes are regulated as tobacco products and thus do not undergo the premarket animal and human safety studies required of a drug product or medical device. Because youth prevalence of e-cigarette and vaping product use was as high as 27.5% in high school students in 2019 in the United States, it is critical to assess the short-term and long-term health effects of these products, as well as the development of interventional and public health efforts to reduce youth use. The objectives of this scientific statement are (1) to describe and discuss e-cigarettes and vaping products use patterns among youth and adults; (2) to identify harmful and potentially harmful constituents in vaping aerosols; (3) to critically assess the molecular, animal, and clinical evidence on the acute and chronic cardiovascular and pulmonary risks of e-cigarette and vaping products use; (4) to describe the current evidence of e-cigarettes and vaping products as potential tobacco-cessation products; and (5) to summarize current public health and regulatory efforts of e-cigarettes and vaping products. It is timely, therefore, to review the short-term and especially the long-term implications of e-cigarettes and vaping products on cardiopulmonary health. Early molecular and clinical evidence suggests various acute physiological effects from electronic nicotine delivery systems, particularly those containing nicotine. Additional clinical and animal-exposure model research is critically needed as the use of these products continues to grow.

E-cigarette Price Impacts legal and Black-Market Cigarette Purchasing Under a Hypothetical Reduced-Nicotine Cigarette Standard

INTRODUCTION

The Tobacco Control Act gives the U.S. Food and Drug Administration authority to establish a reduced-nicotine content standard in combusted cigarettes. This future potential regulation may pose a significant public health benefit; however, black markets may arise to meet demand for normal-nicotine content cigarettes among smokers unwilling to transition to or use an alternative product.

AIMS AND METHODS

We determined the behavioral-economic substitutability of illicit normal-nicotine content cigarettes and e-cigarettes for reduced-nicotine content cigarettes in a hypothetical reduced-nicotine regulatory market. Adult cigarette smokers were recruited online to complete hypothetical cigarette purchasing tasks for usual-brand cigarettes, reduced-nicotine content cigarettes, and illicit normal-nicotine content cigarettes, as well as a cross-commodity task in which reduced-nicotine content cigarettes were available across multiple prices and illicit cigarettes were concurrently available for $12/pack. Participants completed two three-item cross-commodity purchasing tasks in which e-cigarettes were available for $4/pod or $12/pod alongside reduced-nicotine content cigarettes and illicit cigarettes.

RESULTS

Usual-brand cigarette purchasing was greater than illicit normal-nicotine content cigarettes and less than reduced-nicotine content cigarettes. In the cross-commodity purchasing tasks, illicit cigarettes and e-cigarettes both served as economic substitutes for reduced-nicotine content cigarettes; however, when e-cigarettes were available for $4/pod, they were purchased at greater levels than illicit cigarettes and resulted in greater reductions in reduced-nicotine content cigarettes purchasing than when available for $12/pod.

CONCLUSIONS

These data suggest that some smokers are willing to engage in illicit cigarette purchasing in a reduced-nicotine regulatory environment, but e-cigarette availability at lower prices may reduce black-market engagement and shift behavior away from combusted cigarette use.

IMPLICATIONS

E-cigarettes available at low, but not high, prices were stronger substitutes for legal, reduced-nicotine content cigarettes than illegal, normal-nicotine content cigarettes in a hypothetical reduced-nicotine tobacco market. Our findings suggest the availability of relatively inexpensive e-cigarettes may reduce illicit cigarette purchasing and combusted cigarette use under a reduced-nicotine cigarette standard.

The risk profile of electronic nicotine delivery systems, compared to traditional cigarettes, on oral disease: a review

The use of electronic nicotine delivery systems (ENDS) has exploded, especially among teenagers and new smokers, amid widespread awareness of the dangers of traditional tobacco and restrictions on smoking. However, the risk effects of ENDS on physical health, especially oral health, are still ambiguous. The purpose of this study was to review the available evidence on risks of ENDS on oral health, and compares the differences between ENDS and traditional cigarettes. For heavy smokers, transferring the addiction of tobacco to ENDS can be less harmful to periodontal condition and physical health but is not completely without risk. The components of ENDS vapor have cytotoxic, genotoxic, and carcinogenic properties, and its usage may be associated with a wide range of oral health sequelae. The chemicals in ENDS increase the susceptibility to tooth decay, increase the risk of periodontal disease, peri-implant, and oral mucosal lesions. Nicotine aerosols from ENDS can be a potential risk factor for oral cancer due to the presence of carcinogenic components. Compared to smoking traditional cigarettes, the harm associated with ENDS use may be underestimated due to the reduced ability to control vaping behavior, ease of ENDS access, fewer vaping area restrictions, and better taste. Currently, the available evidence suggests that ENDS may be a safer alternative to traditional tobacco products. Though most oral symptoms experienced by ENDS users are relatively mild and temporary compared to traditional cigarettes, the dangers of ENDS still exist. However, further research with longer follow-up periods is required to establish the long-term safety of ENDS.

Efficacy and Safety of E-Cigarette Use for Smoking Cessation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

People who smoke conventional cigarettes are increasingly turning to electronic cigarettes (e-cigarettes) as a pathway to quitting, however the efficacy and safety of e-cigarettes for smoking cessation remains controversial.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs), identified through a systematic search of the MEDLINE, EMBASE, and Cochrane CENTRAL databases. Inclusion was restricted to RCTs with a follow-up duration ≥ 6 months. The primary endpoint was the most rigorous criterion of biochemically validated abstinence at maximum follow-up, and the primary comparison was nicotine e-cigarettes versus any conventional (i.e., non-e-cigarette) smoking cessation therapy. The Cochrane Risk of Bias Tool was used to assess bias. Count data were pooled across trials using random-effects models with inverse variance weighting to estimate relative risks (RRs) and corresponding 95% confidence intervals (CIs). We registered the study protocol with the Open Science Framework Registries (osf.io/26fkq).

RESULTS

A total of 5 RCTs (n=3,253) were included. Compared with conventional smoking cessation therapies, the use of nicotine e-cigarettes was associated with an increase in abstinence, defined by the most rigorous criterion of abstinence reported (RR: 1.77; 95% CI: 1.29-2.44). Nicotine e-cigarettes also increased abstinence (defined by the most rigorous criterion) compared to non-nicotine e-cigarettes (RR: 1.56; 95% CI: 1.13-2.15). The incidence of death or SAEs was low across all trials at maximum follow-up.

CONCLUSIONS

Among individuals attempting to quit smoking, nicotine e-cigarettes are more efficacious than conventional nicotine replacement or behavioral smoking cessation therapies and may prove beneficial in reducing smoking-related health risks.

Optimal management of patients after acute coronary syndrome

Patients with clinically established atherosclerotic cardiovascular disease are at a very high risk of recurrent cardiovascular events. An adequate management of risk factors and the implementation of healthy behaviours significantly decrease the risk of unfavourable clinical outcomes and future cardiovascular events, including death. Patients discharged after an acute coronary syndrome should be managed according to their individual risk level in order to ensure the appropriate treatment. Nevertheless, care pathways should also take into consideration the available resources and the logistical/structural aspects. In this setting, cardiac rehabilitation is prosed as a multidisciplinary approach to improving daily function and reducing cardiovascular risk factors. The organization of a network with the involvement of different medical and non-medical figures is essential to ensure successful outcomes and expected cost-effectiveness.

An exploration of flavours in studies of e-cigarettes for smoking cessation: secondary analyses of a systematic review with meta-analyses

AIMS

To estimate associations between e-cigarette flavour and smoking cessation and study product use at 6 months or longer.

METHODS

Secondary analysis of data from a living systematic review, with meta-analyses and narrative synthesis, incorporating data up to January 2022. Included studies provided people who smoked combustible cigarettes with nicotine e-cigarettes for the purpose of smoking cessation compared with no treatment or other stop smoking interventions. Measurements included smoking cessation and study product use at 6 months or longer reported as risk ratios (RR) with 95% confidence intervals (CI); and flavour use at any time-points.

RESULTS

We included 16 studies (n = 10 336); 14 contributed to subgroup analyses and 10 provided participants with a choice of e-cigarette flavour. We judged nine, five and two studies at high, low and unclear risk of bias, respectively. Subgroup analyses showed no clear associations between flavour and cessation or product use. In all but one analysis, tests for subgroup differences resulted in I2 values between 0 and 35%. In the comparison between nicotine e-cigarettes and nicotine replacement therapy (NRT) (I2  = 65.2% for subgroup differences), studies offering tobacco flavour e-cigarettes showed evidence of a greater proportion of participants still using at 6 months or longer (RR = 3.81; 95% CI = 1.45-10.05; n = 1181; I2  = 84%), whereas there was little evidence for greater 6-month use when studies offered a choice of flavours (RR = 1.44; 95% CI = 0.80-2.56; n = 454; I2  = 82%). However, substantial statistical heterogeneity within subgroups makes interpretation of this result unclear. In the 10 studies where participants had a choice of flavours, and this was tracked over time, some switching between flavours occurred, but there were no clear patterns in flavour preferences.

CONCLUSIONS

There does not appear to be a clear association between e-cigarette flavours and smoking cessation or longer-term e-cigarette use, possibly due to a paucity of data. There is evidence that people using e-cigarettes to quit smoking switch between e-cigarette flavours.

E-cigarette, cannabis and combustible tobacco use: associations with xerostomia among California adolescents

OBJECTIVE

Xerostomia (subjective experience of dry mouth), while less common in younger populations, can contribute to caries and oral discomfort. Use of e-cigarettes and cannabis among adolescents is increasing and may be a xerostomia risk factor. This study evaluates xerostomia prevalence in an adolescent population, overall and by e-cigarette, cannabis and combustible tobacco use.

METHODS

Cross-sectional analyses of 12-month follow-up data (N=976; collected 2020-2021) from a cohort of adolescents recruited from public high schools in Northern California (USA) compared self-reported past 30-day e-cigarette, cannabis and other tobacco use and dry mouth (overall dry mouth experience; shortened xerostomia inventory, SXI). Dry mouth experience (never, occasionally, frequently/always) was modelled using ordered logistic regression with school-level clustering and adjustment for gender, race/ethnicity, alcohol use, asthma, physical activity and mutually for e-cigarette, cannabis and tobacco use.

RESULTS

Past 30-day use prevalence was 12% for e-cigarettes, 16% for cannabis and 3% for combustible tobacco. Occasional dry mouth experience (54%) was more common than frequent/always experience (5%). Frequent/always dry mouth was more prevalent among frequent (>5 days/month) e-cigarette (14%) and cannabis (19%) users and combustible tobacco users (19%) than non-users of those respective products (all comparisons p < 0.001). In covariable-adjusted models, frequent e-cigarette use was no longer significantly associated with dry mouth experience (OR: 1.40; 95% CI: 0.69, 2.84), while frequent cannabis use (OR: 3.17; 95% CI: 1.47, 6.82) and combustible tobacco use (OR: 1.92; 95% CI: 1.38, 2.68) were associated with greater odds of reporting more frequent dry mouth. Findings were qualitatively similar using the SXI.

CONCLUSIONS

In this study, xerostomia was not independently associated with e-cigarette use but was one potential health concern of adolescent cannabis and combustible tobacco use.

Targeting Smoking Triggers: A Nurse-led Intervention for Tobacco Smoking Cessation

Background: Nursing interventions tailored to the smoking triggers in patients with non-communicable chronic diseases are essential. However, these interventions are scant due to the nature of factors associated with smoking cessation and the poor understanding of the effect of nurse-led intervention in Iraq.Purpose: This study aimed to determine the dominant smoking triggers and examine the effects of a tailored nursing intervention on smoking behavior in patients with non-communicable chronic diseases.Methods: Convenience samples of 128 patients with non-communicable chronic diseases, male and female patients, who were 18-70 years old, were recruited in this quasi-experimental, randomized comparative trial in the outpatient clinic in one major teaching hospital in Baghdad City, Iraq. The intervention included simple yet specific instructions that were given both orally and in written form to the study samples to enable them to manage their craving to smoke for 6 weeks. The smoking triggers were assessed using Why Do You Smoke questionnaire. Participants were randomly allocated to receive either the nurse-led intervention or standard care. Data were analyzed using descriptive statistics, independent sample t-tests, logistic regression, and two-sided tests.Results: Stress reduction was the dominant smoking trigger among subjects. The percentage of participants who were either able to completely quit smoking or reduce the number of smoked cigarettes per day (n=19, 29.7%; n=28, 43.8%, respectively) was greater in the study group than those in the control group (n=5, 5.8%; n=5, 5.8%, respectively). Study findings demonstrated significant differences in the inability to improve readiness to quit smoking between the intervention group and control group (p=0.000) at the sixth-week follow-up.Conclusion: The tailored nursing intervention was effective for a successful achievement of smoking reduction and cessation among patients with non-communicable chronic diseases, and a potential to equip nurses in clinical settings to support patients to achieve this is recommended.  

Prospective association between e-cigarette use frequency patterns and cigarette smoking abstinence among adult cigarette smokers in the United States

AIMS

To estimate the association of longitudinal patterns of e-cigarette use with cigarette smoking abstinence, after accounting for time-dependent confounding and selection bias.

DESIGN

Secondary analysis of longitudinal national cohort data. Using marginal structural models and four waves of the population assessment of tobacco and health (wave 1, 2013-14; wave 2, 2014-15; wave 3, 2015-16; wave 4, 2016-18), we estimated the association of vaping frequency across waves 2 and 3 with 12-month sustained cigarette smoking abstinence at wave 4, adjusting for time-dependent confounders at waves 1 and 2 and selection bias due to drop-out with inverse probability of treatment and censoring weights.

SETTING

United States.

PARTICIPANTS/CASES

A total of 5699 adults (18+ years) who smoked cigarettes and did not vape at wave 1.

MEASUREMENTS

The exposure was vaping frequency at waves 2 and 3 (non-use, non-daily use, daily use), representing nine possible combinations of vaping frequency across two waves. Non-use at both waves was the exposure reference group. The primary outcome was sustained 12-month cigarette smoking abstinence at wave 4.

FINDINGS

Among 5699 adults who smoked cigarettes at wave 1, a total of 560 (9.8%) reported smoking abstinence at wave 4. Compared with nonuse at both waves, daily vaping at both waves [risk ratio (RR) = 3.82, 95% confidence interval (CI) = 2.59-5.64] and non-use at wave 2 followed by daily vaping at wave 3 (RR = 2.50, 95% CI = 1.66-3.77) were positively associated with smoking abstinence; non-daily vaping at both waves was inversely associated with smoking abstinence (RR = 0.28, 95% CI = 0.11-0.75). Results persisted after accounting for misclassification of e-cigarette use and cigarette smoking abstinence and after restricting to participants with plans to quit smoking.

CONCLUSIONS

In a US cohort of adult smokers, longitudinal patterns of vaping frequency appear to predict smoking abstinence, even after accounting for several sources of systematic error. Consistent daily vaping is associated with increased chances of cigarette smoking abstinence, while consistent non-daily vaping is associated with decreased chances of smoking abstinence.

Longer-term use of electronic cigarettes when provided as a stop smoking aid: Systematic review with meta-analyses

Moderate certainty evidence supports use of nicotine electronic cigarettes to quit smoking combustible cigarettes. However, there is less certainty regarding how long people continue to use e-cigarettes after smoking cessation attempts. We set out to synthesise data on the proportion of people still using e-cigarettes or other study products at 6 months or longer in studies of e-cigarettes for smoking cessation. We updated Cochrane searches (November 2021). For the first time, we meta-analysed prevalence of continued e-cigarette use among individuals allocated to e-cigarette conditions, and among those individuals who had successfully quit smoking. We updated meta-analyses comparing proportions continuing product use among individuals allocated to use nicotine e-cigarettes and other treatments. We included 19 studies (n = 7787). The pooled prevalence of continued e-cigarette use at 6 months or longer was 54% (95% CI: 46% to 61%, I2 86%, N = 1482) in participants assigned to e-cigarette conditions. Of participants who had quit combustible cigarettes overall 70% were still using e-cigarettes at six months or longer (95% CI: 53% to 82%, I2 73%, N = 215). Heterogeneity in direction of effect precluded meta-analysis comparing long-term use of nicotine e-cigarettes with NRT. More people were using nicotine e-cigarettes at longest follow-up compared to non-nicotine e-cigarettes, but CIs included no difference (risk ratio 1.15, 95% CI: 0.94 to 1.41, n = 601). The levels of continued e-cigarette use observed may reflect the success of e-cigarettes as a quitting tool. Further research is needed to establish drivers of variation in and implications of continued use of e-cigarettes.

Electronic cigarettes for smoking cessation

BACKGROUND

Electronic cigarettes (ECs) are handheld electronic vaping devices which produce an aerosol by heating an e-liquid. Some people who smoke use ECs to stop or reduce smoking, although some organizations, advocacy groups and policymakers have discouraged this, citing lack of evidence of efficacy and safety. People who smoke, healthcare providers and regulators want to know if ECs can help people quit smoking, and if they are safe to use for this purpose. This is a review update conducted as part of a living systematic review.

OBJECTIVES

To examine the effectiveness, tolerability, and safety of using electronic cigarettes (ECs) to help people who smoke tobacco achieve long-term smoking abstinence.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 July 2022, and reference-checked and contacted study authors.  SELECTION CRITERIA: We included randomized controlled trials (RCTs) and randomized cross-over trials, in which people who smoke were randomized to an EC or control condition. We also included uncontrolled intervention studies in which all participants received an EC intervention. Studies had to report abstinence from cigarettes at six months or longer or data on safety markers at one week or longer, or both.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods for screening and data extraction. Our primary outcome measures were abstinence from smoking after at least six months follow-up, adverse events (AEs), and serious adverse events (SAEs). Secondary outcomes included the proportion of people still using study product (EC or pharmacotherapy) at six or more months after randomization or starting EC use, changes in carbon monoxide (CO), blood pressure (BP), heart rate, arterial oxygen saturation, lung function, and levels of carcinogens or toxicants, or both. We used a fixed-effect Mantel-Haenszel model to calculate risk ratios (RRs) with a 95% confidence interval (CI) for dichotomous outcomes. For continuous outcomes, we calculated mean differences. Where appropriate, we pooled data in meta-analyses.

MAIN RESULTS

We included 78 completed studies, representing 22,052 participants, of which 40 were RCTs. Seventeen of the 78 included studies were new to this review update. Of the included studies, we rated ten (all but one contributing to our main comparisons) at low risk of bias overall, 50 at high risk overall (including all non-randomized studies), and the remainder at unclear risk. There was high certainty that quit rates were higher in people randomized to nicotine EC than in those randomized to nicotine replacement therapy (NRT) (RR 1.63, 95% CI 1.30 to 2.04; I2 = 10%; 6 studies, 2378 participants). In absolute terms, this might translate to an additional four quitters per 100 (95% CI 2 to 6). There was moderate-certainty evidence (limited by imprecision) that the rate of occurrence of AEs was similar between groups (RR 1.02, 95% CI 0.88 to 1.19; I2 = 0%; 4 studies, 1702 participants). SAEs were rare, but there was insufficient evidence to determine whether rates differed between groups due to very serious imprecision (RR 1.12, 95% CI 0.82 to 1.52; I2 = 34%; 5 studies, 2411 participants). There was moderate-certainty evidence, limited by imprecision, that quit rates were higher in people randomized to nicotine EC than to non-nicotine EC (RR 1.94, 95% CI 1.21 to 3.13; I2 = 0%; 5 studies, 1447 participants). In absolute terms, this might lead to an additional seven quitters per 100 (95% CI 2 to 16). There was moderate-certainty evidence of no difference in the rate of AEs between these groups (RR 1.01, 95% CI 0.91 to 1.11; I2 = 0%; 5 studies, 1840 participants). There was insufficient evidence to determine whether rates of SAEs differed between groups, due to very serious imprecision (RR 1.00, 95% CI 0.56 to 1.79; I2 = 0%; 8 studies, 1272 participants). Compared to behavioural support only/no support, quit rates were higher for participants randomized to nicotine EC (RR 2.66, 95% CI 1.52 to 4.65; I2 = 0%; 7 studies, 3126 participants). In absolute terms, this represents an additional two quitters per 100 (95% CI 1 to 3). However, this finding was of very low certainty, due to issues with imprecision and risk of bias. There was some evidence that (non-serious) AEs were more common in people randomized to nicotine EC (RR 1.22, 95% CI 1.12 to 1.32; I2 = 41%, low certainty; 4 studies, 765 participants) and, again, insufficient evidence to determine whether rates of SAEs differed between groups (RR 1.03, 95% CI 0.54 to 1.97; I2 = 38%; 9 studies, 1993 participants).  Data from non-randomized studies were consistent with RCT data. The most commonly reported AEs were throat/mouth irritation, headache, cough, and nausea, which tended to dissipate with continued EC use. Very few studies reported data on other outcomes or comparisons, hence evidence for these is limited, with CIs often encompassing clinically significant harm and benefit.

AUTHORS' CONCLUSIONS

There is high-certainty evidence that ECs with nicotine increase quit rates compared to NRT and moderate-certainty evidence that they increase quit rates compared to ECs without nicotine. Evidence comparing nicotine EC with usual care/no treatment also suggests benefit, but is less certain. More studies are needed to confirm the effect size. Confidence intervals were for the most part wide for data on AEs, SAEs and other safety markers, with no difference in AEs between nicotine and non-nicotine ECs nor between nicotine ECs and NRT. Overall incidence of SAEs was low across all study arms. We did not detect evidence of serious harm from nicotine EC, but longest follow-up was two years and the number of studies was small. The main limitation of the evidence base remains imprecision due to the small number of RCTs, often with low event rates, but further RCTs are underway. To ensure the review continues to provide up-to-date information to decision-makers, this review is a living systematic review. We run searches monthly, with the review updated when relevant new evidence becomes available. Please refer to the Cochrane Database of Systematic Reviews for the review's current status.

The point on the electronic cigarette more than 10 years after its introduction

Electronic cigarettes (e-cigarettes) are battery-powered devices containing a liquid based on propylene glycol or vegetable glycerin, compounds which, when vaporized, act as a vehicle for nicotine, flavours, and other chemical components. These devices have been marketed without clear evidence of risks, long-term safety, and efficacy as a means of traditional smoking cessation. Recent clinical studies have shown how the use of the e-cigarette, combined with adequate psychological support, can be effective in reducing traditional smoking but not nicotine addiction. However, meta-analyses of observational studies have not confirmed this efficacy. Several studies have also highlighted an increase in sympathetic tone, vascular stiffness, and endothelial dysfunction, all factors associated with an increased cardiovascular risk. Clinicians, therefore, should carefully monitor the possible risks to public health deriving from the use of e-cigarettes and should discourage non-smokers and adolescents from using such devices. Finally, particular attention should be paid to smokers so that the combined use of electronic and traditional cigarettes can be limited as much as possible.

Nicotine-Free E-Cigarettes Might Promote Tobacco Smoking Reduction Better Than Nicotine Delivery Devices: Results of a Double-Blind Randomized Controlled Trial at 1 Year

The purpose of the present study was to determine whether the use of e-cigarettes to aid in quitting contributed to the increase in the pulmonary health of chronic smokers. The efficacy of e-cigarettes to support a successful smoking cessation attempt was also investigated. A total of 210 smokers (78 women) were enrolled in a screening program for the early detection of lung cancer and distributed in three arms: nicotine e-cigarette plus support, nicotine-free e-cigarette plus support, and support. Results showed that participants in the nicotine e-cigarette arm had a significant and fast decrease in daily cigarettes, but that later they resume smoking more than the other two groups. Conversely, participants in the other two arms showed similar daily consumption at the two evaluation points. Among abstinent participants, only 12.5% reported cough, while 48% of current smokers had pulmonary symptoms. Our study suggests that, in the long run, the use of a nicotine-free liquid may favor reducing smoking and could be considered a good option in a clinical setting.

Modeling the longitudinal transitions of electronic cigarettes and conventional cigarettes with time-dependent covariates among adolescents

E-cigarettes may help combustible cigarette smokers switch to a less harmful alternative, or may increase the risk of subsequent initiation of cigarettes among non-smokers. Among youth, it is not clear whether both pathways occur equally, or whether one direction is more likely than the other. We used data from a prospective cohort study of youth in Southern California followed twice annually from Fall 2013 (9th grade) to Fall 2015 (11th grade) (N = 1977). A polytomous logistic regression model was used to simultaneously estimate transition rates for initiation of and abstention from e-cigarettes and cigarettes. Use of e-cigarettes was positively associated with initiation of cigarettes (OR = 7.57; 95%CI:[5.32, 10.8]) and negatively associated with cigarette abstention (OR = 0.58; 95%CI:[0.33, 0.99]) in adjusted models; cigarette use was positively associated with e-cigarette initiation (OR = 2.54; 95%CI:[1.45, 4.47]) and negatively associated with e-cigarette abstention (OR = 0.31; 95%CI:[0.17,0.57]). Uni-directional transition from e-cigarettes only to cigarettes only occurred less frequently than expected under independence (OR = 0.33; 95% CI [0.20, 0.55]), whereas simultaneously initiating both products (OR = 9.79; 95%CI:[7.22, 13.3]) and simultaneously abstaining (OR = 2.84; 95%CI:[1.50, 5.37]) were more frequent than expected. E-cigarettes were more strongly associated with subsequent cigarette initiation than the reverse, though both models indicated that use of either product seems to encourage use of the other. Models also indicated that use of either e-cigarettes or cigarettes resulted in reduced abstention of the other product. Findings suggest that prevention efforts for that continue to focus on both e-cigarettes and cigarettes are needed.

E-Cigarettes Reexamined: Product Toxicity

The introduction of e-cigarettes, or electronic nicotine delivery systems (ENDS), has been accompanied by controversy regarding their safety and effectiveness as a cessation aid and by an explosion in their use by youth. Their use does not involve the combustion of tobacco and the creation of harmful combustion products; they have been seen as a "harm reduction" tool that may be of assistance in promoting smoking cessation. Recognition that ENDS can deliver an array of chemicals and materials with known adverse consequences has spurred more careful examination of these products. Nicotine, nitrosamines, carbonyl compounds, heavy metals, free radicals, reactive oxygen species, particulate matter, and "emerging chemicals of concern" are among the constituents of the heated chemical aerosol that is inhaled when ENDS are used. They raise concerns for cardiovascular and respiratory health that merit the attention of clinicians and regulatory agencies. Frequently cited concerns include evidence of disordered respiratory function, altered hemodynamics, endothelial dysfunction, vascular reactivity, and enhanced thrombogenesis. The absence of evidence of the consequences of their long-term use is of additional concern. Their effectiveness as cessation aids and beneficial impact on health outcomes continue to be examined. It is important to ensure that their production and availability are thoughtfully regulated to optimise their safety and permit their use as harm reduction devices and potentially as smoking-cessation aids. It is equally vital to effectively prevent them from becoming ubiquitous consumer products with the potential to rapidly induce nicotine addiction among large numbers of youth. Clinicians should understand the nature of these products and the implications of their use.

Duration of the effectiveness of nicotine electronic cigarettes on smoking cessation and reduction: Systematic review and meta-analysis

Background

The success of pharmacotherapies for smoking cessation in real-life remains limited, with a significant number of long-term relapses. Despite first promising results, the duration of the effectiveness of electronic cigarettes is still unknown. Our objective was to assess the duration of the effectiveness of electronic cigarettes on smoking cessation and reduction in daily smokers.

Methods

The databases EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov and PUBMED were consulted until March 23, 2022. We selected only randomized controlled trials with daily adult smokers. The intervention was the nicotinic electronic cigarette vs. non-nicotine electronic cigarette or other validated pharmacotherapies (varenicline, bupropion and nicotine replacement therapy). The minimum duration of the intervention was 3 months, with a follow-up of at least 6 months. Two independent reviewers used the PRISMA guidelines. The primary endpoint was smoking cessation at the end of the intervention and follow-up periods confirmed by a reduction in expired CO < 10 ppm. The reduction was defined as at least 50% of the initial consumption or by a decrease of daily mean cigarette consumption at the end of the intervention and follow-up periods.

Results

Abstinence at the end of the intervention and follow-up periods was significantly higher in the nicotine electronic cigarette group, compared to nicotine replacement therapy (NRT) [respectively: RR: 1.37 (CI 95%: 1.32-2.93) and RR: 1.49 (CI 95%: 1.14-1.95)] and to the non-nicotine electronic cigarette condition [respectively: RR: 1.97 (CI 95%: 1.18-2.68) and RR: 1.66 (CI 95%: 1.01-2.73)]. With regard to smoking reduction, the electronic cigarette with nicotine is significantly more effective than NRT at the end of the intervention and follow-up periods [respectively RR: 1.48 (CI 95%: 1.04-2.10) and RR: 1.47 (CI 95%: 1.18-1.82)] and non-nicotine electronic cigarette in the long term [RR: 1.31 (CI 95%: 1.02-1.68)].

Conclusions

This meta-analysis shows the duration of the effectiveness of the nicotine electronic cigarette vs. non-nicotine electronic cigarette and NRT on smoking cessation and reduction. There are still uncertainties about the risks of its long-term use and its potential role as a gateway into smoking, particularly among young people.

Assessment of formal tobacco treatment and smoking cessation in dual users of cigarettes and e-cigarettes

BACKGROUND

The utility of electronic cigarettes ('e-cigarettes') as a smoking cessation adjunct remains unclear. Similarly, it is unclear if formal tobacco treatment (pharmacotherapy and/or behavioural support) augments smoking cessation in individuals who use both cigarettes and e-cigarettes.

METHODS

We performed a longitudinal cohort study of adult outpatients evaluated in our tertiary care medical centre (6/2018-6/2020). E-cigarette use, smoking status and formal tobacco treatment (deterrent pharmacotherapy and/or behavioural support) were assessed in 6-month blocks (eg, cohort 1 (C1)=6/2018-12/2018, C2=1/2019-6/2019 and so on) using our electronic health record. We assessed the relationship between e-cigarette use (either with or without formal tobacco treatment) and point prevalence of smoking cessation at 6 and 12 months.

RESULTS

111 823 unique patients were included in the study. The prevalence of dual use of cigarettes and e-cigarettes increased significantly over the study period (C1=0.8%; C2=1.1%; C3=1.8%; C4=2.3%; p<0.001). The prevalence of smoking cessation at 12 months was higher among e-cigarette users (20.8%) compared with non-users (16.8%) (risk difference, 4.0% (95% CI 2.5% to 5.5%); adjusted relative risk (aRR) 1.354, 95% CI 1.252 to 1.464, p<0.0001). Further, among dual users of cigarettes and e-cigarettes, the prevalence of smoking cessation at 12 months was higher among individuals who received tobacco treatment (29.1%) compared with individuals who did not receive tobacco treatment (19.6%) (risk difference, 9.5% (95% CI, 4.6% to 14.4%); aRR 1.238, 95% CI 1.071 to 1.432, p=0.004).

INTERPRETATION

These results suggest that dual users of cigarettes and e-cigarettes benefit from formal tobacco treatment. Clinicians should consider offering formal tobacco treatment to such patients, though future trials are needed.

Multiple Tobacco Product Use Conceptual Framework: A 2021 Update on Evidence

INTRODUCTION

One-third of adults in the United States who use tobacco regularly use two or more types of tobacco products. As the use of e-cigarettes and other noncombusted tobacco products increases-making multiple tobacco product (MTP) use increasingly common-it is essential to evaluate the complex factors that affect product use.

AIMS AND METHODS

In this update to our 2019 conceptual framework, we review and evaluate recent literature and expand the model to include ways in which MTP use may be affected by market factors such as the introduction of new products and socioenvironmental factors like marketing and advertising.

RESULTS AND CONCLUSIONS

MTP use patterns are complex, dynamic, and multiply determined by factors at the level of individuals, products, situations or contexts, and marketplace. Substitution, or using one product with the intent of decreasing use of another, and complementarity, or using multiple products for different reasons or purposes, explain patterns in MTP use. Moreover, substitution and complementarity may inform our understanding of how market changes targeted at one product, for instance, new product standards, bans, product pricing, and taxation, affect consumption of other tobacco products. New data from natural experiments and novel laboratory-based techniques add additional data and expand the framework.

IMPLICATIONS

A substantial proportion of people who use tobacco use more than one product. This review synthesizes and evaluates recent evidence on the diverse factors that affect MTP use in addition to expanding our framework. Our review is accompanied by suggested research questions that can guide future study.

Investigating the effect of e-cigarette use on quitting smoking in adults aged 25 years or more using the PATH study

Background: The evidence on harms and benefits of e-cigarettes partly concerns whether their use encourages smokers to quit.  We addressed this using data from the nationally representative PATH study, with detailed accounting for potential confounding variables.

Methods: We considered adults aged 25+.  Our original analyses, reported in version 1 of this paper, used data for Waves 1 to 3, separate analyses considering Waves 1 to 2, 2 to 3 and 1 to 3.  These related baseline ever e-cigarette use (or e-product use at Wave 2) to quitting at follow-up, adjusting for confounders derived from 55 candidates.  Sensitivity analyses omitted ever other product users, linked quitting to current e-cigarette use, and used values of some predictors modified using follow-up data.  Additional analyses used data for Waves 1 to 4, separately considering sustained, delayed and temporary quitting during Waves 1 to 3, 2 to 4 and 1 to 4.  Sensitivity analyses considered 30-day quitting, restricted attention to smokers attempting to quit, and considered ever smokeless tobacco or snus use.

Results: In the original analyses, unadjusted odds ratios (ORs) of quitting smoking for ever e-cigarette use were 1.29 (95% CI 1.01-1.66), 1.52 (1.26-1.83) and 1.47 (1.19-1.82) for the Wave 1 to 2, 2 to 3, and 1 to 3 analyses.  These reduced after adjustment, to 1.23 (0.94-1.61), 1.51 (1.24-1.85) and 1.39 (1.11-1.74).  Quitting rates remained elevated in users in all sensitivity analyses.  The additional analyses found associations of e-cigarette use with sustained, delayed and temporary quitting, associations little affected by considering 30-day quitting, and only slightly reduced restricting attention to quit attempters.  Ever use of smokeless tobacco or snus also predicted increased quitting.  

Conclusions: As does most evidence from clinical trials, other analyses of PATH, and other epidemiological studies, our results suggest using e-cigarettes helps adult smokers to quit.

Patterns and associations of smoking and electronic cigarette use among survivors of tobacco related and non-tobacco related cancers: A nationally representative cross-sectional analysis

BACKGROUND

Tobacco-use among cancer survivors leads to preventable morbidity, mortality, and increased healthcare costs. We sought to explore the prevalence of smoking and e-cigarette use among survivors of tobacco and non-tobacco related cancers.

METHODS

A cross-sectional analysis was conducted using the 2015-2018 National Health Interview Survey. Our primary outcome was the prevalence of current cigarette smoking or e-cigarette use among adults with self-reported history of tobacco related or non-tobacco related cancer. Logistic regression analysis was to assess the association of reported cancer type with cigarette smoking or e-cigarette use. Secondary outcomes included yearly trends and dual use.

RESULTS

A total of 12,984 respondents reported a history of cancer, representing a weighted estimate of 5,060,059 individuals with a history of tobacco-related malignancy and 17,583,788 with a history of a tobacco and non-tobacco related cancer, respectively. Survivors of tobacco-related cancers had a significantly higher prevalence of current cigarette use (18.2 % vs 9.7 %, P < 0.0001), e-cigarette use (2.7 % vs 1.6 %, P < 0.0001) and similar rates of dual use. The prevalence of cigarette smoking among all survivors increased as time increased from the year of diagnosis up to 2 years post-diagnosis (P = 0.047). Odds of reporting current cigarette smoking use was higher for survivors of tobacco-related cancers, adjusted for sociodemographic factors (OR1.69, 95 % CI 1.44-1.99).

CONCLUSIONS

Survivors of tobacco-related cancers have a higher prevalence of current cigarette smoking and e-cigarette use compared to survivors of non-tobacco related cancers. There was a sequential increase in the prevalence of cigarette use during each subsequent year from the time of a new cancer diagnosis, underscoring the need for long term tobacco cessation support among newly diagnosed adults with cancer.

Understanding contexts of smoking and vaping among dual users: analysis of ecological momentary assessment data

AIMS

To understand dual users' cigarette and e-cigarette use patterns, including the contexts in which they vape versus smoke and to understand how environmental and internal contexts and smoking patterns differ between dual users and exclusive smokers.

DESIGN

Longitudinal observational trial.

SETTING

Research center in Wisconsin, USA.

PARTICIPANTS

Adult dual users (n = 162) and adults who exclusively smoked (n = 143), with no plans to quit smoking or vaping in the next 30 days.

MEASUREMENTS

Participants carried smartphones for 2 weeks at baseline to record each use event for the two products and report on the context of their product use. The percentage of mornings where participants vaped first versus smoked were used to compute e-cigarette dependence.

FINDINGS

Hierarchical linear regression models with random slopes and intercepts examined the within- and between-subject effects of context on the likelihood of vaping (versus smoking); significant fixed effects were tested for moderation by e-cigarette dependence. Dual users reported significantly more puffs/cigarette [mean = 13.1, standard deviation (SD) = 10.2] than puffs/vape event (mean = 11.7, SD = 11.5; P = 0.01). E-cigarette dependence moderated the influence of social cues (t-ratio = 2.4, P = 0.02) and smoking restrictions (t-ratio = 3.1, P = 0.003) on the likelihood of vaping versus smoking [odds ratio (OR) = 2.30, P = 0.02]. Context was more related to which product was used in those of low versus higher e-cigarette dependence. Reports of strong cravings to smoke and positive expectancies for cigarettes were associated with a reduced likelihood of vaping, whereas strong cravings to vape and positive vaping expectancies were related to increased likelihood of vaping.

CONCLUSIONS

Among dual users of cigarettes and e-cigarettes with no motivation to quit, vaping appears to be related to internal cues and more highly linked with social contexts and smoking restrictions (i.e. under stronger external stimulus control) among those with low to moderate e-cigarette dependence compared with high e-cigarette dependence. These findings illustrate the importance of contextual factors in tobacco product use among dual users with the influence of context being reduced at high levels of e-cigarette dependence.

E-Cigarettes and Cardiopulmonary Health: Review for Clinicians

Electronic cigarettes (e-cigarettes) are battery powered electronic nicotine delivery systems that use a propylene glycol/vegetable glycerin base to deliver vaporized nicotine and flavorings to the body. E-cigarettes became commercially available without evidence regarding their risks, long-term safety, or utility in smoking cessation. Recent clinical trials suggest that e-cigarette use with counseling may be effective in reducing cigarette use but not nicotine dependence. However, meta-analyses of observational studies demonstrate that e-cigarette use is not associated with smoking cessation. Cardiovascular studies reported sympathetic activation, vascular stiffening, and endothelial dysfunction, which are associated with adverse cardiovascular events. The majority of pulmonary clinical trials in e-cigarette users included standard spirometry as the primary outcome measure, reporting no change in lung function. However, studies reported increased biomarkers of pulmonary disease in e-cigarette users. These studies were conducted in adults, but >30% of high school-age adolescents reported e-cigarette use. The effects of e-cigarette use on cardiopulmonary endpoints in adolescents and young adults remain unstudied. Because of adverse clinical findings and associations between e-cigarette use and increased incidence of respiratory diseases in people who have never smoked, large longitudinal studies are needed to understand the risk profile of e-cigarettes. Consistent with the Centers for Disease Control and Prevention recommendations, clinicians should monitor the health risks of e-cigarette use, discourage nonsmokers and adolescents from using e-cigarettes, and discourage smokers from engaging in dual use without cigarette reduction or cessation.

Negative Affect and Cigarette Cessation in Dual Users of Cigarettes and Electronic Nicotine Delivery Systems

Objectives: Dual use of cigarettes and electronic nicotine delivery systems (ENDS) is increasingly common in adult smokers, who often report using ENDS to quit smoking. Elevated negative affect is an established predictor of increased difficulty quitting smoking combustible cigarettes but has not yet been examined in the context of cigarette cessation for dual users. Method: This study examined whether mood-related factors predict cigarette smoking cessation among dual users (N = 364) over 12-months. Self-reported cigarette smoking at 12 months, with abstinence defined as no smoking for the past 7 days, was the primary outcome variable. Logistic regression included baseline levels of depression symptoms (CES-D), anxiety symptoms (MASQ), and negative affect expectancies for smoking, with baseline nicotine dependence for cigarettes (NDSS), motivation to quit, age, race/ethnicity, rate of cigarette smoking at baseline, and ENDS usage at baseline and 12 months as covariates. Interactions between CES-D, MASQ, and negative affect expectancies were examined. We predicted that negative affect, especially for smokers who had high negative affect expectancies for smoking, would be negatively associated with quitting. Results: Contrary to expectations, negative affect constructs did not predict quitting. Baseline nicotine dependence for cigarettes, gender, and race/ethnicity significantly predicted the likelihood of cigarette cessation. Higher rates of ENDS use, higher motivation, and lower negative affect smoking expectancies were significantly correlated with quitting cigarettes. Conclusion: In this non-treatment seeking sample of dual users, negative affect did not predict cigarette cessation over and above nicotine dependence for cigarettes, gender, and race/ethnicity.

Varenicline for Gradual Versus Abrupt Smoking Cessation in Poorly Motivated Smokers With COPD: A Prematurely Terminated Randomized Controlled Trial

Background

Although smoking is the leading cause of chronic obstructive pulmonary disease (COPD), many patients with COPD smoke, highlighting the need for effective smoking cessation interventions in this population. This study examined the efficacy and safety of varenicline in increasing smoking cessation rates through "gradual" versus "abrupt" cessation in COPD patients with low motivation to quit smoking.

Methods

A randomized, open label, 30-week, controlled trial (ClinicalTrials.gov identifier: NCT02894957) was conducted between January 2019 and October 2020 at a center in Israel. Smokers with COPD, poorly motivated to quit, were randomized to 6 weeks of varenicline for smoking reduction and a target quit day (TQD) at the end of week 6 (gradual cessation group) or ad libitum smoking for 5 weeks, 1 week of varenicline, and a TQD at the end of week 6 (abrupt cessation group). After the pre-quit phase, both groups received 12-week regular varenicline treatment and 12-week follow-up. Primary outcome was biochemically-validated continuous abstinence for weeks 6-30. Secondary outcomes were: (1) biochemically-confirmed7-day point prevalence abstinence for weeks 4-30, (2) efficient smoking reduction (≥50% in number of cigarettes/day) in the pre-quit phase; and (3) number of cigarettes/day, motivation to quit, and changes in respiratory symptoms and spirometry from baseline through week 30.

Results

A drug recall issued by the study sponsor stopped the study after 70/242 (28.9%) patients had been enrolled. The gradual cessation group (n=29) had significantly higher continuous abstinence rates from TQD through week 30 versus the abrupt cessation group (n=41): 20.7% versus 4.9% (odds ratio [OR]=5.09; 95% confidence interval [CI] 0.89-29.17; p=0.048) and higher 7-day point prevalence abstinence levels at all time points but week 18 (p=0.027 at week 6, 0.056 at week 7, and 0.096 at week 9). Motivation to quit increased (p=0.002) and the number of cigarettes/day decreased (p=0.002) over time in both groups. Respiratory symptoms, but not spirometry, improved in both groups at week 30. Treatment was safe and well tolerated.

Conclusion

In poorly motivated smokers with COPD, using varenicline for a 6-week gradual smoking cessation before TQD, compared with abrupt cessation, significantly increased quit rates up to 6 months. Results were not affected by the smaller-than-expected sample size. Further studies are needed to confirm these data.

Efficacy and safety of electronic cigarettes as a smoking cessation intervention: A systematic review and network meta-analysis

INTRODUCTION

This systematic review of randomized controlled trials (RCTs) evaluated the efficacy and safety of electronic cigarettes (e-cigarettes, ENDS) in helping people who smoke to achieve abstinence compared with electronic non-nicotine delivery systems (ENNDS, no nicotine) or any smoking cessation comparator treatment or combination of treatments at 24–26 weeks and at 52 weeks.

METHODS

Systematic review techniques involved searches of three databases in February 2020 with update searches run on 14 May 2021, two-person independent screening, two-person independent assessment of bias, formal extraction of data with verification by a second person, a feasibility assessment to decide if meta-analysis was appropriate, and network meta-analysis (NMA) of data at 24–26 weeks. Data at 52 weeks were narratively summarized.

RESULTS

Ten RCTs met the inclusion criteria, eight for efficacy and ten for safety. Eight of the nine RCTs were assessed as at high risk of bias. The sample sizes of the RCTs were 30–2012. Using nicotine replacement therapy (NRT) as the reference treatment, the incidences of smoking cessation at 24–26 weeks were comparable between ENDS and NRT groups (RR=1.17; 95% CrI: 0.66–1.86). Three sensitivity analyses were carried out indicating the main findings for 24–26 weeks were robust to assumptions. The findings at 52 weeks were inconclusive.

CONCLUSIONS

This systematic review and NMA indicates that there is no clear evidence of a difference in effect between nicotine containing e-cigarettes and NRT on incidences of smoking cessation at 24–26 weeks, and substantial uncertainty remains.

How to manage cigarette smoking in kidney transplant candidates and recipients?

Tobacco smoking is a frequent problem affecting many kidney transplant (KT) candidates and recipients. The negative impact of active smoking on KT outcomes has been demonstrated. Consequently, most guidelines strongly recommend quitting smoking before considering kidney transplantation. However, nicotine addiction is a complex multifactorial disease and only 3-5% of the patients who try to quit by themselves achieve prolonged abstinence. Smoking cessation programmes (SCPs) have proven their efficacy in the general population to increase the rate of quitting and should therefore be proposed to all smoking KT candidates and recipients. Nevertheless, SCPs have not been evaluated in the KT field and not all KT centres have easy access to these programmes. In this work, we aim to review the current knowledge on the subject and provide an overview of the available interventions to help smoking patients quit. We detail non-pharmaceutical and pharmaceutical approaches and discuss their use in KT candidates and recipients.

[Diversification of smoking cessation programmes-the role of e-cigarettes]

The question of whether e‑cigarettes are a useful tool for smoking cessation is part of an ongoing and highly controversial scientific debate. In practice, however, the number of people trying to quit tobacco consumption by using these products is steadily increasing. This discussion article provides an outline of the current state of research on the issue of whether and to what extent e‑cigarettes can help people quit smoking.Of course, e‑cigarettes also have a certain potential for harm, especially if nicotine dependence is unnecessarily prolonged. Nevertheless, it can make an important contribution to harm reduction in nicotine consumption. Hence, the product should get treated as a serious alternative to nicotine replacement therapies (NRTs) in the scientific discussion. Like NRTs, e‑cigarettes offer a less harmful way of consuming nicotine that greatly reduces many of the health risks associated with tobacco consumption, such as the absorption of carcinogenic substances. Recent studies and reviews suggest that the product can be at least as effective as nicotine replacement therapies in helping people quit smoking. Individual studies even demonstrate the increased effectiveness of e‑cigarettes in supporting smoking cessation.Nevertheless, the review of the current literature shows that more high-quality research is needed to further understand the product and its properties. In terms of the harm reduction approach, however, it would already be more appropriate to also rely on e‑cigarettes instead of trying to force immediate and complete nicotine abstinence. After all, in the process of quitting smoking, the fastest possible cessation of the more unhealthy consumption of tobacco should be prioritized in order to immediately minimize unnecessary health risks.

Oral and periodontal implications of tobacco and nicotine products

Tobacco use contributes to more mortality and morbidity globally than any other behavioral risk factor. Adverse effects do not spare the oral cavity, with many oral diseases more common, and treatments less successful, in the tobacco-using patient. Many of the oral health effects of cigarette smoking are well established, but other forms of tobacco, including cigars and smokeless tobacco, merit dental professionals' attention. Recently, an expanding variety of new or emerging tobacco and/or nicotine products has been brought to market, most prominently electronic cigarettes, but also including heated tobacco and other noncombustible nicotine products. The use of cannabis (marijuana) is increasing and also has risks for oral health and dental treatment. For the practicing periodontist, and all dental professionals, providing sound patient recommendations requires knowledge of the general and oral health implications associated with this wide range of tobacco and nicotine products and cannabis. This review provides an overview of selected tobacco and nicotine products with an emphasis on their implications for periodontal disease risk and clinical management. Also presented are strategies for tobacco use counselling and cessation support that dental professionals can implement in practice.

Incidence of Cigarette Smoking Relapse Among Individuals Who Switched to e-Cigarettes or Other Tobacco Products

IMPORTANCE

Although e-cigarettes are not approved as a cessation device, many who smoke believe that e-cigarettes will help them quit cigarette smoking successfully.

OBJECTIVE

To assess whether people who recently quit smoking and who had switched to e-cigarettes or another tobacco product were less likely to relapse to cigarette smoking compared with those who remained tobacco free.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study analyzed a nationally representative sample of US households that participated in 4 waves of the Population Assessment of Tobacco and Health Study (conducted 2013 through 2017), combining 2 independent cohorts each with 3 annual surveys. Eligible participants were individuals who smoked at baseline, had recently quit at the first follow-up, and completed the second follow-up survey.

EXPOSURES

Use of e-cigarettes or alternate tobacco products at follow-up 1 after recently quitting smoking.

MAIN OUTCOMES AND MEASURES

Weighted percentage of participants with over 12 months abstinence by follow-up 2.

RESULTS

Of a total of 13 604 participants who smoked cigarettes at baseline, 9.4% (95% CI, 8.7%-10.0%) recently had quit smoking (mean age, 41.9; 95% CI, 39.7-46.6 years; 641 [43.2%] women) Of these, 22.8% (95% CI, 19.7%-26.0%) had switched to e-cigarettes, with 17.6% (95% CI, 14.8%-20.5%) using them daily. A total of 37.1% (95% CI, 33.7%-40.4%) used a noncigarette tobacco product and 62.9% (95% CI, 59.6%-66.3%) were tobacco free. Rates of switching to e-cigarettes were highest for those who were in the top tertile of tobacco dependence (31.3%; 95% CI, 25.0%-37.7%), were non-Hispanic White (26.4%; 95% CI, 22.3%-30.4%), and had higher incomes (annual income ≥$35 000, 27.5%; 95% CI, 22.5%-32.4% vs <$35 000, 19.3%; 95% CI, 16.3%-22.3%). At follow-up 2, unadjusted relapse rates were similar among those who switched to different tobacco products (for any tobacco product: successfully quit, 41.5%; 95% CI, 36.2%-46.9%; relapsed with significant requit, 17.0%; 95% CI, 12.4%-21.6%; currently smoking, 36.2%; 95% CI, 30.9%-41.4%). Controlled for potential confounders, switching to any tobacco product was associated with higher relapse rate than being tobacco free (adjusted risk difference, 8.5%; 95% CI, 0.3%-16.6%). Estimates for those who switched to e-cigarettes, whether daily or not, were not significant. While individuals who switched from cigarettes to e-cigarettes were more likely to relapse, they appeared more likely to requit and be abstinent for 3 months at follow-up 2 (17.0%; 95% CI, 12.4%-21.6% vs 10.4%; 95% CI, 8.0%-12.9%).

CONCLUSIONS AND RELEVANCE

This large US nationally representative study does not support the hypothesis that switching to e-cigarettes will prevent relapse to cigarette smoking.

Factors associated with past-year attempts to quit e-cigarettes among current users: Findings from the Population Assessment of Tobacco and Health Wave 4 (2017-2018)

Over 10 million adults report use of electronic nicotine delivery systems (ENDS), with approximately 3.6 million reporting daily use. Even as the popularity of ENDS has increased, both as an available nicotine delivery system and an alternative to combustible cigarette smoking, few studies to date have examined ENDS cessation interest and related behaviors among ENDS users. The current study aimed to describe past year attempts to quit ENDS among current users and to investigate ENDS use / user characteristics associated with unsuccessful attempts to quit in the past year among adult, current, established ENDS users using data from the Population Assessment of Tobacco and Health (PATH) Study Wave 4. Over 10 % of ENDS users reported an attempt to quit completely in the past year, and 60 % indicated future intention to quit completely. Higher nicotine dependence, lower-frequency ENDS use, and higher interest in quitting were associated with past year attempts to quit ENDS. The current study adds support to claims that many ENDS users plan to quit using ENDS someday and highlights the need for continued research on ENDS cessation.

Perceptions of e-cigarette harm among cancer survivors: Findings from a nationally representative survey

BACKGROUND

The growth in e-cigarette use may be driven by the perception that they are a safer, healthier alternative to conventional cigarettes. However, their long-term health implications are not well known and use is discouraged by most cancer societies. It is currently unclear how cancer survivors perceive the risks associated with e-cigarette and how this may influence use in this population.

METHODS

A cross-sectional analysis was conducted using the Health Information National Trends Survey (HINTS) (Years 2017-2019). Our primary study outcome was the perception of harm associated with e-cigarettes compared to traditional cigarettes among adults with and without a self-reported history of cancer. We used logistic regression analyses assessing the association of a cancer history with the perception that e-cigarettes are as much or more harmful than cigarettes.

RESULTS

A total of 11,846 respondents (weighted population estimate 243,728,483) were included. Of these, 26.6% reported a history of cancer. The proportion of cancer survivors who perceived e-cigarettes to be as much or more harmful than conventional cigarettes was similar to non-cancer respondents (70.6% vs 68.3%, P = 0.35). There was no difference in perception of harm among cancer and non-cancer respondents, adjusted for sociodemographic factors (OR 0.82, 95% CI 0.6-1.1). Past (OR 9.06, 95% Cl 5.06-16.20) and never e-cigarette use (OR 23.40, 95% Cl 13.56-40.38) as well as having a history of cardiopulmonary disease (OR 1.28, 95% Cl 1.05-1.56) was associated with higher odds of perceiving e-cigarettes to be as much or more harmful.

CONCLUSION

Cancer survivors commonly perceive e-cigarettes to be as much or more harmful than traditional cigarettes though these findings are similar to perceptions among adults without a history of cancer. There is a strong association with avoidance of e-cigarette products among those who perceive them to be harmful.

Electronic cigarettes for smoking cessation

BACKGROUND

Electronic cigarettes (ECs) are handheld electronic vaping devices which produce an aerosol formed by heating an e-liquid. Some people who smoke use ECs to stop or reduce smoking, but some organizations, advocacy groups and policymakers have discouraged this, citing lack of evidence of efficacy and safety. People who smoke, healthcare providers and regulators want to know if ECs can help people quit and if they are safe to use for this purpose. This is an update conducted as part of a living systematic review.

OBJECTIVES

To examine the effectiveness, tolerability, and safety of using electronic cigarettes (ECs) to help people who smoke tobacco achieve long-term smoking abstinence.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 May 2021, and reference-checked and contacted study authors. We screened abstracts from the Society for Research on Nicotine and Tobacco (SRNT) 2021 Annual Meeting.   SELECTION CRITERIA: We included randomized controlled trials (RCTs) and randomized cross-over trials, in which people who smoke were randomized to an EC or control condition. We also included uncontrolled intervention studies in which all participants received an EC intervention. Studies had to report abstinence from cigarettes at six months or longer or data on safety markers at one week or longer, or both.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods for screening and data extraction. Our primary outcome measures were abstinence from smoking after at least six months follow-up, adverse events (AEs), and serious adverse events (SAEs). Secondary outcomes included the proportion of people still using study product (EC or pharmacotherapy) at six or more months after randomization or starting EC use, changes in carbon monoxide (CO), blood pressure (BP), heart rate, arterial oxygen saturation, lung function, and levels of carcinogens or toxicants or both. We used a fixed-effect Mantel-Haenszel model to calculate risk ratios (RRs) with a 95% confidence interval (CI) for dichotomous outcomes. For continuous outcomes, we calculated mean differences. Where appropriate, we pooled data in meta-analyses.

MAIN RESULTS

We included 61 completed studies, representing 16,759 participants, of which 34 were RCTs. Five of the 61 included studies were new to this review update. Of the included studies, we rated seven (all contributing to our main comparisons) at low risk of bias overall, 42 at high risk overall (including all non-randomized studies), and the remainder at unclear risk. There was moderate-certainty evidence, limited by imprecision, that quit rates were higher in people randomized to nicotine EC than in those randomized to nicotine replacement therapy (NRT) (risk ratio (RR) 1.53, 95% confidence interval (CI) 1.21 to 1.93; I2 = 0%; 4 studies, 1924 participants). In absolute terms, this might translate to an additional three quitters per 100 (95% CI 1 to 6). There was low-certainty evidence (limited by very serious imprecision) that the rate of occurrence of AEs was similar (RR 0.98, 95% CI 0.80 to 1.19; I2 = 0%; 2 studies, 485 participants). SAEs were rare, but there was insufficient evidence to determine whether rates differed between groups due to very serious imprecision (RR 1.30, 95% CI 0.89 to 1.90: I2 = 0; 4 studies, 1424 participants). There was moderate-certainty evidence, again limited by imprecision, that quit rates were higher in people randomized to nicotine EC than to non-nicotine EC (RR 1.94, 95% CI 1.21 to 3.13; I2 = 0%; 5 studies, 1447 participants). In absolute terms, this might lead to an additional seven quitters per 100 (95% CI 2 to 16). There was moderate-certainty evidence of no difference in the rate of AEs between these groups (RR 1.01, 95% CI 0.91 to 1.11; I2 = 0%; 3 studies, 601 participants). There was insufficient evidence to determine whether rates of SAEs differed between groups, due to very serious imprecision (RR 1.06, 95% CI 0.47 to 2.38; I2 = 0; 5 studies, 792 participants). Compared to behavioural support only/no support, quit rates were higher for participants randomized to nicotine EC (RR 2.61, 95% CI 1.44 to 4.74; I2 = 0%; 6 studies, 2886 participants). In absolute terms this represents an additional six quitters per 100 (95% CI 2 to 15). However, this finding was of very low certainty, due to issues with imprecision and risk of bias. There was some evidence that non-serious AEs were more common in people randomized to nicotine EC (RR 1.22, 95% CI 1.12 to 1.32; I2 = 41%, low certainty; 4 studies, 765 participants), and again, insufficient evidence to determine whether rates of SAEs differed between groups (RR 1.51, 95% CI 0.70 to 3.24; I2 = 0%; 7 studies, 1303 participants).  Data from non-randomized studies were consistent with RCT data. The most commonly reported AEs were throat/mouth irritation, headache, cough, and nausea, which tended to dissipate with continued use. Very few studies reported data on other outcomes or comparisons, hence evidence for these is limited, with CIs often encompassing clinically significant harm and benefit.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that ECs with nicotine increase quit rates compared to NRT and compared to ECs without nicotine. Evidence comparing nicotine EC with usual care/no treatment also suggests benefit, but is less certain. More studies are needed to confirm the effect size. Confidence intervals were for the most part wide for data on AEs, SAEs and other safety markers, with no difference in AEs between nicotine and non-nicotine ECs. Overall incidence of SAEs was low across all study arms. We did not detect  evidence of harm from nicotine EC, but longest follow-up was two years and the  number of studies was small. The main limitation of the evidence base remains imprecision due to the small number of RCTs, often with low event rates, but further RCTs are underway. To ensure the review continues to provide up-to-date information to decision-makers, this review is now a living systematic review. We run searches monthly, with the review updated when relevant new evidence becomes available. Please refer to the Cochrane Database of Systematic Reviews for the review's current status.

Electronic Nicotine Delivery Systems (ENDS) Use and Pregnancy I: ENDS Use Behavior During Pregnancy

PURPOSE OF REVIEW

This review examines Electronic Nicotine Delivery Systems (ENDS) use behavior during pregnancy, including the prevalence of and transitions in use during pregnancy.

RECENT FINDINGS

Twenty-two papers addressed the prevalence of and/or transitions in ENDS use during pregnancy. Findings show a complex landscape of ENDS use. A minority (0.4%-7.0%) of pregnant persons use ENDS; most commonly this occurs in the form of dual use (ENDS and combustible cigarettes (CC); 75%). Many pregnant persons report using ENDS because they perceive them to be a lower-risk alternative and/or potential cessation aide for CC smoking. However, while a subset of those who use ENDS do quit all tobacco product use during pregnancy, only a small proportion switch from exclusive CC smoking to exclusive ENDS use.

SUMMARY

ENDS are a somewhat new addition to the tobacco product landscape. The perception of ENDS as a lower-risk alternative may contribute to ENDS use in pregnancy. There is insufficient evidence to support the notion that ENDS facilities the cessation of tobacco product use during pregnancy.

Clinical Pharmacology of Electronic Nicotine Delivery Systems (ENDS): Implications for Benefits and Risks in the Promotion of the Combusted Tobacco Endgame

Electronic nicotine delivery systems (ENDS) such as e-cigarettes and heated tobacco products are novel battery-operated devices that deliver nicotine without combustion of tobacco. Because cigarette smoking is sustained by nicotine addiction and the toxic combustion products are mainly responsible for the harmful effects of smoking, ENDS could be used to promote smoking cessation while exposing users to lower levels of toxicants compared with conventional cigarettes. The currently available evidence from clinical and observational studies indicates a potential role of e-cigarettes as smoking cessation aids, although many continue to use e-cigarettes long after quitting smoking. Nicotine and toxicant delivery vary considerably by device and depend on the characteristics of the e-liquid formulation. Because smokers tend to titrate their nicotine intake to maintain their desired pharmacologic effects, device and liquid characteristics need to be considered when using ENDS as an aid to quit smoking. Factors potentially limiting their use are the currently still unknown long-term safety of these products and concerns regarding widespread use among youth. Implications of clinical pharmacology data on ENDS for the cigarette endgame and regulation by the U.S. Food and Drug administration are discussed.

Guidelines for Reporting Trial Protocols and Completed Trials Modified Due to the COVID-19 Pandemic and Other Extenuating Circumstances: The CONSERVE 2021 Statement

IMPORTANCE

Extenuating circumstances can trigger unplanned changes to randomized trials and introduce methodological, ethical, feasibility, and analytical challenges that can potentially compromise the validity of findings. Numerous randomized trials have required changes in response to the COVID-19 pandemic, but guidance for reporting such modifications is incomplete.

OBJECTIVE

As a joint extension for the CONSORT and SPIRIT reporting guidelines, CONSERVE (CONSORT and SPIRIT Extension for RCTs Revised in Extenuating Circumstances) aims to improve reporting of trial protocols and completed trials that undergo important modifications in response to extenuating circumstances.

EVIDENCE

A panel of 37 international trial investigators, patient representatives, methodologists and statisticians, ethicists, funders, regulators, and journal editors convened to develop the guideline. The panel developed CONSERVE following an accelerated, iterative process between June 2020 and February 2021 involving (1) a rapid literature review of multiple databases (OVID Medline, OVID EMBASE, and EBSCO CINAHL) and gray literature sources from 2003 to March 2021; (2) consensus-based panelist meetings using a modified Delphi process and surveys; and (3) a global survey of trial stakeholders.

FINDINGS

The rapid review yielded 41 673 citations, of which 38 titles were relevant, including emerging guidance from regulatory and funding agencies for managing the effects of the COVID-19 pandemic on trials. However, no generalizable guidance for all circumstances in which trials and trial protocols might face unanticipated modifications were identified. The CONSERVE panel used these findings to develop a consensus reporting guidelines following 4 rounds of meetings and surveys. Responses were received from 198 professionals from 34 countries, of whom 90% (n = 178) indicated that they understood the concept definitions and 85.4% (n = 169) indicated that they understood and could use the implementation tool. Feedback from survey respondents was used to finalize the guideline and confirm that the guideline's core concepts were applicable and had utility for the trial community. CONSERVE incorporates an implementation tool and checklists tailored to trial reports and trial protocols for which extenuating circumstances have resulted in important modifications to the intended study procedures. The checklists include 4 sections capturing extenuating circumstances, important modifications, responsible parties, and interim data analyses.

CONCLUSIONS AND RELEVANCE

CONSERVE offers an extension to CONSORT and SPIRIT that could improve the transparency, quality, and completeness of reporting important modifications to trials in extenuating circumstances such as COVID-19.

Effectiveness of Non-Nicotinic E-Cigarettes to Reduce Cue- and Abstinence-Induced Cigarette Craving in Non-Treatment Seeking Daily Dependent Smokers

RATIONALE

Electronic cigarettes (e-cigarettes) are potential tools for smoking cessation because they deliver nicotine and simulate smoking behaviors. The contribution of sensorimotor versus pharmacological substitution is unknown.

OBJECTIVES

To evaluate whether non-nicotinic e-cigarettes, used alone or with nicotine lozenges, can attenuate cigarette craving following visual cue presentation or acute (3 h post ad-lib use) abstinence in dependent daily smokers.

METHODS

Following overnight (12 hours) abstinence, 41 daily smokers were exposed to 4 experimental conditions on separate days: (i) tobacco cigarettes (CIG); (ii) non-nicotinic e-cigarettes with placebo lozenges (EPL); (iii) non-nicotinic e-cigarettes with 4 mg nicotine lozenge (ENL); and (iv) 4 mg nicotine lozenge (NL). Cigarette craving was assessed following presentation of neutral and smoking cues at various time points using the Brief Questionnaire of Smoking Urges (QSU-B) and visual analog scales (VAS).

RESULTS

All experimental conditions significantly reduced participants' baseline overnight abstinence cigarette craving. ENLs and NLs attenuated smoking-cue-induced cravings to a greater extent than CIGs, where cravings were significantly higher with CIGs compared to ENLs [mean difference (MD) ± standard error (SE) in QSU-B = 3.2 ± 0.84, P = 0.002; VAS = 12.7 ± 2.7, P < 0.0005] and NLs [MD ± SE in QSU-B = 2.7 ± 0.92, P = 0.031; VAS = 8.1 ± 2.3, P = 0.005]. Craving responses to cues after 3 h were higher after smoking CIGs compared to ENLs [MD ± SE in QSU-B = 3.9 ± 1.4, P = 0.047; VAS = 14.1 ± 3.6, P = 0.002] and NLs [MD ± SE in QSU-B = 3.2 ± 1.1, P = 0.046; VAS = 9.7 ± 3.1, P = 0.017].

CONCLUSIONS

Behavioral simulation of smoking with or without nicotine reduces nicotine craving. Compared to cigarettes, ENL with NL or NL alone attenuates cigarette craving over time. Future clinical trials should evaluate the combination of ENL and NL as a method for smoking reduction or cessation.

TRIAL REGISTRATION

NCT02108626.

Alternative tobacco products use and its impact on urologic health - will the lesser evil still be evil? A commentary and review of literature

INTRODUCTION

Alternative tobacco products, including electronic cigarettes (e-cigarettes) and non-combustible tobacco products or heat-not-burn (HNB) products, are substitutes to conventional combustible cigarettes with the potential to impact urologic health, similar to traditional smoking. Most urologists, however, have limited knowledge of these products and are unfamiliar with their potential health implications. We conducted a review to assess the impact of e-cigarettes and HNB products on urologic health.

MATERIAL AND METHODS

A bibliographic search covering the period up to April, 2021 was conducted using MEDLINE®/PubMed® and Google Scholar. Articles were reviewed and categorized based on the potential impact on erectile dysfunction, semen quality, lower urinary tract symptoms, genitourinary malignancies, and smoking cessation. Data were extracted, analyzed and summarized.

RESULTS

Mature data on the long-term impact of e-cigarette and HNB product use on urologic health are lacking. E-cigarette and HNB vapors appear to contain decreased concentrations of chemicals responsible for erectile dysfunction compared to tobacco smoke but may play a role through endothelial damage. Use of e-cigarettes is associated with lower sperm counts. No definitive data has shown a link between e-cigarette or HNB product use and lower urinary tract symptoms. Multiple carcinogens including those specifically linked to bladder cancer have been identified in the urine of e-cigarette and HNB product users. Limited data suggest e-cigarettes may aid in smoking cessation.

CONCLUSIONS

Urologists may benefit from understanding the urologic health concerns surrounding e-cigarettes and HNB product use and patients may benefit from being properly educated.