Effects of e-cigarette use on cigarette smoking among U.S. youth, 2004-2018

Cigarette smoking decline among US young adults from 2000 to 2019, in relation to state-level cigarette price and tobacco control expenditure

OBJECTIVE

To investigate the association of state-level cigarette price and tobacco control expenditure with the large 2000-2019 decline in cigarette smoking among US 18-24 year-olds.

METHODS

Smoking behaviour was assessed in the 24 most populous US states using the 1992-2019 Tobacco Use Supplements to the Current Population Survey; association with price and expenditure was tested using adjusted logistic regression. States were ranked by inflation-adjusted average price and tobacco control expenditure and grouped into tertiles. State-specific time trends were estimated, with slope changes in 2001/2002 and 2010/2011.

RESULTS

Between 2000 and 2010, the odds of smoking among US young adults decreased by a third (adjusted OR, AOR 0.68, 95% CI 0.56 to 0.84). By 2019, these odds were one-quarter of their 2000 level (AOR 0.24, 95% CI 0.19 to 0.31). Among states in the lowest tertile of price/expenditure tobacco control activity, initially higher young adult smoking decreased by 13 percentage points from 2010 to 2018-2019, to a prevalence of 5.6% (95% CI 4.5% to 6.8%), equal to that in the highest tobacco-control tertile of states (6.5%, 95% CI 5.2% to 7.8%). Neither state tobacco control spending (AOR 1.0, 95% CI 0.999 to 1.002) nor cigarette price (AOR 0.96, 95% CI: 0.92 to 1.01) were associated with young adult smoking in statistical models. In 2019, seven states had prevalence over 3 SDs higher than the 24-state mean.

CONCLUSION

National programmes may have filled a gap in state-level interventions, helping drive down the social acceptability of cigarette smoking among young adults across all states. Additional interventions are needed to assist high-prevalence states to further reduce smoking.

Longitudinal bidirectional association between youth electronic cigarette use and tobacco cigarette smoking initiation in Thailand

INTRODUCTION

This study quantifies the longitudinal association between e-cigarette use and subsequent conventional cigarette initiation and vice versa among Thai youths.

METHODS

Data from a longitudinal survey of 6045 Thai seventh grade students with baseline in 2019 and the 12-month follow-up in 2020 were analysed using complex survey multivariate logistic regressions to assess whether e-cigarette use was associated with subsequent cigarette smoking (ever, current and dual product users at follow-up) among baseline never smokers.

RESULTS

Consistent with prior findings from other countries, among those who had never smoked cigarettes at baseline, ever e-cigarette users were more likely to try cigarette smoking (adjusted OR 4.44; 95% CI 2.23 to 8.86; p<0.001), or become dual users (adjusted OR 5.31; 95% CI 2.63 to 10.74; p<0.001) 1 year later. Baseline current e-cigarette users were more likely to become ever smokers (adjusted OR 5.37; 95% CI 1.82 to 15.90; p=0.005), current smokers (OR 3.92; 95% CI 1.69 to 9.14; p=0.003) and dual product users (adjusted OR 6.96; 95% CI 1.54 to 31.38; p=0.015) at the 12-month follow-up than non-e-cigarette users. Similarly, among never e-cigarette users at baseline, ever cigarette smoking were more likely to try e-cigarettes (adjusted OR 3.38; 95% CI 1.66 to 6.88; p=0.002), currently use e-cigarettes (adjusted OR 2.75; 95% CI 1.47 to 5.13; p=0.003) and currently use both e-cigarettes and cigarettes (adjusted OR 4.87; 95% CI 2.92 to 8.13; p<0.001) at the follow-up than never smokers. Among never e-cigarette users at baseline, current-cigarette smoking were more likely to try e-cigarettes (adjusted OR 6.21; 95% CI 2.58 to 14.95; p<0.001), currently use e-cigarettes (adjusted OR 2.80; 95% CI 1.27 to 6.14; p=0.014) and currently use both e-cigarettes and cigarettes (adjusted OR 7.70; 95% CI 3.45 to 17.19; p<0.001) at the follow-up than never smokers.

CONCLUSIONS

This longitudinal study in Asian low-income and middle-income countries supports the prospective association of youth e-cigarette use with subsequent smoking initiation and youth cigarette use with subsequent e-cigarette initiation that is similar to that observed in high-income Western countries.

Vuse Solo e-cigarettes do not provide net benefits to public health: a scientific analysis of FDA's marketing authorisation

In October 2021, the US Food and Drug Administration (FDA) authorised marketing of RJ Reynolds Vapor Company's (RJR) Vuse Solo e-cigarette through FDA's Premarket Tobacco Product Application (PMTA) pathway. FDA concluded that RJR demonstrated Vuse products met the statutory standard of providing a net benefit to public health. A review of FDA's scientific justification reveals deficiencies: (1) not adequately considering Vuse's popularity with youth and evidence that e-cigarettes expanded the nicotine market and stimulate cigarette smoking; (2) trading youth addiction for unproven adult benefit without quantifying these risks and benefits; (3) not considering design factors that appeal to youth; (4) not addressing evidence that e-cigarettes used as consumer products do not help smokers quit and promote relapse in former smokers; (5) not discussing evidence that dual use is more dangerous than smoking; (6) narrowly focusing on the fact that e-cigarettes deliver lower levels of some toxicants without addressing direct evidence on adverse health effects; (7) downplaying significant evidence of other substantial harms; (8) not acting on FDA's own study showing no all-cause mortality benefit of reducing (but not stopping) cigarette use; and (9) improperly considering e-cigarettes' high abuse liability and potential for high youth addiction and undermining tobacco cessation. Because marketing these products is not appropriate for the protection of the public health, FDA should reconsider its Vuse marketing order as statutorily required and not use it as a template for other e-cigarette PMTAs. Policymakers outside the USA should anticipate that tobacco companies will use FDA's decision to try to weaken tobacco control regulation of e-cigarettes and promote their products.

Analysis of FDA's Vuse market authorisation: limitations and opportunities

This special communication provides a physicians' critique of the US Food and Drug Administration (FDA)'s decision to authorise the Vuse Solo (Vuse) Premarket Tobacco Application (PMTA). The PMTA authorisation represents the first time that FDA has authorised an Electronic Nicotine Delivery System (ENDS) for marketing in the USA. Using the FDA Decision Summary, the special communication identifies significant unanswered public health and scientific questions that prevent the authors from reaching FDA's conclusion that Vuse meets the Appropriate for the Protection of the Public Health (APPH) standard. The authors recommend FDA suspend the market authorisation and use these questions to re-evaluate the PMTA, and to prospectively monitor whether Vuse meets APPH standard. The special communication advances the ENDS harm reduction conversation because it calls for national tobacco regulators to develop an epidemiological prediction of ENDS impact on the population and to expand the scope of their analysis to evaluate the impacts of ENDS on congenital birth defects, abuse liability and non-flavour drivers of youth usage. Through learning from the American experience regulating Vuse, national tobacco regulators around the globe will be better equipped to evaluate the impact of ENDS on the public health.

Changes in smoking patterns and characteristics of Koreans using the Korea National Health and Nutrition Examination Survey 2013-2021 data

OBJECTIVES

This study explored factors related to Korean adults' smoking patterns and also the reasons for using new types of tobacco products.

STUDY DESIGN

Cross-sectional survey.

METHODS

Data from the Korea National Health and Nutrition Examination Survey from 2013 to 2021 were used. The prevalence of the use of electronic cigarettes (e-cigarettes) or heated tobacco products (HTPs) alone or in combination with conventional cigarettes (CC) and the reasons for using new tobacco products are presented. Factors associated with using new types of tobacco products alone or in combination with CC compared to exclusive CC users were identified using multinomial logistic regression analysis.

RESULTS

The prevalence of current smoking was 25.54% in 2013 and 23.05% in 2021, with no significant change. The prevalence of CC decreased from 23.39% in 2013 to 15.77% in 2021. The prevalence of new tobacco use in combination with CC did not show a definite trend. The prevalence of exclusive use of new tobacco was <1% until 2018 and has rapidly increased thereafter. Of the HTPs users, 46.68% responded with 'no cigarette smell' as the main reason for HTPs use, followed by 'It seems less harmful than cigarette' (19.19%), and 'It seems to be helpful for quitting smoking' (15.04%). Of the e-cigarette users, 45.19% responded 'It seems to be helpful for quitting smoking' as the main reason for e-cigarette use, followed by 'It is less harmful than cigarettes' (19.98%). Compared to CC users, new tobacco users were younger, had a higher household income or education, and used more nutritional supplements.

CONCLUSION

Regulations for newer tobacco products are more lenient than for traditional cigarettes, leading to misunderstandings, especially among women and young people. To increase awareness of the risks of these products, specific policies such as disclosure of ingredients, ban on online sales, and increase in consumption tax, are needed.

Household vaping bans and youth e-cigarette use

AIMS

The aims of this study were to measure whether household bans on vaping were associated with lower odds of youth past-month vaping when compared with (1) otherwise similar youth whose households did not have a vaping ban (using coarsened exact matching); and (2) themselves in waves when their household did not have a ban (using hybrid panel models). We used the same analytical strategies to examine cross-sectional associations between household smoking bans and adolescents' past-month cigarette smoking.

DESIGN

This was a longitudinal study using data from a nationally representative sample of youth (age 12-17 years) in the Population Assessment of Tobacco and Health Study.

SETTING

United States of America.

PARTICIPANTS

A total of 16 214 adolescents followed over 48 103 total observations (approximately three waves).

MEASUREMENTS

Measurements comprised youth past-month e-cigarette and cigarette use and parent-reported household bans on vaping and smoking. Potential confounders were prior adolescent smoking, vaping, and other nicotine product use; parent current smoking, vaping, and other nicotine use; adolescent peer e-cigarette/cigarette use; parental monitoring; and demographic characteristics.

FINDINGS

Before matching, smoking bans were associated with 46% lower odds of youth smoking [odds ratio (OR) = 0.54; 95% confidence interval (CI) = 0.41-0.70] and vaping bans with 37% lower odds of youth e-cigarette use (OR = 0.63; 95% CI = 0.50-0.80). However, households with and without bans differed significantly on all confounders before matching. After matching, household vaping bans were associated with 56% lower odds of youth vaping (OR = 0.44; 95% CI = 0.33-0.58). Results from hybrid panel models also revealed 37% lower odds of vaping in waves when youth lived in a vape-free household compared to waves when they did not (OR = 0.63; 95% CI = 0.50-0.78). Associations between smoking bans and youth smoking were not statistically significant after matching or when using hybrid panel models.

CONCLUSIONS

Household vaping bans appear to be associated with lower odds of past-month vaping among US adolescents, compared with similar youth whose households did not have a ban and to themselves in waves when their households did not have a ban.

Shift From Smoking Cigarettes to Vaping Nicotine in Young Adults

This survey study assesses trends in nicotine use among young adults in the US between 2013 and 2021.

Dramatic Reductions in Cigarette Smoking Prevalence among High School Youth from 1991 to 2022 Unlikely to Have Been Undermined by E-Cigarettes

There is concern that youth e-cigarette use could lead youth to initiate cigarette smoking. This study identifies epochs of cigarette smoking among U.S. high school students in three commonly utilized national school-based surveys over three decades without a priori assumptions. We examined trends in ever and current cigarette smoking among high school youth from 1991 to 2022 in three datasets: Monitoring the Future (MTF), the National Youth Risk Behavior Survey (NYRBS) and the National Youth Tobacco Survey (NYTS) via Joinpoint regression. High stable rates of ever smoking were noted from 1991 to 1999 (NYRBS and MTF) and then significantly declined from 1999 to 2013; declines accelerated through to 2022. In the NYTS, ever cigarette smoking significantly declined from 1999 to 2018 and then declines accelerated to 2022. Current cigarette smoking reached its peak in 1997, and then significantly declined from 1997 to 2013 in the NYRBS and MTF and similarly in the NYTS from 1999 to 2018. Declines in current smoking then accelerated in all surveys through to 2022. These findings suggest dramatic successes in reducing youth smoking since the late 1990s, with more rapid declines in prevalence in the past decade.

Effects of reduced-risk nicotine-delivery products on smoking prevalence and cigarette sales: an observational study

Background

It is not currently clear what impact alternative nicotine-delivery products (electronic cigarettes, heated tobacco products and snus) have on smoking rates and cigarette sales.

Objective

To assess whether access to these products promotes smoking in the population.

Design and data sources

We examined associations of alternative nicotine product use and sales with smoking rates and cigarette sales overall, and in different age and socioeconomic groups, and compared smoking prevalence over time in countries with contrasting regulations of these products. For electronic cigarettes, we examined data from countries with historically similar smoking trajectories but differing current electronic cigarette regulations (United Kingdom and United States of America vs. Australia, where sales of nicotine-containing electronic cigarettes are banned); for heated tobacco, we used data from countries with state tobacco monopolies, where cigarette and heated tobacco sales data are available (Japan, South Korea), and for snus we used data from Sweden.

Analysis methods

We pre-specified dynamic time series analyses to explore associations between use and sales of alternative nicotine-delivery products and smoking prevalence and cigarette sales, and time series analyses to compare trends of smoking prevalence in countries with different nicotine product policies.

Results

Because of data and analysis limitations (see below), results are only tentative and need to be interpreted with caution. Only a few findings reached statistical significance and for most results the Bayes factor indicated inconclusive evidence. We did not find an association between rates of smoking and rates of the use of alternative nicotine products. The increase in heated tobacco product sales in Japan was accompanied by a decrease in cigarette sales. The decline in smoking prevalence seems to have been slower in Australia than in the United Kingdom overall, and slower than in both the United Kingdom and the United States of America among young people and also in lower socioeconomic groups. The decline in cigarette sales has also accelerated faster in the United Kingdom than in Australia.

Limitations

Most of the available data had insufficient data points for robust time series analyses. The assumption of our statistical approach that causal interactions are more likely to be detected when longer-term changes are screened out may not apply for short time series and in product interaction scenarios, where short-term fluctuations can be caused by, for example, fluctuations in prosperity or product supplies. In addition, due to dual use, prevalence figures for smoking and alternative product use overlap. The ecological study design limits the causal inferences that can be made. Longer time periods are needed for any effects of exclusive use of the new products on smoking prevalence to emerge.

Conclusions

We detected some indications that alternative nicotine products are competing with cigarettes rather than promoting smoking and that regulations that allow their sales are associated with a reduction rather than an increase of smoking, but the findings are inconclusive because of insufficient data points and issues with the assumptions of the pre-specified statistical analyses.

Future work

As further prevalence and sales data emerge the analyses will become more informative. Accessing sales figures in particular is the current research priority.

Study registration

The project is registered on Open Science Framework https://osf.io/bd3ah.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (NIHR129968) and will be published in full in Public Health Research; Vol. 11, No. 7. See the NIHR Journals Library website for further project information.

Sexual Identity Differences in Tobacco (Re)Uptake: Testing Mediation by Internalizing and Externalizing Symptoms

INTRODUCTION

Tobacco use among gay, lesbian, and bisexual individuals is disproportionately higher than among heterosexual individuals. Identifying the mechanisms behind these differences can inform prevention and cessation efforts aimed at advancing health equity. Internalizing and externalizing symptoms as mediators of tobacco (re)uptake among sexual minority individuals was examined.

METHODS

Waves 4 and 5 of the Population Assessment of Tobacco and Health (2016-2019) study were analyzed in 2022. Adolescents aged ≥14 and adults years not using tobacco at Wave 4 (n=21,676) were included. Wave 4 sexual identity was categorized as heterosexual, gay/lesbian, bisexual, or something else. Associations of sexual identity with (re)uptake of cigarette use, E-cigarette use, and polytobacco use at Wave 5 were assessed, along with possible mediation of these associations by Wave 4‒internalizing and ‒externalizing symptoms.

RESULTS

Internalizing and externalizing symptoms predicted tobacco (re)uptake regardless of sexual identity, particularly for female individuals. Gay/lesbian females (AOR=2.26; 95% CI=1.14, 4.48) and bisexual females (AOR=1.36; 95% CI=1.06, 1.74) had greater odds of E-cigarette (re)uptake than heterosexual females. High internalizing and externalizing symptoms accounted for over one third of the difference in E-cigarette (re)uptake among bisexual compared with that among heterosexual females. Males who reported sexual identity as something-else had lower odds of cigarette (re)uptake than heterosexual males (AOR=0.19; 95% CI=0.06, 0.66); this association was not mediated by internalizing and externalizing symptoms.

CONCLUSIONS

Internalizing and externalizing symptoms uniquely contribute to E-cigarette (re)uptake among bisexual females. Strategies that reduce sexual minority stressors and resulting psychological distress may help to reduce tobacco use disparities.

Impacts of EU Tobacco Products Directive regulations on use of e-cigarettes in adolescents in Great Britain: a natural experiment evaluation

Background

E-cigarettes are a popular smoking-cessation tool. Although less harmful than tobacco, use of e-cigarettes by non-smokers should be prevented. There is concern about the use of e-cigarettes by young people and that e-cigarettes may renormalise smoking. In May 2016, Tobacco Products Directive regulations aimed to reduce e-cigarettes' appeal to young people.

Aims

To examine the effects of the Tobacco Products Directive regulations on young people's use of e-cigarettes, and the role of e-cigarettes in renormalising smoking.

Design

A mixed-method natural experimental evaluation combining secondary analyses of survey data, with process evaluation, including interviews with young people, policy stakeholders, retailers and trading standards observers, and observations of retail settings.

Settings

Wales, Scotland and England.

Participants

Survey participants were aged 13-15 years, living in England, Scotland or Wales and participated in routinely conducted surveys from 1998 to 2019. Process evaluation participants included 14- to 15-year-olds in England, Scotland and Wales, policy stakeholders, trading standards offices and retailers.

Intervention

Regulation of e-cigarettes, including bans on cross-border advertising, health warnings and restrictions on product strength.

Comparison group

Interrupted time series design, with baseline trends as the comparator.

Main outcome measures

The primary outcome was ever e-cigarette use. Secondary outcomes included regular use, ever and regular smoking, smoking attitudes, alcohol and cannabis use.

Data capture and analysis

Our primary statistical analysis used data from Wales, including 91,687 young people from the 2013-19 Health Behaviour in School-aged Children and School Health Research Network surveys. In Scotland, we used the Scottish Schools Adolescent Lifestyle and Substance Use Survey and in England we used the Smoking Drinking and Drug Use surveys. The process evaluation included interviews with 73 young people in 2017 and 148 young people in 2018, 12 policy stakeholders, 13 trading standards officers and 27 retailers. We observed 30 retail premises before and after implementation. Data were integrated using the Medical Research Council's process evaluation framework.

Results

Ever smoking continued to decline alongside the emergence of e-cigarettes, with a slight slowing in decline for regular use. Tobacco Products Directive regulations were described by stakeholders as well implemented, and observations indicated good compliance. Young people described e-cigarettes as a fad and indicated limited interaction with the components of the Tobacco Products Directive regulations. In primary statistical analyses in Wales [i.e. short (to 2017) and long term (to 2019)], growth in ever use of e-cigarettes prior to Tobacco Products Directive regulations did not continue after implementation. Change in trend was significant in long-term analysis, although of similar magnitude at both time points (odds ratio 0.96). Data from England and Scotland exhibited a similar pattern. Smoking followed the opposite pattern, declining prior to the Tobacco Products Directive regulations, but plateauing as growth in e-cigarette use stalled.

Limitations

Alternative causal explanations for changes cannot be ruled out because of the observational design.

Conclusions

Young people's ever and regular use of e-cigarettes appears to have peaked around the time of the Tobacco Products Directive regulations and may be declining. Although caution is needed in causal attributions, findings are consistent with an effect of regulations. Our analysis provides little evidence that e-cigarettes renormalise smoking. More recent data indicate that declines in smoking are plateauing.

Future work

International comparative work to understand differences in use of e-cigarettes, and tobacco, within varying regulatory frameworks is a priority.

Study registration

This study is registered as ResearchRegistry4336.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 11, No. 5. See the NIHR Journals Library website for further project information.

Psychoactive Comfort Products or Snacks: How Chinese Young Adults Perceive the Potentially Addictive Nature of E-Cigarettes

The potential health value and pitfalls of e-cigarettes are currently under dispute in the scientific community. Exploring young adult e-cigarette users' perceptions would assist in adding a public dimension of understanding to the literature and in scientific public health decision making. Therefore, in this study, we collected and analyzed data from interviews with young adult (n = 14) e-cigarette users and found that many referred to e-cigarettes as "snacks," indicating that they considered that both their frequency of use and addiction were manageable and that they could stop using e-cigarettes at any time. To further understand the behavior of Chinese young adults in relation to their perception of e-cigarettes as a "snack", the study developed a social context framework (crossroads model) and psychological judgment model to explain how youth e-cigarette users' perception of "controlled addiction and ready cessation" arises. These models can be used to assess the effectiveness of e-cigarette policy.

Re: Impact of the "e-cigarette era" on cigarette smoking among youth: A population-level study

Our original paper is: Harrell MB, Mantey DS, Baojiang C, Kelder SH, Barrington-Trimis J. Impact of the e-cigarette era on cigarette smoking among youth in the United States A population-level study. Preventive Medicine 2022; 164:107265). This is a response to correspondence received from Foxon and Juul Labs Inc. (JUUL) regarding our original paper.

Adolescents' own views on their risk behaviors, and the potential effects of being labeled as risk-takers: A commentary and review

Adolescents are stereotypically viewed as risk-takers ("stereotypical risk-takers") in science, mainstream media, fictional literature and in everyday life. However, increasing research suggests that adolescents do not always engage in "heightened" risk-taking, and adolescents' own perspectives (motives) on risk-taking are largely neglected in research. Hence, this paper is a commentary and review with two aims. First, taking a cross-national perspective, we discuss the definition of adolescence and risk behavior. We argue that much of the research on what drives adolescent risk behavior (e.g., substance use) focuses on the harms that this behavior promotes rather than on the need to explore and grow into adulthood. Thereafter we summarize the dominant approach to studying motives behind substance use, which has mostly considered young adults, and which has typically not focused on adolescents' own self-generated motives. The few empirical studies (including one of our qualitative studies) on adolescents' own motivations for engaging in risk behavior (i.e., cannabis use, alcohol use, and tobacco smoking) show that the most frequently mentioned motives by adolescents were being cool/tough, enjoyment, belonging, having fun and experimenting and coping. Interestingly, the "cool/tough identity" motive is virtually overlooked in research on adolescent risk-taking. The above-mentioned motives, however, generally support newer theories, such as the Developmental Neuro-Ecological Risk-taking Model (DNERM) and the Life-span Wisdom Model that suggest that adolescents' motivations to engage in risk-taking include experimentation, identity development, explorative behavior, and sensation seeking, all of which run counter to the stereotype of adolescents engaging in risk-taking due to "storm and stress." Hence, we also briefly consider additional recent attempts to study positive forms of risk taking. Second, extrapolating from sociological/criminological theories on labeling, we suggest that caution is warranted when (inaccurately) labeling adolescents as the "stereotypical risk-takers," because this can instigate a risk-taking identity in adolescents and/or motivate them to associate with risk-taking peers, which could in turn lead to maladaptive forms of risk-taking. Empirical research testing these hypotheses is needed. To conclude we argue that research on adolescent risk-taking could further benefit from considering adolescent's own motivations, which is also in line with the participatory approach advocated by international children's rights standards.

Impact of the e-cigarette era on cigarette smoking among youth in the United States: A population-level study

To examine and compare trends in past 30-day cigarette smoking among adolescents in the US from 2002 to 2019, before and after the onset of the "e-cigarette era" in 2014. Using National Youth Tobacco Survey (NYTS) data from 2002 to 2019, we modeled the prevalence of past 30-day cigarette smoking over time. A total of n = 274,551 (weighted N = 340,403,754) middle and high school students were included in this study. Interrupted time series analyses were used to examine changes in cigarette smoking over time and compare trends in cigarette smoking pre- and post-2014. Models were applied to the full sample and stratified by middle (6th-8th grade) and high school (9th-12th grade). The observed number of current adolescent cigarette smokers post-2014 was compared to the predicted number, given trends in cigarette smoking prevalence observed pre-2014. Among all students, past 30-day cigarette smoking declined by approximately 0.75% per year from 2002 to 2013 (p < 0.001). Following a significant drop in prevalence from 2013 to 2014 (1.64%; p < 0.001), the decline in past 30-day cigarette smoking slowed significantly to approximately 0.37% per year (p < 0.001), from 2015 to 2019. We estimate that the onset of the "e-cigarette era" in 2014 corresponded to over 1.66 million (95% CI: 1.57 m - 1.75 m) more past 30-day cigarette smokers from 2015 to 2019, cumulatively. The rate of decline in past 30-day cigarette smoking prevalence among adolescents observed since 2002 slowed with the onset of the "e-cigarette era" in 2014, providing evidence at a population-level for the "gateway effect."

Nicotine Addiction and Intensity of e-Cigarette Use by Adolescents in the US, 2014 to 2021

IMPORTANCE

As e-cigarettes have become more effective at delivering the addictive drug nicotine, they have become the dominant form of tobacco use by US adolescents.

OBJECTIVE

To measure intensity of use of e-cigarettes, cigarettes, and other tobacco products among US adolescents and their dependence level over time.

DESIGN, SETTING, AND PARTICIPANTS

This survey study analyzed the cross-sectional National Youth Tobacco Surveys from 2014 to 2021. Confirmatory analysis was conducted using Youth Behavioral Risk Factor Surveillance System from 2015 to 2019. The surveys were administered to national probability samples of US students in grades 6 to 12.

EXPOSURES

Use of e-cigarettes and other tobacco products before and after the introduction of e-cigarettes delivering high levels of nicotine.

MAIN OUTCOMES AND MEASURES

First tobacco product used, age at initiation of use, intensity of use (days per month), and nicotine addiction (measured as time after waking to first use of any tobacco product).

RESULTS

A total of 151 573 respondents were included in the analysis (51.1% male and 48.9% female; mean [SEM] age, 14.57 [0.03] years). Prevalence of e-cigarette use peaked in 2019 and then declined. Between 2014 and 2021, the age at initiation of e-cigarette use decreased, and intensity of use and addiction increased. By 2017, e-cigarettes became the most common first product used (77.0%). Age at initiation of use did not change for cigarettes or other tobacco products, and changes in intensity of use were minimal. By 2019, more e-cigarette users were using their first tobacco product within 5 minutes of waking than for cigarettes and all other products combined. Median e-cigarette use also increased from 3 to 5 d/mo in 2014 to 2018 to 6 to 9 d/mo in 2019 to 2020 and 10 to 19 d/mo in 2021.

CONCLUSIONS AND RELEVANCE

The changes detected in this survey study may reflect the higher levels of nicotine delivery and addiction liability of modern e-cigarettes that use protonated nicotine to make nicotine easier to inhale. The increasing intensity of use of modern e-cigarettes highlights the clinical need to address youth addiction to these new high-nicotine products over the course of many clinical encounters. In addition, stronger regulation, including comprehensive bans on the sale of flavored tobacco products, should be implemented.

Trends in Alcohol, Cigarette, E-Cigarette, and Nonprescribed Pain Reliever Use Among Young Adults in Washington State After Legalization of Nonmedical Cannabis

PURPOSE

Liberalization of cannabis laws may be accompanied by changes in the use of substances other than cannabis and changes in associations of cannabis use with other types of substance use. This study assessed (1) trends in alcohol, nicotine, and nonprescribed pain reliever use and (2) changes in associations of cannabis use with these other substances among young adults in Washington State after nonmedical cannabis legalization.

METHODS

Regression models stratified by age (18-20 vs. 21-25) were used to analyze six annual waves of cross-sectional survey data from a statewide sample from 2014 through 2019 (N = 12,694).

RESULTS

Prevalence of past-month alcohol use, heavy episodic drinking (HED), and cigarette use and prevalence of past-year pain reliever misuse decreased, while the prevalence of past-month e-cigarette use increased since 2016 (the first year assessed). Across years and age groups, the prevalence of substance use other than cannabis was higher among occasional and frequent cannabis users compared to cannabis nonusers. However, associations between both occasional (1-19 days in the prior month) and frequent (20+ days) cannabis use and pain reliever misuse and between frequent cannabis use and HED weakened over time among individuals ages 21-25.

DISCUSSION

Contrary to concerns about spillover effects, implementation of legalized nonmedical cannabis coincided with decreases in alcohol and cigarette use and pain reliever misuse. The weakening association of cannabis use with the use of other substances among individuals ages 21-25 requires further research but may suggest increased importance of cannabis-specific prevention and treatment efforts.

Association Between E-Cigarettes and Asthma in Adolescents: A Systematic Review and Meta-Analysis

INTRODUCTION

Numerous studies have revealed the relationship between E-cigarettes and asthma but have shown inconsistent results. This study systematically evaluated the potential association between E-cigarette use and asthma in adolescents.

METHODS

PubMed, Embase (Ovid), Cochrane Library, and the China Biological Medicine Database were searched for relevant articles published between database inception and February 28, 2021. The quality of included studies was evaluated using the Agency for Healthcare Research and Quality assessment, and a quantitative meta-analysis was conducted to pool outcomes of ORs with 95% CIs.

RESULTS

A total of 10 cross-sectional studies incorporating a total of 483,948 participants were included. All the study participants were middle- and high-school students with a mean age of 15-16 years. The median prevalence of ever E-cigarette use was 11.2% (range=2.2%, 45%), and that of current use was 7.5% (range=2.7%, 25%). Overall, E-cigarette use was associated with significantly higher odds of having asthma (pooled OR=1.31, 95% CI=1.22, 1.42) than nonuse, and both current use (OR=1.36, 95% CI=1.26, 1.48) and ever use (OR=1.20, 95% CI=1.12, 1.28) showed similar associations.

DISCUSSION

This study shows that both current and ever E-cigarette use have significant associations with asthma in adolescents. This knowledge might provide potential evidence for developing primary prevention strategies and serve as a reference for public health policy.

Daily E-cigarette Use and the Surge in JUUL Sales: 2017-2019

OBJECTIVES

To identify how the 2017 rapid surge in sales of JUUL e-cigarettes affected usage among US youth and young adults.

METHODS

Annual surveys in the Population Assessment of Tobacco and Health Study assess tobacco use by product and brand among the US population. We identified 2 cohorts aged 14 to 34 years, 1 with baseline survey in 2014 before the rapid surge of JUUL and the other in 2017 as the surge in JUUL sales was occurring. For 5 age groups, we compared 2-year incidence of first tobacco use and of new-onset daily tobacco use by product, and report levels of dependence.

RESULTS

Sociodemographic variables and rates of experimentation with any tobacco product were similar between cohorts. Among baseline nondaily tobacco users, only those aged 14 to 17 years had an increase in the 2-year incidence of new daily tobacco use (2014 cohort = 4.8%, 95% confidence interval 4.3, 5.5 vs 2017 cohort = 6.3%, 95% confidence interval 5.8-7.0) to rates approaching those in the 1990s. In 2019, three-quarters of new daily tobacco users aged 14 to 17 vaped daily and had e-cigarette dependence scores similar to daily cigarette smokers and older adult e-cigarette vapers. We estimate that about 600 000 Americans aged <21 years used JUUL products daily in 2019, a rate 2.5 times those aged 25 to 34 years.

CONCLUSIONS

The surge in US JUUL sales was associated with a sharp rise in daily e-cigarette vaping and daily tobacco use among US youth, not young adults.

Sex- and genotype-dependent nicotine plus cue-primed reinstatement is enhanced in adolescent Sprague Dawley rats containing the human CHRNA6 3'-UTR polymorphism (rs2304297)

RATIONALE

Large-scale human candidate gene studies have indicated that a genetic variant (rs2304297) in the alpha(α)6 nicotinic acetylcholine receptor (nAChR) subunit, encoded by the CHRNA6 gene, may play a key role in adolescent nicotine addictive behavior. We hypothesized that the polymorphism selectively enhances nicotine + cue-primed reinstatement, but not nicotine- or cue-reinstatement in α6 ^GG (risk) vs. α6 ^CC (non-risk) allele carriers, without having baseline effects on natural rewards.

METHODS

Using CRISPR-Cas9 genomic engineering, we developed a humanized rat line with the human gene variant of the CHRNA6 3'-UTR ^{C 123 G} polymorphism in Sprague-Dawley rats. Genetically modified adolescent male and female rats were food trained under a fixed-ratio (FR)1 schedule of reinforcement and progressively increased to FR5. Animals were implanted with catheters and began nicotine self-administration (15 μg/kg/infusion) at FR5. Upon reaching stable responding, reinforced behavior was extinguished by removal of drug and cues. Reinstatement testing began for cue only, nicotine only, and nicotine + cue in a Latin Square Design. Animals were returned to extinction conditions for 2 days minimum between testing.

RESULTS

For natural food rewards, nicotine self-administration, progressive ratio, and extinction, adolescent male and female (α6 ^GG and α6 ^CC ) rats exhibited equivalent behaviors. Male α6 ^GG rats show enhanced nicotine + cue-primed reinstatement when compared with male α6 ^CC rats. This genotype effect on reinstatement was not seen in female rats.

CONCLUSION

Our findings support the in vivo functional role of the human CHRNA6 3'-UTR SNP genetic variant in sex-dependently enhancing nicotine seeking behavior in adolescent rats. Overall, the findings support clinical and preclinical data highlighting a role of α6 nAChRs mediating sex heterogeneity in substance use and related phenotypes.

Friends and family matter Most: a trend analysis of increasing e-cigarette use among Irish teenagers and socio-demographic, personal, peer and familial associations

BACKGROUND

E-cigarette ever-use and current-use among teenagers has increased worldwide, including in Ireland.

METHODS

We use data from two Irish waves (2015, 2019) of the European School Survey Project on Alcohol and other Drugs (ESPAD) to investigate gender and teenage e-cigarette use (n = 3421 16-year-olds). Using chi-square analyses, we report changes in e-cigarette ever-use, current-use, and associated variables. Using multivariable logistic regression, we analyse the increase in e-cigarette use and socio-demographic, personal, peer and familial associations, focusing on gender differences.

RESULTS

E-cigarette ever-use increased from 23% in 2015 to 37% in 2019, and current-use from 10 to 18%. Compared with 2015, the odds in 2019, of becoming both an e-cigarette ever-user and current-user, were significantly higher for girls than boys (ever-use: AOR 2.67 vs 2.04; current-use: AOR 3.11 vs 1.96). Smoking and e-cigarette use are linked but never-smokers who try e-cigarettes rose significantly from 33 to 67% and those using e-cigarettes to quit smoking decreased significantly from 17 to 3%. Almost two-thirds of respondents (66%) in 2019 said that their reason for trying e-cigarettes was "out of curiosity". Peer smoking is significantly associated with likelihood of e-cigarette ever-use (AOR 6.52) and current-use (AOR 5.45). If "Most/All friends smoke", odds were significantly higher for boys than for girls (ever-use AOR 7.07 vs 6.23; current-use AOR 5.90 vs 5.31). Less parental monitoring is significantly associated with greater e-cigarette ever-use (AOR 3.96) and current-use (4.48), and having parents who usually don't know where their child is on Saturday nights was also associated with significantly higher odds for boys than for girls (ever-use AOR 5.42 vs 3.33; current-use AOR 5.50 vs 3.50).

CONCLUSION

Respondents had significantly higher odds of being e-cigarette ever- and current-users in 2019 compared with 2015. Use is higher among boys but girls are increasingly at risk. Two-thirds had never smoked cigarettes at first e-cigarette use; two-thirds used out of curiosity but few (3%) for smoking cessation. The most prominent risk factors for e-cigarette use were peer- and parent-related, especially so for boys. Interventions that take account of friend and family influences may provide mechanisms for preventing an increasing risk of nicotine addiction.

Association between electronic nicotine delivery systems and electronic non-nicotine delivery systems with initiation of tobacco use in individuals aged < 20 years. A systematic review and meta-analysis

BACKGROUND

This systematic review described the association between electronic nicotine delivery systems and electronic non-nicotine delivery systems (ENDS/ENNDS) use among non-smoking children and adolescents aged <20 years with subsequent tobacco use.

METHODS

We searched five electronic databases and the grey literature up to end of September 2020. Prospective longitudinal studies that described the association between ENDS/ENNDS use, and subsequent tobacco use in those aged < 20 years who were non-smokers at baseline were included. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess risk of bias. Data were extracted by two reviewers and pooled using a random-effects meta-analysis. We generated unadjusted and adjusted risk ratios (ARRs) describing associations between ENDS/ENNDS and tobacco use.

FINDINGS

A total of 36 publications met the eligibility criteria, of which 25 were included in the systematic review (23 in the meta-analysis) after exclusion of overlapping studies. Sixteen studies had high to moderate risk of bias. Ever users of ENDS/ENNDS had over three times the risk of ever cigarette use (ARR 3·01 (95% CI: 2·37, 3·82; p<0·001, I2: 82·3%), and current cigarette use had over two times the risk (ARR 2·56 (95% CI: 1·61, 4·07; p<0·001, I2: 77·3%) at follow up. Among current ENDS/ENNDS users, there was a significant association with ever (ARR 2·63 (95% CI: 1·94, 3·57; p<0·001, I2: 21·2%)), but not current cigarette use (ARR 1·88 (95% CI: 0·34, 10·30; p = 0·47, I2: 0%)) at follow up. For other tobacco use, ARR ranged between 1·55 (95% CI 1·07, 2·23) and 8·32 (95% CI: 1·20, 57·04) for waterpipe and pipes, respectively. Additionally, two studies examined the use of ENNDS (non-nicotine devices) and found a pooled adjusted RR of 2·56 (95% CI: 0·47, 13·94, p = 0.035).

CONCLUSION

There is an urgent need for policies that regulate the availability, accessibility, and marketing of ENDS/ENNDS to children and adolescents. Governments should also consider adopting policies to prevent ENDS/ENNDS uptake and use in children and adolescents, up to and including a ban for this group.

Vaping Associated Cardiac Arrest at School in a Teenager with Anomalous Left Coronary Artery

The prevalence of electronic cigarette use is increasing at an astonishing pace, particularly in the teenage population. While at school, a healthy 13-year-old male experienced a sudden cardiac arrest after vaping multiple times throughout the day. Workup revealed an anomalous left coronary artery originating from the right sinus of Valsalva. Given this patient's underlying anomalous left coronary artery, we suspect that sympathoexcitatory and arrhythmogenic effects of high dose nicotine from vaping led to his cardiovascular collapse. This is the first published case report of a vaping associated cardiac arrest in a patient of this age.

E-Cigarette Use and Adult Cigarette Smoking Cessation: A Meta-Analysis

Objectives. To determine the association between e-cigarette use and smoking cessation.Methods. We searched PubMed, Web of Science Core Collection, and EMBASE and computed the association of e-cigarette use with quitting cigarettes using random effects meta-analyses.Results. We identified 64 papers (55 observational studies and 9 randomized clinical trials [RCTs]). In observational studies of all adult smokers (odds ratio [OR] = 0.947; 95% confidence interval [CI] = 0.772, 1.160) and smokers motivated to quit smoking (OR = 0.851; 95% CI = 0.684, 1.057), e-cigarette consumer product use was not associated with quitting. Daily e-cigarette use was associated with more quitting (OR = 1.529; 95% CI = 1.158, 2.019) and less-than-daily use was associated with less quitting (OR = 0.514; 95% CI = 0.402, 0.665). The RCTs that compared quitting among smokers who were provided e-cigarettes to smokers with conventional therapy found e-cigarette use was associated with more quitting (relative risk = 1.555; 95% CI = 1.173, 2.061).Conclusions. As consumer products, in observational studies, e-cigarettes were not associated with increased smoking cessation in the adult population. In RCTs, provision of free e-cigarettes as a therapeutic intervention was associated with increased smoking cessation.Public Health Implications. E-cigarettes should not be approved as consumer products but may warrant consideration as a prescription therapy.

Age at Initiation of Cigarette Use in a Nationally Representative Sample of US Youth, 2013-2017

IMPORTANCE

Cigarettes are still a commonly used tobacco product among youth despite recent declines in cigarette use.

OBJECTIVE

The aim of this study was to prospectively estimate the age of cigarette use initiation among youth (aged 12-17 years) overall, by sex, and by race/ethnicity.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from waves 1 through 4 of the nationally representative Population Assessment of Tobacco and Health (PATH) study, conducted from September 12, 2013, to January 3, 2018. Two subpopulations of youth were assessed: (1) those nonsusceptible to cigarette use and (2) never users of cigarettes at their first wave of PATH participation. Weighted interval-censoring survival analyses were used to prospectively estimate the age of initiation of cigarette use outcomes. Weighted interval-censoring Cox proportional hazard models were used to estimate differences in the age of initiation by sex and by race/ethnicity. Statistical analyses were performed from October 7, 2019, to May 1, 2020.

EXPOSURES

Differences in the age of initiation by sex and race/ethnicity.

MAIN OUTCOMES AND MEASURES

Age of initiation of susceptibility to cigarette use, ever use, past 30-day use, and fairly regular cigarette use overall, by sex, and by race/ethnicity.

RESULTS

A total of 15 776 youth never users and, among them, 11 022 youth who were nonsusceptible to cigarette use, were included in this study (weighted mean [SE] age, 13.5 [0.01] years; 58.6% [SE, 0.46%] non-Hispanic White; and 51.0% [SE, 0.32%] boys) and 15 776 were never users of cigarettes at their first wave of PATH participation (weighted mean [SE] age, 13.7 [0.01] years; 55.0% [SE, 0.29%] non-Hispanic White; and 51.0% [SE, 0.15%] boys). By age 18 years, among those who were nonsusceptible, 46.2% (95% CI, 44.3%-48.2%) became susceptible to cigarette use. Among never users, 24.4% (95% CI, 22.9%-25.9%) initiated ever cigarette use, 16.4% (95% CI, 15.2%-17.6%) initiated past 30-day cigarette use, and 4.3% (95% CI, 3.9%-4.8%) initiated fairly regular cigarette use. Boys had a higher risk of initiating ever (hazard ratio [HR], 1.21; 95% CI, 1.08-1.36) and past 30-day cigarette use (HR, 1.27; 95% CI, 1.10-1.47) at earlier ages compared with girls. Non-Hispanic White youth had a higher risk of an earlier age of initiation of susceptibility to cigarette use (HR, 0.77; 95% CI, 0.68-0.88), ever use (HR, 0.59; 95% CI, 0.49-0.71), past 30-day use (HR, 0.64; 95% CI, 0.52-0.77), and fairly regular cigarette use (HR, 0.25; 95% CI, 0.14-0.43) compared with non-Hispanic Black youth.

CONCLUSIONS AND RELEVANCE

The results of this cohort study suggest that, despite current interventions and existing laws, a large number of youth initiated cigarette use before the legal age to purchase tobacco products.