Electronic cigarette use in young people in Great Britain 2013–2014

Exposure to E-Cigarette Advertising and Its Association With E-Cigarette Use Among Youth and Adolescents in Two Largest Cities in Vietnam 2020

BACKGROUND

E-cigarette products have become more popular due to the marketing campaigns on various sources but caused adverse health impacts to users, especially adolescents and youths. This paper aims to describe the situation of exposure to e-cigarette advertisements of youth and adolescents living in two cities of Hanoi and Ho Chi Minh in 2020 and identify the associated factors of e-cigarette marketing with e-cigarettes use in these groups.

METHODOLOGY

This was a cross-sectional study. The study participants were 1211 youth and adolescents aged 15-24 living in Hanoi and Ho Chi Minh City during the time of data collection (from January 2020 to September 2020). Two primary outcome variables included the ever e-cigarettes use and the intention to use e-cigarettes. Multivariate logistic regression models were used to assess the association between the outcome variables and e-cigarette marketing exposure.

RESULTS

The proportion of participants who ever use e-cigarettes was 7.4% and a proportion of 4.8% have intention to use e-cigarettes. The most popular source of exposure to e-cigarettes advertisements was social network (Facebook, Twitter, Instagram, Youtube, etc.) and this source had positive association with the odds of e-cigarette smoking among youth and adolescents (OR = 3.38, 95% CI: 1.59-7.14). In addition, referral marketers also contributed to making the participants more likely to smoke e-cigarettes (OR = 2.68, 95% CI: 1.03-6.95). Attractive color and free sample of e-cigarettes were also found to be the motivated factors associated with smoking behaviour among youth and adolescents.

CONCLUSIONS

New policies should be considered to oppose the impact of youth-oriented e-cigarette advertisements which include regulating and restricting e-cigarette advertisements on social media, as well as through referral marketers.

Use of tobacco and e-cigarettes among youth in Great Britain in 2022: Analysis of a cross-sectional survey

INTRODUCTION

Although e-cigarettes can be an effective form of nicotine substitution for adults attempting to quit smoking, their use among children and young people is a concern. Accurate data about this are needed to inform debates over policy and regulation in the UK and elsewhere.

METHODS

Using data from an online survey of 2613 youth aged 11-18 years, conducted by the market research company YouGov in March 2022, we present prevalence estimates of e-cigarette and tobacco use. We use logistic regression models to assess differences in e-cigarette use, tobacco use and use of disposable e-cigarettes across a range of covariates including age, sex, tobacco smoking status, social class, and country.

RESULTS

Among the 18.0% of those surveyed who reported ever having smoked a cigarette, 83.9% were not regular (at least once per week) smokers and 16.1% were (15.1% and 2.9% of the total sample, respectively). Among the 19.2% of those surveyed who had ever used an e-cigarette, 79.2% were not regular users, while 20.8% were (15.2% and 4.0% of the total sample, respectively). Regular e-cigarette use was more common than regular tobacco smoking (4.0% vs 2.9%). E-cigarette use was more common among those who also smoked tobacco, with 9.0% of never e-cigarette users ever smoking tobacco, compared with 89.4% of regular e-cigarette users. Both smoking and e-cigarette use were associated with increasing age and use by others within the home, but not with social class. Use of disposable e-cigarettes was reported by 53.8% of those who have ever used an e-cigarette, and more common among females than males.

CONCLUSIONS

Regular e-cigarette use is now more common than smoking in children and youth, though the majority of this is among those who have also smoked tobacco. Measures to reduce the appeal of both e-cigarettes and tobacco to children and young people are warranted.

The prevalence of electronic cigarettes vaping globally: a systematic review and meta-analysis

Background

The purpose of this systematic review study was to determine the national, regional, and global prevalence of electronic cigarettes (e-cigarettes) vaping.

Method

The articles were searched in July 2020 without a time limit in Web of Science (ISI), Scopus, PubMed, and Ovid-MEDLINE. At first, the titles and abstracts of the articles were reviewed, and if they were appropriate, they entered the second stage of screening. In the second stage, the whole articles were reviewed and articles that met the inclusion criteria were selected. In this study, search, selection of studies, qualitative evaluation, and data extraction were performed by two authors independently, and any disagreement between the two authors was reviewed and corrected by a third author.

Results

In this study, the lifetime and current prevalence of e-cigarettes vaping globally were 23% and 11%, respectively. Lifetime and current prevalence of e-cigarettes vaping in women were 16% and 8%, respectively. Also, lifetime and current prevalence of e-cigarettes vaping in men were 22% and 12%, respectively. In this study, the current prevalence of e-cigarettes vaping in who had lifetime smoked conventional cigarette was 39%, and in current smokers was 43%. The lifetime prevalence of e-cigarettes vaping in the Continents of America, Europe, Asia, and Oceania were 24%, 26%, 16%, and 25%, respectively. The current prevalence of e-cigarettes vaping in the Continents of America, Europe, Asia, and Oceania were 10%, 14%, 11%, and 6%, respectively.

Conclusions

Based on the results of this study, it can be concluded that the popularity of e-cigarettes is increasing globally. Therefore, it is necessary for countries to have more control over the consumption and distribution of e-cigarettes, as well as to formulate the laws prohibiting about the e-cigarettes vaping in public places. There is also a need to design and conduct information campaigns to increase community awareness about e-cigarettes vaping.

A Close Look at Vaping in Adolescents and Young Adults in the United States

Vaping by adolescents and young adults is a legitimate concern as there is a risk that some may start smoking and that electronic cigarette (EC) use may have adverse effects in the developing lungs of adolescents. This commentary provides updated information on vaping patterns among adolescents and young adults in the United States, as well as the impact of EC usage on respiratory health. EC use has surged greatly among high school students and young adults over the last decade but fortunately has declined significantly since its peak in 2019. During the same time period, smoking rates have constantly fallen to new low record levels. These trends argue against EC use as a gateway to smoking. Most EC usage is infrequent and unlikely to increase a person's risk of negative health consequences. Furthermore, the majority of EC usage has happened among those who have previously smoked. There is a dearth of data on the long-term health implications of EC usage in adolescents and young adults. We do not know whether short-term or intermittent use of EC in youth can lead to negative health outcomes in adulthood, and long-term high-quality studies in well-defined groups are needed. Although vaping has been linked to respiratory symptoms, they tend to be transient and of uncertain significance. This commentary provides up-to-date information so health care providers can give objective and responsible medical advice on EC usage.

E-cigarette use, opinion about harmfulness and addiction among university students in Bratislava, Slovakia

OBJECTIVES

The study aimed to investigate the use of electronic cigarettes (EC) among medical students, their knowledge and beliefs (opinion about harmfulness and addiction potential) on ECs, perceptions of the risk, as well as to assess the type of education and cessation training they received during their study at Faculty of Medicine, Comenius University in Bratislava, Slovakia.

METHODS

This cross-sectional, anonymous online e-mailed survey was conducted among medical students via the Study Department by sending e-mails containing the survey link. Participants completed the online questionnaire adapted from the American Survey on Tobacco and Alternative Tobacco Products. It included questions about the personal use of EC, perceptions about the harms and their role in disease causation, education and cessation training, and practices related to conventional cigarettes (CC), EC, and alternative tobacco products (ATP). The e-mailed questionnaire filled in 577 medical students (71.9% women) from Comenius University in Bratislava, the average age was 23 ± 2 years. The sample comprised 486 (84.2%) Slovak and 91 (15.8%) foreign students. The data were analysed using the Statistical Package for Social Science (SPSS) version 25.

RESULTS

There were 385 (66.7%) non-smokers, 111 (19.3%) ex-smokers and 81 (14%) current smokers in the study sample. EC currently use 13.5% of medical students, with a statistically significant intersexual difference (22.2% males vs. 10.12% females; OR = 2.53, 95% CI: 1.55-4.13), more foreign students than Slovak students (24.2% vs. 11.52%; OR = 2.44, 95% CI: 1.41-4.26), more smokers of conventional cigarettes than non-smokers (46.9% vs. 8.06%; OR = 10.07, 95% CI: 5.85-17.34). EC seems to be less harmful to 59.97% of students, mostly in the age group ≤ 24 (61.76% vs. 51.49%; OR = 1.46, 95% CI: 1.03-2.07), 41.25% of students consider EC to be less addictive, 55.6% think they do not get enough education on EC during their medical study.

CONCLUSION

The results overall show the high consumption of tobacco products and the lack of knowledge and awareness among medical students, future health care providers. In health promotion and disease prevention, they should serve as a model for their patients and for the general public as well. Our study emphasizes the need for intervention in this field at medical faculties and for support of further monitoring in Slovakia and other countries and draws attention to the ongoing lack of EC regulation.

Is Adolescent E-Cigarette Use Associated With Subsequent Smoking? A New Look

INTRODUCTION

Prospective studies have consistently reported a strong association between e-cigarette use and subsequent cigarette smoking, but many failed to adjust for important risk factors.

METHODS

Using longitudinal data from the Population Assessment of Tobacco and Health (PATH) Study, we employed multivariable logistic regressions to assess the adolescent vaping-to-smoking relationship, with four regressions (Models 1-4) sequentially adding more risk factors.Our sample included all waves (waves 1-5) of the PATH Study.

RESULTS

The association between ever e-cigarette use and subsequent cigarette smoking decreased substantially in magnitude when adding more control variables, including respondents' sociodemographic characteristics, exposure to tobacco users, cigarette susceptibility, and behavioral risk factors. Using the most recent data (waves 4-4.5 and waves 4.5-5), this association was not significant in the most complete model (Model 4). Using wave 4.5-5 data, the adjusted odds ratio (aOR) for ever e-cigarette use at initial wave and subsequent past 12-month smoking declined from 4.07 (95% confidence interval [CI, 2.86-5.81) in Model 1, adjusting only for sociodemographic characteristics, to 1.35 (95% CI, 0.84-2.16) in Model 4, adjusting for all potential risk factors. Similarly, the aOR of ever e-cigarette use and past 30-day smoking at wave 5 decreased from 3.26 (95% CI, 1.81-5.86) in Model 1 to 1.21 (95% CI, 0.59-2.48) with all covariates (Model 4).

CONCLUSIONS

Among adolescent never cigarette smokers, those who had ever used e-cigarettes at baseline, compared with never e-cigarette users, exhibited modest or non-significant increases in subsequent past 12-month or past 30-day smoking when adjusting for behavioral risk factors.

Electronic Cigarette Vaping Did Not Enhance the Neural Process of Working Memory for Regular Cigarette Smokers

Background

Electronic cigarettes (e-cigs) as substitute devices for regular tobacco cigarettes (r-cigs) have been increasing in recent times. We investigated neuronal substrates of vaping e-cigs and smoking r-cigs from r-cig smokers.

Methods

Twenty-two r-cig smokers made two visits following overnight smoking cessation. Functional magnetic resonance imaging (fMRI) data were acquired while participants watched smoking images. Participants were then allowed to smoke either an e-cig or r-cig until satiated and fMRI data were acquired. Their craving levels and performance on the Montreal Imaging Stress Task and a 3-back alphabet/digit recognition task were obtained and analyzed using two-way repeated-measures analysis of variance. Regions-of-interest (ROIs) were identified by comparing the abstained and satiated conditions. Neuronal activation within ROIs was regressed on the craving and behavioral data separately.

Results

Craving was more substantially reduced by smoking r-cigs than by vaping e-cigs. The response time (RT) for the 3-back task was significantly shorter following smoking r-cigs than following vaping e-cigs (interaction: F (1, 17) = 5.3, p = 0.035). Neuronal activations of the right vermis (r = 0.43, p = 0.037, CI = [-0.05, 0.74]), right caudate (r = 0.51, p = 0.015, CI = [0.05, 0.79]), and right superior frontal gyrus (r = −0.70, p = 0.001, CI = [−0.88, −0.34]) were significantly correlated with the RT for the 3-back task only for smoking r-cigs.

Conclusion

Our findings suggest that insufficient satiety from vaping e-cigs for r-cigs smokers may be insignificant effect on working memory function.

E-cigarette use and combustible tobacco cigarette smoking uptake among non-smokers, including relapse in former smokers: umbrella review, systematic review and meta-analysis

OBJECTIVE

To review and summarise the current evidence on the uptake of combustible cigarette smoking following e-cigarette use in non-smokers-including never-smokers, people not currently smoking and past smokers-through an umbrella review, systematic review and meta-analysis.

DESIGN

Umbrella review, systematic review and meta-analysis.

DATA SOURCES

PubMed, Scopus, Web of Science, PsychINFO (Ovid), Medline (Ovid) and Wiley Cochrane Library up to April 2020.

RESULTS

Of 6225 results, 25 studies of non-smokers-never, not current and former smokers-with a baseline measure of e-cigarette use and an outcome measure of combustible smoking uptake were included. All 25 studies found increased risk of smoking uptake with e-cigarette exposure, although magnitude varied substantially. Using a random-effects model, comparing e-cigarette users versus non-e-cigarette users, among never-smokers at baseline the OR for smoking initiation was 3.25 (95% CI 2.61 to 4.05, I2 85.7%) and among non-smokers at baseline the OR for current smoking was 2.87 (95% CI 1.97 to 4.19, I2 90.1%). Among former smokers, smoking relapse was higher in e-cigarette users versus non-users (OR=2.40, 95% CI 1.50 to 3.83, I2 12.3%).

CONCLUSIONS

Across multiple settings, non-smokers who use e-cigarettes are consistently more likely than those avoiding e-cigarettes to initiate combustible cigarette smoking and become current smokers. The magnitude of this risk varied, with an average of around three times the odds. Former smokers using e-cigarettes have over twice the odds of relapse as non-e-cigarettes users. This study is the first to our knowledge to review and pool data on the latter topic.

PROSPERO REGISTRATION NUMBER

CRD42020168596.

Cigarette smoking and e-cigarette use among university students in Queensland, Australia and New Zealand: results of two cross-sectional surveys

OBJECTIVES

Examine the patterns of cigarette smoking and e-cigarette use (vaping), the perceived harm of e-cigarettes compared with tobacco cigarettes, and associations between smoking and vaping with student characteristics.

DESIGN

Cross-sectional studies.

SETTING

The University of Queensland (UQ), Australia and eight New Zealand (NZ) universities.

PARTICIPANTS

Students at UQ: 4957 (70.8% aged <25 years, 63.0% women) and NZ: 1854 (82.5% aged <25 years, 60.1% women).

METHODS

Χ2 tests compared smoking by age and gender, and vaping by age, gender and smoking status. Two-sided p<0.05 was considered significant and 95% CIs reported where appropriate. Multinomial logistic regression examined associations between smoking and vaping (exclusive smoking, exclusive vaping, dual use and non-use) with age, gender and student type (domestic vs international).

RESULTS

Smoking (UQ vs NZ, 95% CI): ever 45.2% (43.8% to 46.6%) vs 50.0% (47.7% to 52.3%), current 8.9% (8.1% to 9.7%) vs 10.4% (9.1% to 11.9%) and daily 5.2% (4.6% to 5.8%) vs 5.6% (4.6% to 6.7%), and not smoking in indoor 98.3% vs 87.7% or outdoor smoke-free spaces 83.8% vs 65.3%.Vaping (UQ vs NZ, 95% CI): ever 20.9% (19.8% to 22.1%) vs 37.6% (35.4% to 39.9%), current 1.8% (1.5% to 2.2%) vs 6.5% (5.4% to 7.7%) and daily 0.7% (0.5% to 1.0%) vs 2.5% (1.9% to 3.4%), and not vaping in indoor 91.4% vs 79.6% or outdoor smoke-free spaces 84.4% vs 71.3%. Of respondents, 71.7% (70.3% to 73.2%) vs 75.3% (72.9% to 77.6%) perceived e-cigarettes as less harmful than tobacco cigarettes.Men were more likely than women to smoke and vape, and to believe that e-cigarettes are less harmful. Regression models containing all predictors for smoking and vaping were significant and the effect of gender was significant for dual use, exclusive smoking and exclusive vaping (all p<0.01). Men had higher odds for smoking, vaping or dual use.

CONCLUSIONS

Results suggest significant differences in patterns of smoking and vaping of university students in Australia and NZ, and a strong influence of gender on smoking and vaping.

Factors associated with electronic cigarettes use among adolescents in Jakarta, Indonesia

Purpose

This study aimed to examine factors associated with electronic cigarette use among adolescents aged 15–19 in Jakarta, Indonesia.

Design/methodology/approach

The study was a school-based survey involving 1,318 students from 14 high schools in Jakarta. A multistage cluster sampling methodology was used. The authors used the chi-square test and multiple logistic regression to examine the association between electronic cigarette use and sociodemographic, social influences, health risk perceptions, availability, affordability and conventional cigarette smoking status.

Findings

Overall, 6.3% of females and 29% of males reported ever having used electronic cigarettes. Electronic cigarette use was independently associated with sex, school locations, conventional cigarette smoking status, peer use, availability and perceptions that electronic cigarettes aid conventional cigarette smoking cessation. Compared with non-smokers, lifetime (AOR: 8.740, 95% CI: 5.126–14.901) and current conventional cigarette smokers (AOR: 18.380, 95% CI: 10.577–31.938) were more likely to use electronic cigarettes.

Social implications

The use of electronic cigarettes among adolescents was considerably high in this study. Therefore, the tobacco control policy should be extended to regulate the marketing and use of all types of tobacco products and not just conventional cigarettes.

Originality/value

The study explored beyond individual lifestyle factors that contributed to electronic cigarette use in Indonesia such as affordability, school locations and availability of electronic cigarettes. These issues have not been specifically discussed in previous studies.

Investigating the added value of biomarkers compared with self-reported smoking in predicting future e-cigarette use: Evidence from a longitudinal UK cohort study

Biomarkers can be used to assess smoking behaviour more accurately and objectively than self-report. This study assessed the association between cotinine (a biomarker of smoke exposure) and later e-cigarette use among a population who were unexposed to e-cigarettes in youth. Young people in the Avon Longitudinal Study of Parents and Children took part in the study. We observed associations between cotinine at 15 years (measured between 2006 and 2008 before the wide availability of e-cigarettes) and self-reported ever use of e-cigarettes at 22 (measured between 2014 and 2015 when e-cigarettes were widely available) using logistic regression. A range of potential confounders were adjusted for (age, sex, body mass index, alcohol use and passive smoke exposure). Additionally, we adjusted for the young people's self-reported smoking status/history to explore potential misreporting and measurement error. In a sample of N = 1,194 young people, cotinine levels consistent with active smoking at 15 years were associated with increased odds of e-cigarette ever use at 22 years (Odds Ratio [OR] = 7.24, 95% CI 3.29 to 15.93) even when self-reported active smoking status at age 16 (OR = 3.14, 95% CI 1.32 to 7.48) and latent classes of smoking behaviour from 14 to 16 (OR = 2.70, 95% CI 0.98 to 7.44) were included in the model. Cotinine levels consistent with smoking in adolescence were strongly associated with increased odds of later e-cigarette use, even after adjusting for reported smoking behaviour at age 16 and smoking transitions from 14 to 16.

Electronic cigarette use among university students aged 18-24 years in New Zealand: results of a 2018 national cross-sectional survey

OBJECTIVES

To examine electronic cigarette use, reasons for use and perceptions of harm among university students.

DESIGN

Cross-sectional study.

SETTING

University students across New Zealand.

METHODS

We analysed data from a 2018 cross-sectional survey of university students, weighted to account for undersampling and oversampling by gender and university size. χ² tests were used to compare e-cigarette use, reasons for use and perceptions of harm by age, gender, ethnicity and cigarette smoking.

PARTICIPANTS

The sample comprised 1476 students: 62.3% aged 18-20 years, 37.7% aged 21-24 years; 38.6% male, 61.4% female; 7.9% Māori and 92.1% non-Māori.

RESULTS

40.5% of respondents (95% CI 37.9 to 43.1) reported ever, 6.1% (4.9-7.4) current and 1.7% (1.1-2.5) daily use. Regardless of frequency, 11.5% of vapers had vaped daily for ≥1 month, 70.2% of whom used nicotine-containing devices; 80.8% reported not vaping in indoor and 73.8% in outdoor smoke-free spaces. Among ever vapers, curiosity (67.4%), enjoyment (14.4%) and quitting (2.4%) were common reasons for vaping. 76.1% (73.4-78.7) of respondents believed e-cigarettes were less harmful than cigarettes.More males than females reported vaping (ever, current, daily and daily for ≥1 month), nicotine use and belief that e-cigarettes were less harmful than cigarettes. More participants aged 18-20 years reported not vaping in outdoor smoke-free spaces, vaping out of curiosity and belief that e-cigarettes were less harmful than cigarettes, while more participants aged 21-24 years vaped daily for ≥1 month and for enjoyment. More Māori than non-Māori ever vaped. More cigarette smokers than non-smokers vaped (ever, current, daily and daily for ≥1 month), used nicotine and vaped to quit, while more non-smokers did not vape in smoke-free spaces and vaped out of curiosity.

CONCLUSIONS

Our results suggest high prevalence of e-cigarette ever and current use, particularly among males and smokers. Many vaped out of curiosity and perceived e-cigarettes as less harmful than cigarettes.

Patterns of E-Cigarette Use Among Youth and Young Adults: Review of the Impact of E-Cigarettes on Cigarette Smoking

There is concern that e-cigarette use among youth and young adults (YAs) may lead to future cigarette or other combustible tobacco product use. A synthesis of the literature on this topic is needed because existing longitudinal studies are limited in number and not consistent in their conclusions. We conducted a search in PubMed through December 31, 2017 for peer-reviewed studies related to e-cigarette patterns of use. Of 588 relevant studies, 26 had a youth or YA sample, were longitudinal in design, and assessed e-cigarette use at baseline and cigarette smoking at follow-up. Most studies followed a sample over time and compared cigarette smoking at follow-up between baseline e-cigarette users and nonusers. Other studies examined the difference at follow-up in cigarette smoking status among smokers according to e-cigarette use at baseline. Results suggest that, among never smokers, e-cigarette use is associated with the future (6 months to 2.5 years) cigarette trial; however, firm conclusions cannot be drawn because of limitations including small sample size, measurement of experimental use (ie, ever use, past 30-day use) rather than established use, and inadequate controls for potentially confounding variables. Conclusions also cannot be drawn from studies examining the impact of e-cigarette use among smokers due to the limited number of studies and additional limitations. A comprehensive understanding of this literature is needed to inform policy makers and consumers for evidence-based decision-making and to guide future research on e-cigarette use among youth and young adults.

IMPLICATIONS

The present article provides a review of the impact of e-cigarette use on subsequent cigarette smoking among youth and YAs. Studies presented here suggest that e-cigarette use among nonsmokers is associated with subsequent cigarette smoking, but study designs are subject to numerous limitations. Future research should focus on addressing the characteristics that put youth and YAs at the risk of using either product and how appeal and accessibility of these products are related to product use in order to inform future policy-making.

Association between changes in harm perceptions and e-cigarette use among current tobacco smokers in England: a time series analysis

BACKGROUND

There is a decreasing trend in the proportion of individuals who perceive e-cigarettes to be less harmful than conventional cigarettes across the UK, Europe and the US. It is important to assess whether this may influence the use of e-cigarettes. We aimed to estimate, using a time series approach, whether changes in harm perceptions among current tobacco smokers have been associated with changes in the prevalence of e-cigarette use in England, with and without stratification by age, sex and social grade.

METHODS

Respondents were from the Smoking Toolkit Study, which involves monthly cross-sectional household surveys of individuals aged 16+ years in England. Data were aggregated monthly on ~ 300 current tobacco smokers between 2014 and 2019. The outcome variable was the prevalence of e-cigarette use. The explanatory variable was the proportion of smokers who endorsed the belief that e-cigarettes are less harmful than combustible cigarettes. Covariates were cigarette (vs. non-cigarette combustible) current smoking prevalence, past-year quit attempt prevalence and national smoking mass media expenditure. Unadjusted and adjusted autoregressive integrated moving average with exogeneous variables (ARIMAX) models were fitted.

RESULTS

For every 1% decrease in the mean prevalence of current tobacco smokers who endorsed the belief that e-cigarettes are less harmful than combustible cigarettes, the mean prevalence of e-cigarette use decreased by 0.48% (βadj = 0.48, 95% CI = 0.25-0.71, p < .001). Marginal age and sex differences were observed, whereby significant associations were observed in older (but not in young) adults and in men (but not in women). No differences by social grade were detected.

CONCLUSIONS

Between 2014 and 2019 in England, at the population level, monthly changes in the prevalence of accurate harm perceptions among current tobacco smokers were strongly associated with changes in e-cigarette use.

Is e-cigarette use in non-smoking young adults associated with later smoking? A systematic review and meta-analysis

OBJECTIVE

The aim of this review was to investigate whether e-cigarette use compared with non-use in young non-smokers is associated with subsequent cigarette smoking.

DATA SOURCES

PubMed, Embase, Web of Science, Wiley Cochrane Library databases, and the 2018 Society for Research on Nicotine and Tobacco and Society for Behavioural Medicine conference abstracts.

STUDY SELECTION

All studies of young people (up to age 30 years) with a measure of e-cigarette use prior to smoking and an outcome measure of smoking where an OR could be calculated were included (excluding reviews and animal studies).

DATA EXTRACTION

Independent extraction was completed by multiple authors using a preprepared extraction form.

DATA SYNTHESIS

Of 9199 results, 17 studies were included in the meta-analysis. There was strong evidence for an association between e-cigarette use among non-smokers and later smoking (OR: 4.59, 95% CI: 3.60 to 5.85) when the results were meta-analysed in a random-effects model. However, there was high heterogeneity (I2 =88%).

CONCLUSIONS

Although the association between e-cigarette use among non-smokers and subsequent smoking appears strong, the available evidence is limited by the reliance on self-report measures of smoking history without biochemical verification. None of the studies included negative controls which would provide stronger evidence for whether the association may be causal. Much of the evidence also failed to consider the nicotine content of e-liquids used by non-smokers meaning it is difficult to make conclusions about whether nicotine is the mechanism driving this association.

Effects of a Nicotine Fact Sheet on Perceived Risk of Nicotine and E-Cigarettes and Intentions to Seek Information About and Use E-Cigarettes

We examined how a nicotine fact sheet influenced smokers’ beliefs about nicotine and electronic cigarettes (e-cigarettes), a potentially less harmful alternative to conventional cigarettes. In an exploratory online experiment, 756 US adult current and recent former smokers (quit in the past 2 years) were randomized to view a nicotine fact sheet or control messages (bottled water ads). Effects of the nicotine fact sheet on perceived nicotine addictiveness, nicotine risk, comparative risk of e-cigarettes, and dual use intentions were analyzed using log-Poisson regression with robust error. Linear regression analyzed effects on perceived absolute risk and switching and information seeking intentions about e-cigarettes. Compared to control, the nicotine fact sheet doubled the probability of disagreeing that nicotine is the main cause of smoking-related disease (26.2% vs. 12.7%, RR = 2.06, 95% CI = 1.51, 2.82, p < 0.001). However, nearly three quarters of participants viewing the nicotine fact sheet still thought that nicotine is the main cause of smoking-related disease. The nicotine fact sheet increased smokers’ intentions to seek information about e-cigarettes (b = 0.45, 95% CI = 0.15, 0.74, p = 0.003). We did not find evidence suggesting unintended consequences of the nicotine fact sheet on smokers’ e-cigarettes risk perceptions or use intentions (e.g., increased dual use intentions or reduced absolute e-cigarette risk perception).

Evidence that an intervention weakens the relationship between adolescent electronic cigarette use and tobacco smoking: a 24-month prospective study

BACKGROUND

The electronic cigarette (e-cigarette) use to subsequent smoking relationship in adolescents has received much attention. Whether an intervention to reduce smoking initiation attenuated this relationship was assessed.

METHOD

Data were from 3994 adolescent never smokers (aged 13-14 years at baseline) as part of a cluster randomised controlled trial. Self-report measures of smoking, e-cigarette use and covariates were assessed and used to predict ever smoked cigarettes, any recent tobacco smoking and regularly smoked cigarettes at 24-month follow-up.

RESULTS

Baseline ever use of e-cigarettes was associated with ever smoked cigarettes (OR=4.03, 95% CI 3.33 to 4.88; controlling for covariates, OR=2.78, 95% CI 2.20 to 3.51), any recent tobacco smoking (OR=3.38, 95% CI 2.72 to 4.21; controlling for covariates, OR=2.17, 95% CI 1.76 to 2.69) and regularly smoked cigarettes (OR=3.60, 95% CI 2.35 to 5.51; controlling for covariates, OR=1.27, 95% CI 1.17 to 1.39) at follow-up. For ever smoked cigarettes only, the impact of e-cigarette use was attenuated in the intervention (OR=1.83) compared with control (OR=4.53) condition. For ever smoked cigarettes and any recent tobacco smoking, the impact of e-cigarette use was attenuated among those with friends who smoked (OR=2.05 (ever smoked); 1·53 (any tobacco use)) compared with those without friends who smoked (OR=3.32 (ever smoked); 2·17 (any tobacco use)).

CONCLUSIONS

This is one of the first studies to show that e-cigarette use was robustly associated with measures of smoking over 24 months and the first to show an intervention to attenuate the relationship. Further research with a broader age range of adolescents is required.

Immunological and pathological effects of electronic cigarettes

Electronic cigarettes (E-cigarettes) are considered a preferable alternative to conventional cigarettes due to the lack of combustion and the absence of tobacco-specific toxicants. E-cigarettes have rapidly gained in popularity in recent years amongst both existing smokers and previous non-smokers. However, a growing literature demonstrates that E-cigarettes are not as safe as generally believed. Here, we discuss the immunological, and other, deleterious effects of E-cigarettes on a variety of cell types and host defence mechanisms in humans and in murine models. We review not only the effects of complete E-cigarette liquids, but also each of the main components-nicotine, humectants and flavourings. This MiniReview thus highlights the possible role of E-cigarettes in the pathogenesis of disease and raises awareness of the potential harm that E-cigarettes may cause.

Is adolescent e-cigarette use associated with smoking in the United Kingdom?: A systematic review with meta-analysis

INTRODUCTION

Though smoking is a public health problem the use of e-cigarettes has been associated with a reduction in smoking in developed countries. However, public health experts have raised concerns about the association of e-cigarette use with an increase in traditional cigarette smoking in adolescents. Review-level evidence is generally supportive of this concern, but as it is mainly based on studies from the USA we investigated if e-cigarette use is associated with traditional cigarette smoking in adolescents (aged 10–19 years) in the UK.

METHODS

We conducted a systematic review of empirical studies. Databases (PubMed, Medline via ProQuest, CINAHL and SCOPUS) were searched between January 2005 and May 2018 using search terms based on the concepts: adolescents, traditional cigarette smoking, e-cigarettes, and UK. Using pre-defined inclusion and exclusion criteria, a total of eight studies (involving 73076 adolescents) were included in this review. Three of the included studies were eligible to be combined in a meta-analysis. The CASP appraisal tool was used to assess study quality while risk of bias was assessed using ROBINS-I.

RESULTS

Studies included in the meta-analysis showed that adolescents who use e-cigarettes are up to six times more likely to smoke traditional cigarettes. Furthermore, results showed that traditional cigarette smoking can also precede e-cigarette use in adolescents and there was increased likelihood of an increase in initial product use (e-cigarette or traditional cigarette) when the alternate product was initiated.

CONCLUSIONS

Public health policy makers in the UK still need clear conclusions about the effects and safety of e-cigarettes.

Investigating gateway effects using the PATH study

BACKGROUND

A recent meta-analysis of nine cohort studies in youths reported that baseline ever e-cigarette use strongly predicted cigarette smoking initiation in the next 6-18 months, with an adjusted odds ratio of 3.62 (95% confidence interval 2.42-5.41).  A recent review of e-cigarettes agreed there was substantial evidence for this "gateway effect".  However, the number of confounders considered in the studies was limited, so we investigated whether the effect might have resulted from inadequate adjustment, using Waves 1 and 2 of the Population Assessment of Tobacco and Health study.

METHODS

Our main analyses considered Wave 1 never cigarette smokers who, at Wave 2, had information available on smoking initiation.  We constructed a propensity score for ever e-cigarette use from Wave 1 variables, using this to predict ever cigarette smoking.  Sensitivity analyses accounted for use of other tobacco products, linked current e-cigarette use to subsequent current smoking, or used propensity scores for ever smoking or ever tobacco product use as predictors.  We also considered predictors using data from both waves to attempt to control for residual confounding from misclassified responses.

RESULTS

Adjustment for propensity dramatically reduced the unadjusted odds ratio (OR) of 5.70 (4.33-7.50) to 2.48 (1.85-3.31), 2.47 (1.79-3.42) or 1.85 (1.35-2.53), whether adjustment was made as quintiles, as a continuous variable or for the individual variables.  Additional adjustment for other tobacco products reduced this last OR to 1.59 (1.14-2.20).  Sensitivity analyses confirmed adjustment removed most of the gateway effect.  Control for residual confounding also reduced the association.

CONCLUSIONS

We found that confounding is a major factor, explaining most of the observed gateway effect.  However, our analyses are limited by small numbers of new smokers considered and the possibility of over-adjustment if taking up e-cigarettes affects some predictor variables.  Further analyses are intended using Wave 3 data which should avoid these problems.

Investigating gateway effects using the PATH study

BACKGROUND

A recent meta-analysis of nine cohort studies in youths reported that baseline ever e-cigarette use strongly predicted cigarette smoking initiation in the next 6-18 months, with an adjusted odds ratio of 3.62 (95% confidence interval 2.42-5.41).  A recent review of e-cigarettes agreed there was substantial evidence for this "gateway effect".  However, the number of confounders considered in the studies was limited, so we investigated whether the effect might have resulted from inadequate adjustment, using Waves 1 and 2 of the Population Assessment of Tobacco and Health study.

METHODS

Our main analyses considered Wave 1 never cigarette smokers who, at Wave 2, had information available on smoking initiation.  We constructed a propensity score for ever e-cigarette use from Wave 1 variables, using this to predict ever cigarette smoking.  Sensitivity analyses accounted for use of other tobacco products, linked current e-cigarette use to subsequent current smoking, or used propensity scores for ever smoking or ever tobacco product use as predictors.  We also considered predictors using data from both waves to attempt to control for residual confounding from misclassified responses.

RESULTS

Adjustment for propensity dramatically reduced the unadjusted odds ratio (OR) of 5.70 (4.33-7.50) to 2.48 (1.85-3.31), 2.47 (1.79-3.42) or 1.85 (1.35-2.53), whether adjustment was made as quintiles, as a continuous variable or for the individual variables.  Additional adjustment for other tobacco products reduced this last OR to 1.59 (1.14-2.20).  Sensitivity analyses confirmed adjustment removed most of the gateway effect.  Control for residual confounding also reduced the association.

CONCLUSIONS

We found that confounding is a major factor, explaining most of the observed gateway effect.  However, our analyses are limited by small numbers of new smokers considered and the possibility of over-adjustment if taking up e-cigarettes affects some predictor variables.  Further analyses are intended using Wave 3 data which should avoid these problems.

Exclusive versus dual use of tobacco and electronic cigarettes among adolescents in Poland, 2010-2016

Globally, electronic cigarette (e-cigarette) use among adolescents has increased, along with concerns about potential health implications from exclusive and concurrent tobacco and e-cigarette use (i.e., "dual use"). This study used data from a cross-sectional survey administered to 5708 students aged 15-19 in secondary and technical schools throughout two regions of Poland. Data from 2010-2011 (n = 1760); 2013-2014 (n = 1970) and 2015-2016 (n = 1978) were analyzed to assess changes in use of cigarettes and e-cigarettes from 2010-2016, and correlates of exclusive and dual use, daily use, and intensity of product use from 2013-2016. In this sample, e-cigarette trial and past 30-day exclusive e-cigarette use significantly increased over time (2010-2011: 2%; 2013-2014: 8%; 2015-2016: 11% (p < .05)). Dual use increased from 2010-2011 (4%) to 2013-2014 only (23%, p < .05); and remained stable from 2013-2014 to 2015-2016 (24%, p = .60). Most dual users reported using cigarettes before trying e-cigarettes (82% in 2013-2014, 76% in 2015-2016). Analyses comparing dual users to exclusive users showed significant differences in frequency and intensity of product use, similar findings were observed within dual users. Following the introduction of e-cigarettes, both total tobacco use and total cigarette use increased. Among youth in Poland, e-cigarettes do not seem to replace conventional cigarettes, but instead contribute to a more diverse array of available products from which youth can experiment.

Electronic cigarettes: a task force report from the European Respiratory Society

There is a marked increase in the development and use of electronic nicotine delivery systems or electronic cigarettes (ECIGs). This statement covers electronic cigarettes (ECIGs), defined as "electrical devices that generate an aerosol from a liquid" and thus excludes devices that contain tobacco. Database searches identified published articles that were used to summarise the current knowledge on the epidemiology of ECIG use; their ingredients and accompanied health effects; second-hand exposure; use of ECIGs for smoking cessation; behavioural aspects of ECIGs and social impact; in vitro and animal studies; and user perspectives.ECIG aerosol contains potentially toxic chemicals. As compared to conventional cigarettes, these are fewer and generally in lower concentrations. Second-hand exposures to ECIG chemicals may represent a potential risk, especially to vulnerable populations. There is not enough scientific evidence to support ECIGs as an aid to smoking cessation due to a lack of controlled trials, including those that compare ECIGs with licenced stop-smoking treatments. So far, there are conflicting data that use of ECIGs results in a renormalisation of smoking behaviour or for the gateway hypothesis. Experiments in cell cultures and animal studies show that ECIGs can have multiple negative effects. The long-term effects of ECIG use are unknown, and there is therefore no evidence that ECIGs are safer than tobacco in the long term. Based on current knowledge, negative health effects cannot be ruled out.

Considerations related to vaping as a possible gateway into cigarette smoking: an analytical review

Background: Toxicant levels are much lower in e-cigarettes than cigarettes. Therefore, introducing e-cigarettes into the market seems likely to reduce smoking-related diseases (SRD). However, vaping might provide a gateway into cigarette smoking for those who otherwise would never have smoked, a concern fuelled by cohort studies showing vaping predicts subsequent smoking initiation in young people. Methods: In this discussion paper, we consider various aspects of the gateway issue in youths. We provide a descriptive critical review of results from prospective studies relating to the gateway effect and the extent to which the studies considered other potential confounding variables associated with smoking initiation. We then estimate the effects of omitting a confounding variable, or misclassifying it, on the association between vaping and subsequent smoking initiation, and determine how the prevalence of smoking might be affected by any true gateway effects of vaping. Finally, we examine trends in e-cigarette and smoking prevalence in youths based on national surveys. Results: First, we demonstrate that although studies report that vaping significantly predicts smoking initiation following adjustment for various other predictors, the sets of predictors considered are quite incomplete. Furthermore, no study considered residual confounding arising from inaccurate measurement of predictors. More precise adjustment may substantially reduce the association. Second, we show any true gateway effect would likely affect smoking prevalence only modestly. Third, we show smoking prevalence in U.S. and U.K. youths in 2014-2016 declined somewhat faster than predicted by the preceding trend; a substantial gateway effect suggests the opposite. Finally, we argue that even if some gateway effect exists, introducing e-cigarettes still likely reduces SRDs. Conclusions: Given that the existence of any true gateway effect in youth is not yet clearly demonstrated the population health impact of introducing e-cigarettes is still likely to be beneficial.

Considerations related to vaping as a possible gateway into cigarette smoking: an analytical review

Background: Toxicant levels are much lower in e-cigarettes than cigarettes. Therefore, introducing e-cigarettes into the market seems likely to reduce smoking-related diseases (SRD). However, vaping might provide a gateway into cigarette smoking for those who otherwise would never have smoked, a concern fueled by cohort studies showing vaping predicts subsequent smoking initiation in young people. Methods: In this discussion paper, we consider various aspects of the gateway issue in youths. We provide a descriptive critical review of results from prospective studies relating to the gateway effect and the extent to which the studies considered other potential confounding variables associated with smoking initiation.  We then estimate the effects of omitting a confounding variable, or misclassifying it, on the association between vaping and subsequent smoking initiation, and determine how the prevalence of smoking might be affected by any true gateway-in effects of vaping. Finally, we examine trends in e-cigarette and smoking prevalence in youths based on national surveys. Results:  First, we demonstrate that although studies report that vaping significantly predicts smoking initiation following adjustment for various other predictors, the sets of predictors considered are quite incomplete. Furthermore, no study considered residual confounding arising from inaccurate measurement of predictors. More precise adjustment may substantially reduce the association. Second, we show any true gateway effect would likely affect smoking prevalence only modestly. Third, we show smoking prevalence in U.S. and U.K. youths in 2014-2016 declined somewhat faster than predicted by the preceding trend; a substantial gateway effect suggests the opposite. Finally, we argue that even if some gateway effect exists, introducing e-cigarettes still likely reduces SRDs. Conclusions: We have shown that the existence of any true gateway-in effect in youth is not yet clearly demonstrated and that the population health impact of introducing e-cigarettes is still likely to be beneficial.

Considerations related to vaping as a possible gateway into cigarette smoking: an analytical review

Background: Compared to cigarette smoking, e-cigarette use is likely to present a reduced risk of smoking-related disease (SRD). However, several studies have shown that vaping predicts smoking initiation and might provide a gateway into smoking for those who otherwise would never have smoked. This paper considers various aspects of the gateway issue in youths. Methods: Here, we reviewed studies (N=15) of the gateway effect examining how extensively they accounted for confounders associated with smoking initiation in youths. We estimated how omitting a confounder, or misclassifying it, might bias the association between vaping and smoking initiation. We assessed how smoking prevalence might be affected by any true gateway effect, and examined trends in youth smoking and e-cigarette use from national surveys. Results: The list of smoking predictors adjusted for in studies reporting a significant gateway effect is not comprehensive, rarely considering internalising/externalising disorders, outcome expectancies, school performance, anxiety, parental smoking and peer attitudes. Furthermore, no study adjusted for residual confounding from inaccurately measured predictors. Better adjustment may substantially reduce the estimated gateway effect. Calculations showed that as any true gateway effects increase, there are much smaller increases in smoking prevalence, and that gateway effects increase only if initiating vaping is more frequent than initiating smoking. These effects on prevalence also depend on the relative odds of quitting vs. initiation. Data from five surveys in US/UK youths all show that, regardless of sex and age, smoking prevalence in 2014-2016 declined faster than predicted by the preceding trend, suggesting the absence of a substantial gateway effect. We also present arguments suggesting that even with some true gateway effect, introducing e-cigarettes likely reduces SRD risk. Conclusions: A true gateway effect in youths has not yet been demonstrated. Even if it were, e-cigarette introduction may well have had a beneficial population health impact.

Harm perceptions of electronic cigarettes and nicotine: A nationally representative cross-sectional survey of young people in Great Britain

BACKGROUND

E-cigarettes often contain nicotine without the most harmful constituents of tobacco smoke.

AIMS

This study aims to assess prevalence and correlates of accurately perceiving e-cigarettes as less harmful than cigarettes and that none or a small amount of the harm from smoking comes from nicotine.

METHODS

Cross-sectional survey of 2,103 11-18-year-olds in Great Britain in 2016. Prevalence of e-cigarette and nicotine harm perceptions were calculated. Logistic regressions assessed associations between accurate e-cigarette and nicotine harm perceptions and smoking, e-cigarette use, gender, age, region, social grade, family smoking, family e-cigarette use, smoking friends, public approval of smoking, and public approval of e-cigarettes. Associations between accurate e-cigarette and nicotine harm perceptions were also assessed.

RESULTS

Most (63.4%) accurate e-cigarette harm perceptions were higher among those aged 16+ (OR = 1.89 [95%CI = 1.45-2.47]), 14-15 (OR = 1.29 [1.00-1.65]), who tried/used an e-cigarette sometimes (OR = 1.51 [1.03-2.21]), with family e-cigarette use (OR = 2.11 [1.46-3.04]), who perceived public disapproval of smoking (OR = 2.11 [1.18-3.77]) and approval of e-cigarettes (OR = 2.44 [1.73-3.45]), and with accurate nicotine harm perceptions (OR = 2.05 [1.28-3.28]). Accurate nicotine harm perceptions were higher among those aged 16+ (OR = 2.60 [1.62-4.16]), from North England (OR = 1.87 [1.02-3.43]) and Wales/Scotland (OR = 2.61 [1.35-5.03]) vs. London, with family smoking (OR = 1.59 [1.05-2.42]), and with accurate e-cigarette harm perceptions (OR = 2.12 [1.32-3.41]).

CONCLUSIONS

Many young people have inaccurate harm perceptions of e-cigarettes and nicotine. Accurate e-cigarette and nicotine harm perceptions were associated with one another. E-cigarette use was associated with accurate e-cigarette but not nicotine harm perceptions; smoking was not associated with either.

Gateway effects and electronic cigarettes

BACKGROUND

E-cigarettes are alleged to be a gateway to cigarette smoking in non-smokers. This study examines whether the gateway theory has value, whether the criteria to establish causality have been met and what type of evidence is required to test this theory.

ANALYSIS

Experiments are impractical, and we may not be able to test properly the gateway effects via observational studies that simply adjust for confounders. Multivariate models cannot eliminate all the variance in propensity to smoke captured by the variable 'vaping' because of the proximity of these two behaviours. It may be difficult to prove that vaping precedes smoking when product use co-occurs and when, in fact, smoking usually precedes vaping. The gateway theory is not compatible with either (1) the decrease in smoking prevalence observed in adolescents in countries where vaping increased or (2) an increase in smoking among teenagers after age restrictions were imposed on e-cigarette purchases. A spurious gateway effect can be produced artificially by mathematical models in which a propensity to use substances is correlated with opportunities to use substances. Finally, neither nicotine medications nor smokeless tobacco produce gateway effects. Available data are compatible with a common liability model in which people who are liable to use nicotine are more likely to use both e-cigarettes and cigarettes.

CONCLUSIONS

Despite its weaknesses and scant empirical support, the gateway theory of smoking initiation has had enormous political influence. Policies based on this theory will not have the intended effects if the association between vaping and smoking is explained by common liabilities.

Perceptions and Reasons Regarding E-Cigarette Use among Users and Non-Users: A Narrative Literature Review

This paper aims to provide an in-depth understanding of the attractiveness of e-cigarettes for several different groups. For this purpose, perceptions of and reasons for e-cigarette use were systematically reviewed as reported by e-cigarette users, cigarette smokers, dual users, and non-users, among both adults and youth. MEDLINE^&reg; and Scopus were used to search for relevant articles, and references of included studies were also investigated. Two reviewers screened all titles and abstracts independently, blinded to authors and journal titles (Cohen&rsquo;s Kappa = 0.83), resulting in 72 eligible articles. Risk perceptions, perceived benefits, and reasons for e-cigarette use were categorized in themes and sub-themes. Risk perceptions included harmfulness in general, and specific health risks. Perceived benefits included improved taste and smell, and safety for bystanders. Reasons for use included (health) benefits, curiosity, smoking cessation, and friends using e-cigarettes. The findings highlight that there is a variety of perceptions and reasons mentioned by adult and youth e-cigarette users, cigarette smokers, dual users, and non-users. As such, this overview provides valuable information for scientists, public health professionals, behavior change experts, and regulators to improve future research, risk communication, and possibilities to effectively regulate e-cigarettes.

The Association Between Smoking and Electronic Cigarette Use in a Cohort of Young People

PURPOSE

Electronic cigarette (e-cigarette) use is associated with smoking initiation among young people; however, it is also possible that smoking is associated with e-cigarette initiation. This study explores these associations among young people in Great Britain.

METHODS

A longitudinal survey of 1,152 11- to 18-year-olds was conducted with baseline in April 2016 and follow-up between August and October 2016. Logistic regression models and causal mediation analyses assessed whether (1) ever e-cigarette use and escalation were associated with smoking initiation (ever smoking at follow-up) among baseline never smokers (n = 923), and (2) ever smoking and escalation were associated with e-cigarette initiation (ever e-cigarette use at follow-up) among baseline never e-cigarette users (n = 1,020).

RESULTS

At baseline, 19.8% were ever smokers and 11.4% were ever e-cigarette users. Respondents who were ever e-cigarette users (vs. never users, 53% vs. 8%, odds ratio [OR] = 11.89, 95% confidence interval [CI] = 3.56-39.72) and escalated their e-cigarette use (vs. did not, 41% vs. 8%, OR = 7.89, 95% CI = 3.06-20.38) were more likely to initiate smoking. Respondents who were ever smokers (vs. never smokers, 32% vs. 4%, OR = 3.54, 95% CI = 1.68-7.45) and escalated their smoking (vs. did not, 34% vs. 6%, OR = 5.79, 95% CI = 2.55-13.15) were more likely to initiate e-cigarette use. There was a direct effect of ever e-cigarette use on smoking initiation (OR = 1.34, 95% CI = 1.05-1.72), and ever smoking on e-cigarette initiation (OR = 1.08, 95% CI = 1.01-1.17); e-cigarette and smoking escalation, respectively, did not mediate these effects.

CONCLUSIONS

Among young people in Great Britain, ever e-cigarette use is associated with smoking initiation, and ever smoking is associated with e-cigarette initiation.

Recommended core items to assess e-cigarette use in population-based surveys

A consistent approach using standardised items to assess e-cigarette use in both youth and adult populations will aid cross-survey and cross-national comparisons of the effect of e-cigarette (and tobacco) policies and improve our understanding of the population health impact of e-cigarette use. Focusing on adult behaviour, we propose a set of e-cigarette use items, discuss their utility and potential adaptation, and highlight e-cigarette constructs that researchers should avoid without further item development. Reliable and valid items will strengthen the emerging science and inform knowledge synthesis for policy-making. Building on informal discussions at a series of international meetings of 65 experts from 15 countries, the authors provide recommendations for assessing e-cigarette use behaviour, relative perceived harm, device type, presence of nicotine, flavours and reasons for use. We recommend items assessing eight core constructs: e-cigarette ever use, frequency of use and former daily use; relative perceived harm; device type; primary flavour preference; presence of nicotine; and primary reason for use. These items should be standardised or minimally adapted for the policy context and target population. Researchers should be prepared to update items as e-cigarette device characteristics change. A minimum set of e-cigarette items is proposed to encourage consensus around items to allow for cross-survey and cross-jurisdictional comparisons of e-cigarette use behaviour. These proposed items are a starting point. We recognise room for continued improvement, and welcome input from e-cigarette users and scientific colleagues.

Favourable Perceptions of Electronic Cigarettes Relative to Cigarettes and the Associations with Susceptibility to Electronic Cigarette Use in Hong Kong Chinese Adolescents

We investigated favourable perceptions of electronic cigarettes (ECs) relative to cigarettes and their associations with EC use susceptibility in adolescents. Hong Kong Chinese Secondary 1-6 (U.S. grade 7-12) students (n = 40,202) were surveyed in 2014/2015 on EC use, cigarette smoking, favourable perceptions of ECs relative to cigarettes, EC use susceptibility, family smoking, and socio-demographic characteristics. Cox regression yielded adjusted prevalence ratios (APRs) of EC use susceptibility in never users, excluding those unaware of ECs. In all students, 8.9% were ever EC users, 47.2% reported favourable perceptions of ECs relative to cigarettes, such as less likely to cause accidents (25.2%) and less harmful to users (24.5%), and 28.9% did not know ECs. Among never EC users who were aware of ECs (n = 24,663), EC use susceptibility was associated with each of the favourable perceptions, especially greater attractiveness (APR 2.84, 95% CI 2.53-3.19), and better parental (2.75, 2.41-3.15) and school acceptability (2.56, 2.15-3.05). An increased number of favourable perceptions of ECs relative to cigarettes was associated more strongly with the susceptibility (p for trend < 0.001). Our findings inform strategies to reduce unwarranted favourable perceptions and prevent adolescent EC use.

Electronic cigarettes: an aid in smoking cessation, or a new health hazard?

The issue of electronic cigarettes is one of the most controversial topics in public health. There is intense debate and dividing opinions about their use patterns, health effects and association with smoking. This is expected since they were only recently introduced to the market and they refer to a harm-reduction approach and strategy that is not universally accepted for smoking and tobacco use in the public health community. Three main factors determine the public health impact of electronic cigarettes: (1) their safety/risk profile, both relative to smoking and in absolute terms; (2) their effectiveness for smoking reduction and cessation; (3) the patterns of use by different population subgroups, especially never-smokers, and adoption of use by youth. This analysis presents a brief overview of currently available evidence and gaps in research covering these three factors.

E-cigarette use and support for banning e-cigarette use in public places in the European Union

We investigated the factors associated with support for banning e-cigarette use in public places in the European Union (EU) and how this varies by socio-demographic determinants, use of tobacco, ever use of e-cigarettes and their perceived harm. Data are from the representative Special Eurobarometer for Tobacco survey performed in 2014 (n=27,801) in 28 EU member states. Analyses were conducted separately by tobacco use status (never, current, and former smokers) and e-cigarette experimentation status. 70.9% of never smokers, 63.1% of former smokers and 45.7% of current smokers in the EU supported a ban on the use of e-cigarettes in public places. In all groups, support for banning e-cigarettes in public places was lower among those who had experimented with e-cigarettes (adjusted odds ratios (aOR) 0.43 vs. 0.50 vs. 0.61, among never, current and former smokers respectively) and higher among those who perceived e-cigarettes as harmful (aORs 2.49 vs 2.35 vs. 2.40, among never, current and former smokers respectively). 40.5% of those who had experimented with e-cigarettes supported a ban on use in public places, although levels of support were lower among those who started using e-cigarettes in order to circumvent existing smoking bans (aOR 0.54, 95% Confidence Interval 0.45-0.64). Bans of e-cigarette use in public places in Europe have high levels of public support even among former and current tobacco smokers, although this does vary across population groups. As legislators consider approaches to e-cigarette use, public opinion is likely to become more important to the passing and enforcement of any legislation.

Electronic cigarette use and smoking initiation among youth: a longitudinal cohort study

BACKGROUND

The influence of e-cigarette use on smoking initiation is a highly controversial issue, with limited longitudinal data available for examining temporal associations. We examined e-cigarette use and its association with cigarette-smoking initiation at 1-year follow-up within a large cohort of Canadian secondary school students.

METHODS

We analyzed data from students in grades 9-12 who participated in 2 waves of COMPASS, a cohort study of purposefully sampled secondary schools in Ontario and Alberta, Canada, at baseline (2013/14) and 1-year follow-up (2014/15). We assessed cigarette smoking and e-cigarette use at baseline and follow-up using self-completed surveys. We used generalized linear mixed-effects models to examine correlates of past 30-day e-cigarette use at baseline and smoking initiation between waves within the longitudinal sample.

RESULTS

Past 30-day e-cigarette use increased from 2013/14 to 2014/15 (7.2% v. 9.7%, p < 0.001), whereas past 30-day cigarette smoking decreased slightly (11.4% v. 10.8%, p = 0.02). Among the 44 163 students evaluated at baseline, past 30-day e-cigarette use was strongly associated with smoking status and smoking susceptibility. In the longitudinal sample (n = 19 130), past 30-day use of e-cigarettes at baseline was associated with initiation of smoking a whole cigarette (adjusted odds ratio [OR] 2.12, 95% confidence interval [CI] 1.68-2.66) and with initiation of daily smoking (adjusted OR 1.79, 95% CI 1.41-2.28) at follow-up.

INTERPRETATION

E-cigarette use was strongly associated with cigarette smoking behaviour, including smoking initiation at follow-up. The causal nature of this association remains unclear, because common factors underlying the use of both e-cigarettes and conventional cigarettes may also account for the temporal order of initiation.

A critique of the US Surgeon General's conclusions regarding e-cigarette use among youth and young adults in the United States of America

BACKGROUND

In December 2016, the Surgeon General published a report that concluded e-cigarette use among youth and young adults is becoming a major public health concern in the United States of America.

METHODS

Re-analysis of key data sources on nicotine toxicity and prevalence of youth use of e-cigarettes cited in the Surgeon General report as the basis for its conclusions.

RESULTS

Multiple years of nationally representative surveys indicate the majority of e-cigarette use among US youth is either infrequent or experimental, and negligible among never-smoking youth. The majority of the very small proportion of US youth who use e-cigarettes on a regular basis, consume nicotine-free products. The sharpest declines in US youth smoking rates have occurred as e-cigarettes have become increasingly available. Most of the evidence presented in the Surgeon General's discussion of nicotine harm is not applicable to e-cigarette use, because it relies almost exclusively on exposure to nicotine in the cigarette smoke and not to nicotine present in e-cigarette aerosol emissions. Moreover, the referenced literature describes effects in adults, not youth, and in animal models that have little relevance to real-world e-cigarette use by youth. The Surgeon General's report is an excellent reference document for the adverse outcomes due to nicotine in combination with several other toxicants present in tobacco smoke, but fails to address the risks of nicotine decoupled from tobacco smoke constituents. The report exaggerates the toxicity of propylene glycol (PG) and vegetable glycerin (VG) by focusing on experimental conditions that do not reflect use in the real-world and provides little discussion of emerging evidence that e-cigarettes may significantly reduce harm to smokers who have completely switched.

CONCLUSIONS

The U.S. Surgeon General's claim that e-cigarette use among U.S. youth and young adults is an emerging public health concern does not appear to be supported by the best available evidence on the health risks of nicotine use and population survey data on prevalence of frequent e-cigarette use. Nonetheless, patterns of e-cigarettes use in youth must be constantly monitored for early detection of significant changes. The next US Surgeon General should consider the possibility that future generations of young Americans will be less likely to start smoking tobacco because of, not in spite of, the availability of e-cigarettes.

Young People's Use of E-Cigarettes across the United Kingdom: Findings from Five Surveys 2015-2017

Concern has been expressed about the use of e-cigarettes among young people. Our study reported e-cigarette and tobacco cigarette ever and regular use among 11-16 year olds across the UK. Data came from five large scale surveys with different designs and sampling strategies conducted between 2015 and 2017: The Youth Tobacco Policy Survey; the Schools Health Research Network Wales survey; two Action on Smoking and Health (ASH) Smokefree Great Britain-Youth Surveys; and the Scottish Schools Adolescent Lifestyle and Substance Use Survey. Cumulatively these surveys collected data from over 60,000 young people. For 2015/16 data for 11-16 year olds: ever smoking ranged from 11% to 20%; regular (at least weekly) smoking between 1% and 4%; ever use of e-cigarettes 7% to 18%; regular (at least weekly) use 1% to 3%; among never smokers, ever e-cigarette use ranged from 4% to 10% with regular use between 0.1% and 0.5%; among regular smokers, ever e-cigarette use ranged from 67% to 92% and regular use 7% to 38%. ASH surveys showed a rise in the prevalence of ever use of e-cigarettes from 7% (2016) to 11% (2017) but prevalence of regular use did not change remaining at 1%. In summary, surveys across the UK show a consistent pattern: most e-cigarette experimentation does not turn into regular use, and levels of regular use in young people who have never smoked remain very low.

Do electronic cigarettes increase cigarette smoking in UK adolescents? Evidence from a 12-month prospective study

BACKGROUND

In cross-sectional surveys, increasing numbers of adolescents report using both electronic cigarettes (e-cigarettes) and cigarettes. This study assessed whether adolescent e-cigarette use was associated prospectively with initiation or escalation of cigarette use.

METHODS

Data were from 2836 adolescents (aged 13-14 years at baseline) in 20 schools in England. At baseline, breath carbon monoxide levels, self-reported e-cigarette and cigarette use, sex, age, friends and family smoking, beliefs about cigarette use and percentage receiving free school meals (measure of socioeconomic status) were assessed. At 12-month follow-up, self-reported cigarette use was assessed and validated by breath carbon monoxide levels.

RESULTS

At baseline, 34.2% of adolescents reported ever using e-cigarettes (16.0% used only e-cigarettes). Baseline ever use of e-cigarettes was strongly associated with subsequent initiation (n=1726; OR 5.38, 95% CI 4.02 to 7.22; controlling for covariates, OR 4.06, 95% CI 2.94 to 5.60) and escalation (n=318; OR 1.91, 95% CI 1.14 to 3.21; controlling for covariates, this effect became non-significant, OR 1.39, 95% CI 0.97 to 1.82) of cigarette use.

CONCLUSIONS

This is the first study to report prospective relationships between ever use of e-cigarettes and initiation and escalation of cigarette use among UK adolescents. Ever use of e-cigarettes was robustly associated with initiation but more modestly related to escalation of cigarette use. Further research with longer follow-up in a broader age range of adolescents is required.

Prevalence and correlates of electronic cigarette use among Canadian students: cross-sectional findings from the 2014/15 Canadian Student Tobacco, Alcohol and Drugs Survey

BACKGROUND

Over the past decade, youth tobacco use has declined, and electronic cigarettes (e-cigarettes) have entered the market. The aims of this study were to describe the prevalence of e-cigarette use among youth in Canada, by province, across sociodemographic variables and smoking-related correlates; and to examine associations among e-cigarette use, sociodemographic variables and smoking-related correlates, with adjustment for other factors.

METHODS

The 2014/15 Canadian Student Tobacco, Alcohol and Drugs Survey, a biennial, school-based survey, was administered to students in grades 6-12 in all Canadian provinces. Logistic regression models were fitted to estimate odds of ever and past 30-day e-cigarette use by sociodemographic variables and smoking-related correlates.

RESULTS

A total of 336 schools from 128 school boards (47% of eligible schools approached) and 42 094 students (66% of eligible students approached) participated in the survey. In Canada, 17.7% (95% confidence interval [CI] 16.4%-18.9%) of students in grades 6-12 reported ever using e-cigarettes, and 5.7% (95% CI 5.2%-6.3%) reported past 30-day use. Substantial variation was observed across provinces. Female students had decreased odds of past 30-day use relative to male students (odds ratio [OR] 0.71, 95% CI 0.59-0.86), whereas current smokers (OR 10.0, 95% CI 6.66-15.02) and experimental smokers (OR 3.61, 95% CI 2.40-5.42) had increased odds relative to never smokers. Students who perceived that access was easy also had increased odds of using e-cigarettes relative to students who perceived that access was difficult (OR 3.86, 95% CI 2.96-5.03). Students who believed that regular use entailed slight risk (OR 0.68, 95% CI 0.52-0.88) and those who did not know risk levels (OR 0.31, 95% CI 0.21-0.46) had decreased odds compared with those perceiving no risk.

INTERPRETATION

Our data confirm that many youth used e-cigarettes in the 30 days preceding the survey, although rates were substantially higher among current and experimental smokers than among students who had never tried smoking.

Factors associated with electronic cigarette use among current cigarette-smoking adolescents in the Republic of Korea

OBJECTIVE

Despite a rapid increase in electronic cigarette (e-cigarette) use and substantial dual use of cigarettes and e-cigarettes among adolescents, little is currently known about adolescent e-cigarette use. Thus, this study aimed to investigate (a) rates of e-cigarette use and (b) significant factors associated with e-cigarette use among current cigarette users in adolescence.

METHODS

We analyzed secondary data collected from a nationally representative sample of Korean adolescents. Our study sample included 6307 current smokers. Our dependent variable was e-cigarette use and consisted of three categories (nonuse, former use, and current use); independent variables included demographics, perceived stress, parental and friends' smoking, three characteristics of cigarette smoking, and other health risk behaviors. Descriptive statistics was used for the first aim; multinomial logistic regression analysis was performed for the second aim.

RESULTS

Of current cigarette users, 20% smoked e-cigarettes in their lifetime but not within the past 30days (former users), and 42% smoked e-cigarettes in their lifetime and within the past 30days (current users). Both former and current e-cigarette use were significantly associated with male gender, higher grades, higher weekly allowance, residence in urban areas, friends' smoking, daily smoking, a higher number of cigarettes smoked, and quit attempts. In addition, current e-cigarette use was significantly associated with at-risk drinking, lifetime drug use, and lifetime sexual intercourse.

CONCLUSIONS

E-cigarette use should be included in intervention strategies for smoking prevention and cessation. Strict regulations should be implemented in order to prohibit easy access to e-cigarettes and forbid advertising of e-cigarettes as well.

Practice Patterns and Perceptions of Chest Health Care Providers on Electronic Cigarette Use: An In-Depth Discussion and Report of Survey Results

Introduction

The emergence of electronic cigarettes (ECs) has become a growing phenomenon that has sharply split opinion among the public health community, physicians, and lawmakers.

Aims

We sought to determine chest physician perceptions regarding ECs.

Methods

We conducted a web-based survey of 18,000 American College of Chest Physician (CHEST) members to determine healthcare provider experiences with EC users and to characterize provider perceptions regarding ECs.

Results/Findings

There were 994 respondents. 88% reported that patients had asked their opinion of ECs, and 31% reported EC use among at least 10% of their patients. More disagreed than agreed (41% vs. 21%) that patients could improve their health by switching from tobacco smoking to daily EC use. Respondents were split on whether ECs promote tobacco cessation (32% agree vs. 33% disagree).

Conclusions

Current perceptions of ECs are variable among providers. More than 1/3 of respondents felt that EC's could be used for smoking cessation for smokers who failed prior quit attempts with approved therapies. However, many respondents were not convinced that ECs will reduce harms from tobacco use. There is an urgent need to generate additional high quality scientific data regarding ECs to inform chest physicians, health professionals and the general public.

The Influence of a Mouthpiece-Based Topography Measurement Device on Electronic Cigarette User's Plasma Nicotine Concentration, Heart Rate, and Subjective Effects Under Directed and Ad Libitum Use Conditions

INTRODUCTION

Electronic cigarettes e-cigarettes aerosolize a liquid solution often containing nicotine. e-cigarette nicotine delivery may be influenced by user puffing behaviors ("puff topography"). E-cigarette puff topography can be recorded using mouthpiece-based computerized systems. The present study sought to examine the extent to which these systems influence e-cigarette nicotine delivery and other e-cigarette associated acute effects under ad libitum use conditions.

METHODS

Plasma nicotine concentration, heart rate, and subjective effects were assessed in 29 experienced e-cigarette users using their preferred e-cigarette battery and liquid (≥12mg/mL nicotine) in two sessions differing only by the presence of a mouthpiece-based device. In both sessions, participants completed a directed e-cigarette use bout (10 puffs, 30-s interpuff interval) and a 90-min ad libitum bout. Puff topography was recorded in the session with the topography mouthpiece.

RESULTS

Plasma nicotine, heart rate, and subjective effects, aside from "Did the e-cigarette Taste Good?" were independent of topography measurement (higher mean taste ratings were observed in the no topography condition). Mean (SEM) plasma nicotine concentration following the ad libitum bout was 34.3ng/mL (4.9) in the no topography condition and 35.7ng/mL (4.3) in the topography condition. Longer puff durations, longer interpuff intervals, and larger puff volumes were observed in the ad libitum relative to the directed bout.

CONCLUSIONS

E-cigarette use significantly increased plasma nicotine concentration and heart rate while suppressing abstinence symptoms. These effects did not differ when a topography mouthpiece was present. Future studies using ad libitum e-cigarette use bouts would facilitate understanding of e-cigarette toxicant yield.

IMPLICATIONS

No prior study has examined whether mouthpiece-based topography recording devices influence e-cigarette associated nicotine delivery, heart rate, or subjective effects under ad libitum conditions or assessed ad libitum puff topography in experienced individuals using their preferred e-cigarette battery and liquid with a mouthpiece-based computerized device. E-cigarette use significantly increased plasma nicotine concentration and heart rate while suppressing abstinence symptoms. These effects did not differ when a topography mouthpiece was present. Ad libitum puff topography differed from puff topography recorded during directed puffing. These findings suggest that future studies using ad libitum use bouts would facilitate better understanding of e-cigarette toxicant yield.

Overview of Electronic Nicotine Delivery Systems: A Systematic Review

CONTEXT

Rapid developments in e-cigarettes, or electronic nicotine delivery systems (ENDS), and the evolution of the overall tobacco product marketplace warrant frequent evaluation of the published literature. The purpose of this article is to report updated findings from a comprehensive review of the published scientific literature on ENDS.

EVIDENCE ACQUISITION

The authors conducted a systematic review of published empirical research literature on ENDS through May 31, 2016, using a detailed search strategy in the PubMed electronic database, expert review, and additional targeted searches. Included studies presented empirical findings and were coded to at least one of nine topics: (1) Product Features; (2) Health Effects; (3) Consumer Perceptions; (4) Patterns of Use; (5) Potential to Induce Dependence; (6) Smoking Cessation; (7) Marketing and Communication; (8) Sales; and (9) Policies; reviews and commentaries were excluded. Data from included studies were extracted by multiple coders (October 2015 to August 2016) into a standardized form and synthesized qualitatively by topic.

EVIDENCE SYNTHESIS

There were 687 articles included in this systematic review. The majority of studies assessed patterns of ENDS use and consumer perceptions of ENDS, followed by studies examining health effects of vaping and product features.

CONCLUSIONS

Studies indicate that ENDS are increasing in use, particularly among current smokers, pose substantially less harm to smokers than cigarettes, are being used to reduce/quit smoking, and are widely available. More longitudinal studies and controlled trials are needed to evaluate the impact of ENDS on population-level tobacco use and determine the health effects of longer-term vaping.