Gateway effects and electronic cigarettes

Experimenting first with e-cigarettes versus first with cigarettes and transition to daily cigarette use among adolescents: the crucial effect of age at first experiment

BACKGROUND AND AIMS

Most studies in English-speaking countries have found a positive association between e-cigarette experimentation and subsequent daily tobacco smoking among adolescents. However, this result may not be valid in other cultural contexts; in addition, few studies have assessed whether this association varies with the subject' age at the time of e-cigarette experimentation. This study aimed to estimate the association between experimenting first with e-cigarette (rather than tobacco) and subsequent daily smoking according to age at the time of experimentation.

DESIGN

Secondary analysis; risk ratios (RRs) computed using modified Poisson regressions with inverse probability weighting.

SETTING

A cross-sectional nation-wide representative survey performed in 2017 in France.

PARTICIPANTS

French adolescents (n = 24 111), aged 17 to 18.5 years, who had previously experimented with either e-cigarettes or tobacco.

MEASURES

Exposure was defined as the experimentation with e-cigarettes first (whether or not followed by experimentation with tobacco); the outcome as daily tobacco smoking at the time of data collection. Gender, age, literacy, socio-economic status, pre-exposure repeat school years and experimentation with drunkeness, 3 licit and 8 illicit drugs were adjusted for. Uncertainties about the sequence of events defining exposure were handled by the definition of three patterns of exposure, to avoid a misclassification bias.

FINDINGS

Exposure reduced the risk of transition to daily smoking: RR = 0.58, 95% confidence interval (CI) = 0.54, 0.62. This effect increased in a linear manner with age at exposure (RR = 0.87, 95% CI = 0.78; 0.98 for 1 year, P < 0.001): from RR = 1.30, 95% CI = 1.09; 1.54 at age 9 to RR = 0.38, 95% CI = 0.32; 0.45 at age 17.

CONCLUSIONS

Experimenting with e-cigarettes first (as opposed to tobacco first) appears to be associated with a reduction in the risk of daily tobacco smoking among French adolescents aged 17-18.5, but this risk varies negatively with age at experimentation, and early e-cigarette experimenters are at higher risk.

QuitNic: A Pilot Randomized Controlled Trial Comparing Nicotine Vaping Products With Nicotine Replacement Therapy for Smoking Cessation Following Residential Detoxification

Introduction

The QuitNic pilot trial aimed to test the feasibility of providing a nicotine vaping product (NVP) compared with combination nicotine replacement therapy (NRT) to smokers upon discharge from a smoke-free residential substance use disorder (SUD) treatment service.

Methods

QuitNic was a pragmatic two-arm randomized controlled trial. At discharge from residential withdrawal, 100 clients received telephone Quitline behavioral support and either 12-week supply of NRT or an NVP. Treatment adherence and acceptability, self-reported abstinence, cigarettes smoked per day (CPD), frequency of cravings, and severity of withdrawal symptoms were assessed at 6 and 12 weeks. Results are reported for complete cases and for abstinence outcomes, penalized imputation results are reported where missing is assumed smoking.

Results

Retention on was 63% at 6 weeks and 50% at 12 weeks. At 12 weeks, 68% of the NRT group reported using combination NRT while 96% of the NVP group used the device. Acceptability ratings for the products were high in both groups. At 12 weeks, 14% of the NVP group and 18% of the NRT group reported not smoking at all in the last 7 days. Mean CPD among continued smokers decreased significantly between baseline to 12 weeks in both groups; from 19.91 to 4.72 for the NVP group (p < .001) and from 20.88 to 5.52 in the NRT group (p < .001). Cravings and withdrawal symptoms significantly decreased for both groups.

Conclusions

Clients completing residential withdrawal readily engaged with smoking cessation post-treatment when given the opportunity. Further research is required to identify the most effective treatments postwithdrawal for this population at elevated risk of tobacco-related harm.

Trial registration number

ACTRN12617000849392

Implications

This pilot study showed that smoking cessation support involving options for nicotine replacement and Quitline-delivered cognitive behavioral counseling is attractive to people after they have been discharged from SUD treatment. Both nicotine vaping products and nicotine replacement therapies were highly acceptable and used by participants who reported reductions in cravings for cigarettes and perceptions of withdrawal symptoms and reductions in number of cigarettes smoked. Some participants self-reported abstinence from cigarettes—around one in five reported having quit smoking cigarettes at 12 weeks postdischarge. The results have significant public health implications for providing quit support following discharge from SUD treatment.

Sociodemographic Patterns of Exclusive, Dual, and Polytobacco Use Among U.S. High School Students: A Comparison of Three Nationally Representative Surveys

PURPOSE

This study examines sociodemographic patterns of exclusive/dual/polytobacco use among U.S. high school students using multiple national surveys.

METHODS

Using three national youth surveys (Population Assessment of Tobacco and Health [PATH] Wave 4 [2016-2017], 2017 Youth Risk Behavior Survey, and 2017 National Youth Tobacco Survey), we classified tobacco products into four groups: (1) electronic nicotine delivery systems (ENDS), (2) conventional cigarettes (CCs), (3) other combustible tobacco products, and (4) smokeless tobacco products. We created 16 categories of non/exclusive/dual/polytobacco use within the past 30 days using the four product groups and calculated weighted population prevalence by sex and race/ethnicity (all surveys) and parental education and income (PATH), based on variable availability.

RESULTS

The results from 9,331, 12,407, and 9,699 high school students in PATH, Youth Risk Behavior Survey, and National Youth Tobacco Survey, respectively, largely agreed and pointed to similar conclusions. ENDS was the most prevalent exclusive use product (3.8%-5.2% across surveys), with CCs falling to second or third (1.2%-2.0% across surveys). By sex, exclusive, dual, and poly smokeless tobacco product use were more common for males, whereas exclusive CC use was more common for females. By race/ethnicity, non-Hispanic Whites had a higher prevalence of exclusive ENDS use and ENDS/CC dual use than non-Hispanic Blacks. As income and parental education levels increased from low to high, the prevalence of exclusive CC use decreased, whereas the prevalence of exclusive ENDS use increased.

CONCLUSION

Understanding sociodemographic patterns of tobacco use can help identify groups who may be at greater risk for tobacco-related health outcomes.

Electronic cigarette use and risk of cigarette and smokeless tobacco initiation among adolescent boys: A propensity score matched analysis

INTRODUCTION

Electronic cigarette (e-cigarette) use among adolescents is associated with increased risk of subsequent cigarette smoking initiation in observational research. However, the existing research was not designed to answer causal questions about whether adolescent e-cigarette users would have initiated cigarette smoking if they had never used e-cigarettes. The current study used a causal inference framework to identify whether male adolescent e-cigarette users were at increased risk of initiating cigarette smoking and smokeless tobacco (SLT) use, compared to similar boys who had never used e-cigarettes.

METHODS

Boys from urban and Appalachian Ohio (N = 1220; ages 11-16 years at enrollment) reported use of e-cigarettes, cigarettes, and SLT at baseline and every six months for two years. A propensity score matching design was implemented, matching one e-cigarette user to two similar e-cigarette non-users. This analysis was completed in 25 multiple imputed datasets to account for missing data. Risk ratios (RRs) comparing risk of initiating cigarettes and SLT for e-cigarette users and nonusers were estimated.

RESULTS

Compared to non-users, e-cigarette users were more than twice as likely to later initiate both cigarette smoking (RR = 2.71; 95% CI: 1.89, 3.87) and SLT (RR = 2.42; 95% CI: 1.73, 3.38). They were also more likely to become current (i.e., past 30-day) cigarette smokers (RR = 2.20; 95% CI: 1.33, 3.64) and SLT users (RR = 1.64; 95% CI: 1.01, 2.64).

CONCLUSIONS

Adolescent boys who used e-cigarettes had increased risk of later initiating traditional tobacco products when compared to similar boys who had never used e-cigarettes.

Trends in E-Cigarette Use by Age Group and Combustible Cigarette Smoking Histories, U.S. Adults, 2014-2018

INTRODUCTION

The trends in e-cigarette prevalence and population count of users according to cigarette smoking histories are unknown. These data are needed to inform public health actions against a rapidly changing U.S. e-cigarette market.

METHODS

Data collected between 2014 and 2018 (analyzed in 2020) from cross-sectional, nationally representative National Health Interview Surveys were used to estimate current e-cigarette prevalence, adjusted prevalence differences (percentage points), and population counts of users. Analyses were stratified by age group (younger, 18-29 years, n=25,445; middle age, 30-49 years, n=47,745; older, ≥50 years, n=79,517) and cigarette smoking histories (current smokers, recent quitters [quit <1 year ago], near-term quitters [quit 1-8 years ago], long-term quitters [quit >8 years ago], never smokers).

RESULTS

Among younger adults, e-cigarette use increased in all groups of smokers, with notable increases between 2014 and 2018 among never smokers (1.3%-3.3%, adjusted prevalence difference=2%, p<0.001) and near-term quitters (9.1%-19.2%, adjusted prevalence difference=8.8%, p=0.024). Conversely, the only substantial increase in e-cigarette use between 2014 and 2018 among middle-aged (5.8%-14.4%, adjusted prevalence difference=8.2%, p<0.001) and older (6.3%-9.5%, adjusted prevalence difference=3.3%, p=0.045) adults was among near-term quitters. The largest absolute population increase in e-cigarette users between 2014 and 2018 was among younger-adult never smokers (0.49-1.35 million), followed by near-term quitters among middle-aged (0.36-0.95 million), younger (0.23-0.57 million), and older (0.35-0.50 million) adults.

CONCLUSIONS

The continuous increase among younger-adult never smokers suggests a rise in primary nicotine initiation with e-cigarettes. The concomitant increase among near-term quitters of all age groups suggests continuing e-cigarette use among smokers who may have switched from cigarettes previously.

E-cigarette use and cigarette smoking initiation among Australian women who have never smoked

INTRODUCTION AND AIM

Evidence regarding the association between e-cigarette use and subsequent initiation of smoking mostly relates to the US population. In Australia, no studies are available investigating the association between the uses of e-cigarettes and smoking initiation among young adults who have never smoked. This study aimed to determine the association between lifetime e-cigarette use and subsequent initiation of cigarette smoking among tobacco-naïve Australian women aged 20-27.

DESIGN AND METHODS

The current study used data (n = 5398) from the third (2015) and fourth (2016) surveys collected from a cohort of Australian women born in 1989-1995 who participated in the Australian Longitudinal Study on Women's Health. Multivariable logistic regression was used to identify the association between lifetime e-cigarette use at the baseline survey and initiation of cigarette smoking (smoked 100 cigarettes or more in the last year) at the follow up adjusting for possible confounders. Effects were expressed as odds ratios with 95% confidence interval.

RESULTS

The mean (± SD) age of the study participants at baseline (third survey) was 22.5 (±1.7). Ever e-cigarette use at baseline was positively associated with smoking initiation at follow up (adjusted odds ratio 3.71; 95% confidence interval 2.33, 5.93). History of depression, binge drinking and higher childhood adversity score were also risk factors for subsequent smoking initiation in the follow up.

DISCUSSION AND CONCLUSIONS

This study identified a strong association between e-cigarette use and subsequent initiation of smoking. Enforcing the existing restriction of sale and supply of e-liquid containing nicotine is essential to prevent never smokers from nicotine addiction via e-cigarettes.

Predictors of electronic cigarette use among Swedish teenagers: a population-based cohort study

OBJECTIVES

The aim was to identify predictors of electronic cigarette (e-cigarette) use among teenagers.

DESIGN AND SETTING

A prospective population-based cohort study of schoolchildren in northern Sweden.

PARTICIPANTS

In 2006, a cohort study about asthma and allergic diseases among schoolchildren started within the Obstructive Lung Disease in Northern Sweden studies. The study sample (n=2185) was recruited at age 7-8 years, and participated in questionnaire surveys at age 14-15 and 19 years. The questionnaire included questions about respiratory symptoms, living conditions, upper secondary education, physical activity, diet, health-related quality of life, parental smoking and parental occupation. Questions about tobacco use were included at age 14-15 and 19 years.

PRIMARY OUTCOME

E-cigarette use at age 19 years.

RESULTS

At age 19 years, 21.4% had ever tried e-cigarettes and 4.2% were current users. Among those who were daily tobacco smokers at age 14-15 years, 60.9% had tried e-cigarettes at age 19 years compared with 19.1% of never-smokers and 34.0% of occasional smokers (p<0.001). Among those who had tried e-cigarettes, 28.1% were never smokers both at age 14-15 and 19 years, and 14.4% were never smokers among the current e-cigarette users. In unadjusted analyses, e-cigarette use was associated with daily smoking, use of snus and having a smoking father at age 14-15 years, as well as with attending vocational education, physical inactivity and unhealthy diet. In adjusted analyses, current e-cigarette use was associated with daily tobacco smoking at age 14-15 years (OR 6.27; 95% CI 3.12 to 12.58), attending a vocational art programme (OR 2.22; 95% CI 1.04 to 4.77) and inversely associated with eating a healthy diet (OR 0.74; 95% CI 0.59 to 0.92).

CONCLUSIONS

E-cigarette use was associated with personal and parental tobacco use, as well as with physical inactivity, unhealthy diet and attending vocational upper secondary education. Importantly, almost one-third of those who had tried e-cigarettes at age 19 years had never been tobacco smokers.

Smoking Intention and Progression From E-Cigarette Use to Cigarette Smoking

OBJECTIVES

To investigate whether the prospective association between electronic cigarette (e-cigarette) use and cigarette smoking is dependent on smoking intention status.

METHODS

Waves 2 and 3 data of the Population Assessment of Tobacco and Health (PATH) Study, a US nationally representative prospective cohort study of tobacco use. Data were collected in 2014-2015 (wave 2) and 2015-2016 (wave 3) and analyzed in 2019.

RESULTS

At wave 2, 12.8% of adolescent never-smokers of conventional cigarettes had intention to smoke and 8.5% had ever used an e-cigarette. At wave 3, 3.2% had ever smoked a cigarette. Both smoking intention and ever using e-cigarettes at wave 2 were positively associated with cigarette smoking at wave 3 (adjusted odds ratio [aOR] = 3.03; 95% confidence interval [CI] = 1.97-4.68, P < .001; aOR = 4.62, 95% CI = 2.87-7.42, P < .001, respectively). The interaction between smoking intention and ever using e-cigarettes was significant (aOR = 0.34, 95% CI = 0.18-0.64, P < .01). Among adolescents who had expressed intention to smoke conventional cigarettes at wave 2, the odds of cigarette smoking at wave 3 did not significantly differ for e-cigarette users and never e-cigarette users (aOR = 1.57; 95% CI 0.94-2.63; P = .08). Among adolescents who had no intention to smoke at wave 2, e-cigarette users, compared with never e-cigarette users, had >4 times the odds of cigarette smoking (aOR = 4.62; 95% CI 2.87-7.42; P < .0001).

CONCLUSIONS

E-cigarette use is associated with increased odds of cigarette smoking among adolescents who had no previous smoking intention. E-cigarette use may create intention to smoke and/or nicotine use disorder that lead to onset of cigarette smoking.

Smoking Intention and Progression From E-Cigarette Use to Cigarette Smoking

OBJECTIVES

To investigate whether the prospective association between electronic cigarette (e-cigarette) use and cigarette smoking is dependent on smoking intention status.

METHODS

Waves 2 and 3 data of the Population Assessment of Tobacco and Health (PATH) Study, a US nationally representative prospective cohort study of tobacco use. Data were collected in 2014-2015 (wave 2) and 2015-2016 (wave 3) and analyzed in 2019.

RESULTS

At wave 2, 12.8% of adolescent never-smokers of conventional cigarettes had intention to smoke and 8.5% had ever used an e-cigarette. At wave 3, 3.2% had ever smoked a cigarette. Both smoking intention and ever using e-cigarettes at wave 2 were positively associated with cigarette smoking at wave 3 (adjusted odds ratio [aOR] = 3.03; 95% confidence interval [CI] = 1.97-4.68, P < .001; aOR = 4.62, 95% CI = 2.87-7.42, P < .001, respectively). The interaction between smoking intention and ever using e-cigarettes was significant (aOR = 0.34, 95% CI = 0.18-0.64, P < .01). Among adolescents who had expressed intention to smoke conventional cigarettes at wave 2, the odds of cigarette smoking at wave 3 did not significantly differ for e-cigarette users and never e-cigarette users (aOR = 1.57; 95% CI 0.94-2.63; P = .08). Among adolescents who had no intention to smoke at wave 2, e-cigarette users, compared with never e-cigarette users, had >4 times the odds of cigarette smoking (aOR = 4.62; 95% CI 2.87-7.42; P < .0001).

CONCLUSIONS

E-cigarette use is associated with increased odds of cigarette smoking among adolescents who had no previous smoking intention. E-cigarette use may create intention to smoke and/or nicotine use disorder that lead to onset of cigarette smoking.

Mostly harmless regulation? Electronic cigarettes, public policy, and consumer welfare

Electronic cigarettes are a less harmful alternative to combustible cigarettes. We analyze data on e-cigarette choices in an online experimental market. Our data and mixed logit model capture two sources of consumer optimization errors: overestimates of the relative risks of e-cigarettes and present bias. Our novel data and policy analysis make three contributions. First, our predictions about e-cigarette use under counterfactual policy scenarios provide new information about current regulatory tradeoffs. Second, we provide empirical evidence about the role consumer optimization errors play in tobacco product choices. Third, we contribute to behavioral welfare analysis of policies that address individual optimization errors. Compared with standard cost-benefit analysis, our behavioral welfare economics analysis leads to much larger estimates of the costs of policies that discourage e-cigarette use or the benefits of policies that encourage e-cigarette use.

Withdrawal Symptoms From E-Cigarette Abstinence Among Former Smokers: A Pre-Post Clinical Trial

INTRODUCTION

The major aim of this study was to test whether abstinence from e-cigarettes causes withdrawal symptoms in former smokers.

METHODS

We conducted an unblinded, within-participants, pre-post clinical trial in which 109 former smokers who were current daily electronic cigarette (e-cigarette) users used their own e-cigarette for 7 days followed by 6 days of biologically confirmed abstinence engendered via an escalating contingency payment system. Participants monitored symptoms of nicotine withdrawal daily via an Interactive Voice Response system. They also attended three laboratory visits per week for carbon monoxide and cotinine testing to verify abstinence.

RESULTS

Half of participants completely abstained for a week. All the Diagnostic and Statistical Manual, Fifth Edition (DSM-5) tobacco withdrawal symptoms, craving for e-cigarettes, craving for tobacco cigarettes, and the four possible new withdrawal symptoms (anhedonia, impulsivity, mood swings, and positive affect) increased during abstinence. Weight increased and heart rate decreased with abstinence. Symptoms showed the prototypical inverted U time pattern of a withdrawal state. The magnitude of withdrawal appeared to be somewhat less than that in a prior study of abstinent daily tobacco cigarette smokers. More severe withdrawal on the first 2 days of abstinence did not predict abstinence on the last day of the study.

CONCLUSIONS

Former smokers who are daily e-cigarette users transfer physical dependence on tobacco cigarettes to dependence on e-cigarettes. The severity of withdrawal from e-cigarettes appears to be only somewhat less than that from daily tobacco cigarette use. Replication tests that include placebo controls, testing for pharmacological specificity, and including never-smokers, non-daily e-cigarette users and dual users are indicated.

IMPLICATIONS

Our results indicate e-cigarettes can maintain physical dependence. This adverse effect should be included in any risk vs. benefit calculation. Also, potential and current e-cigarette users should be informed that abrupt cessation of e-cigarettes can cause withdrawal symptoms.

TRIAL REGISTRATION

NCT02825459.

Electronic cigarettes: A position statement from the Thoracic Society of Australia and New Zealand

The TSANZ develops position statements where insufficient data exist to write formal clinical guidelines. In 2018, the TSANZ addressed the question of potential benefits and health impacts of electronic cigarettes (EC). The working party included groups focused on health impacts, smoking cessation, youth issues and priority populations. The 2018 report on the Public Health Consequences of E-Cigarettes from the United States NASEM was accepted as reflective of evidence to mid-2017. A search for papers subsequently published in peer-reviewed journals was conducted in August 2018. A small number of robust and important papers published until March 2019 were also identified and included. Groups identified studies that extended, modified or contradicted the NASEM report. A total of 3793 papers were identified and reviewed, with summaries and draft position statements developed and presented to TSANZ membership in April 2019. After feedback from members and external reviewers, a collection of position statements was finalized in December 2019. EC have adverse lung effects and harmful effects of long-term use are unknown. EC are unsuitable consumer products for recreational use, part-substitution for smoking or long-term exclusive use by former smokers. Smokers who require support to quit smoking should be directed towards approved medication in conjunction with behavioural support as having the strongest evidence for efficacy and safety. No specific EC product can be recommended as effective and safe for smoking cessation. Smoking cessation claims in relation to EC should be assessed by established regulators.

Genetic susceptibility to nicotine addiction: Advances and shortcomings in our understanding of the CHRNA5/A3/B4 gene cluster contribution

Over the last decade, robust human genetic findings have been instrumental in elucidating the heritable basis of nicotine addiction (NA). They highlight coding and synonymous polymorphisms in a cluster on chromosome 15, encompassing the CHRNA5, CHRNA3 and CHRNB4 genes, coding for three subunits of the nicotinic acetylcholine receptor (nAChR). They have inspired an important number of preclinical studies, and will hopefully lead to the definition of novel drug targets for treating NA. Here, we review these candidate gene and genome-wide association studies (GWAS) and their direct implication in human brain function and NA-related phenotypes. We continue with a description of preclinical work in transgenic rodents that has led to a mechanistic understanding of several of the genetic hits. We also highlight important issues with regards to CHRNA3 and CHRNB4 where we are still lacking a dissection of their role in NA, including even in preclinical models. We further emphasize the use of human induced pluripotent stem cell-derived models for the analysis of synonymous and intronic variants on a human genomic background. Finally, we indicate potential avenues to further our understanding of the role of this human genetic variation. This article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology'.

Youth vaping and smoking and parental vaping: a panel survey

BACKGROUND

Concerns remain about potential negative impacts of e-cigarettes including possibilities that: youth e-cigarette use (vaping) increases risk of youth smoking; and vaping by parents may have impacts on their children's vaping and smoking behaviour.

METHODS

With panel data from 3291 youth aged 10-15 years from the 7th wave of the UK Understanding Society Survey (2015-2017), we estimated effects of youth vaping on youth smoking (ever, current and past year initiation), and of parental vaping on youth smoking and vaping, and examined whether the latter differed by parental smoking status. Propensity weighting was used to adjust for measured confounders and estimate average effects of vaping for all youth, and among youth who vaped. E-values were calculated to assess the strength of unmeasured confounding influences needed to negate our estimates.

RESULTS

Associations between youth vaping and youth smoking were attenuated considerably by adjustment for measured confounders. Estimated average effects of youth vaping on youth smoking were stronger for all youth (e.g. OR for smoking initiation: 32.5; 95% CI: 9.8-107.1) than among youth who vaped (OR: 4.4; 0.6-30.9). Relatively strong unmeasured confounding would be needed to explain these effects. Associations between parental vaping and youth vaping were explained by measured confounders. Estimates indicated effects of parental vaping on youth smoking, especially for youth with ex-smoking parents (e.g. OR for smoking initiation: 11.3; 2.7-46.4) rather than youth with currently smoking parents (OR: 1.0; 0.2-6.4), but these could be explained by relatively weak unmeasured confounding.

CONCLUSIONS

While measured confounding accounted for much of the associations between youth vaping and youth smoking, indicating support for underlying propensities, our estimates suggested residual effects that could only be explained away by considerable unmeasured confounding or by smoking leading to vaping. Estimated effects of youth vaping on youth smoking were stronger among the general youth population than among the small group of youth who actually vaped. Associations of parental vaping with youth smoking and vaping were either explained by measured confounding or could be relatively easily explained by unmeasured confounding.

Exploring Associations between Susceptibility to the Use of Electronic Nicotine Delivery Systems and E-Cigarette Use among School-Going Adolescents in Rural Appalachia

Electronic nicotine delivery systems (ENDS) use, including e-cigarettes, has surpassed the use of conventional tobacco products. Emerging research suggests that susceptibility to e-cigarette use is associated with actual use among adolescents. However, few studies exist involving adolescents in high-risk, rural, socioeconomically distressed environments. This study examines susceptibility to and subsequent usage in school-going adolescents in a rural distressed county in Appalachian Tennessee using data from an online survey (N = 399). Relying on bivariate analyses and logistic regression, this study finds that while 30.6% of adolescents are ever e-cigarette users, 15.5% are current users. Approximately one in three adolescents are susceptible to e-cigarettes use, and susceptibility is associated with lower odds of being a current e-cigarette user (OR = 0.03; CI: 0.01–0.12; p < 0.00). The age of tobacco use initiation was significantly associated with decreased current use of e-cigarettes (OR = 0.89; CI: 0.83–0.0.97; p < 0.01). Overall, the results of this exploratory study suggest the need for larger studies to identify unique and generalizable factors that predispose adolescents in this high-risk rural, socioeconomically disadvantaged region to ENDS use. Nevertheless, this study offers insight into e-cigarette usage among U.S adolescents in rural, socioeconomically disadvantaged environments and provides a foundation for a closer examination of this vulnerable population.

Initial use of tobacco or marijuana and later use profiles in young adults

INTRODUCTION

Given the relatively limited literature regarding risk factors for progression of alternative tobacco and marijuana use, this study examined initially-used tobacco or marijuana products and psychosocial risk factors such as adverse childhood events (ACEs), mental health (depression, ADHD), and parental substance use, in relation to young adult lifetime and current (past 30-day) tobacco and marijuana use.

METHODS

Using cross-sectional data from a 2014–2016 study of 3418 young adult college students in Georgia, we analyzed lifetime and current use of various tobacco products (cigarettes, cigar products, smokeless tobacco, e-cigarettes, hookah) and marijuana among lifetime tobacco or marijuana users (N=1451) in relation to initially-used product as well as sociodemographic characteristics and psychosocial risk factors.

RESULTS

Multivariable analyses indicated that more products ever used correlated with cigarettes being first used (vs cigars, B=-0.66; e-cigarettes, OR=-1.33; hookah, B=-0.99; and marijuana, B=-1.05; p<0.001), as well as being older (B=0.06), male (B=-0.72) and White (vs Black, B=-0.30; or Asian, B=-0.60), more adverse childhood events (ACEs, B=0.07), and parental marijuana use (B=0.47; p<0.05). Currently-used products correlated with cigarettes being first used (vs cigars, B=-0.18; e-cigarettes, B=-0.37; and hookah, B=-0.18; p<0.05), being younger (B=-0.04), male (B=-0.15), more depressive symptoms (B=0.01), and parental marijuana use (B=0.40; p<0.05). Current cigarette, smokeless tobacco, hookah and marijuana use demonstrated specificity to initially-used products.

CONCLUSIONS

Initially-used products, specifically cigarettes, with well-documented and communicated risks, correlated with using more products subsequently among young adults, underscoring needed research on such risks and risk communication, and early intervention strategies.

How Is Use of Electronic Cigarettes Related to Conventional Cigarette Use? A Qualitative Study among Korean American Young Adults

Given the growing popularity of e-cigarettes in the United States, there is a need to understand the relationship between conventional and electronic cigarette use among Korean American young adults. Thus, this study aimed to explore Korean American young adults' experience of electronic cigarettes and its association with use of conventional cigarettes. This study employed an exploratory qualitative design. Individual interviews were conducted with 15 Korean American young adults aged between 18 and 25 years who reported having smoked at least one conventional cigarette per day for the past 6 months. Interview data were subjected to thematic analysis in order to gain an in-depth understanding of the interconnection between e-cigarette and conventional cigarette use. Data analysis revealed three themes involving reasons for buying, using, and stopping use of e-cigarettes, each of which had several sub-themes. Study results suggest that experience of e-cigarettes was related to conventional cigarette use. Thus, the experience of e-cigarettes as well as conventional cigarettes should be considered in designing smoking cessation interventions for Korean American young adults.

Disentangling Within- and Between-Person Effects of Shared Risk Factors on E-cigarette and Cigarette Use Trajectories From Late Adolescence to Young Adulthood

BACKGROUND

Longitudinal studies report associations between use of electronic cigarettes (ECs) and cigarettes over time among young people, but do not distinguish within- from between-person effects, which complicates interpretation of findings. Further, the role of shared risk factors, such as substance use and mental health, in explaining longitudinal associations between EC and cigarette use remains unclear. This study used within- and between-person analyses to assess longitudinal associations between youths' EC and cigarette use and shared risk factors.

METHODS

Between 2015 and 2017, 2039 youths completed three Web-based surveys, allowing us to model EC and cigarette use from ages 16 to 20. Auto-regressive latent growth models with structured residuals (ALT-SR) examined both between-person and within-person associations between past-month frequency of EC use, cigarette use, and third variables (alcohol and marijuana use, mental health symptoms) over time.

RESULTS

Models revealed robust reciprocal associations between EC and cigarette use, such that more frequent EC use at one time predicted more frequent cigarette use at the subsequent time, and vice versa. Between-person analyses showed associations between shared risk factors and both EC and cigarette use. However, shared risk factors did not predict frequency of subsequent EC and cigarette use in within-person analyses.

CONCLUSIONS

Findings add to a growing body of research suggesting that EC use among youth is prospectively associated with progression toward greater cigarette use. Shared risk factors may help explain differences in EC and cigarette use patterns between young people, but do not appear to influence longitudinal trajectories of EC and cigarette use within individuals.

IMPLICATIONS

This study examined within- and between-person associations between e-cigarette use, cigarette use, and shared risk factors (alcohol use, marijuana use, mental health symptoms) in a longitudinal cohort of youths. Within- and between-person analyses revealed reciprocal prospective associations between e-cigarette and cigarette use, suggesting a progression toward more frequent use of both products over time. The shared risk factors examined here did not affect escalations in e-cigarette or cigarette use over time within individuals, but likely influence which youths use these products. Findings add to a growing body of evidence suggesting that e-cigarette use increases subsequent cigarette use in young people.

E-Cigarette Use and Regular Cigarette Smoking Among Youth: Population Assessment of Tobacco and Health Study (2013-2016)

INTRODUCTION

This study examines the association between current e-cigarette use at baseline and regular cigarette smoking at follow-up among U.S. youth.

METHODS

A longitudinal analysis of youth (aged 12-17 years) data from Waves 1-3 of the Population Assessment of Tobacco and Health Study (2013-2016) was conducted between January 2019 and December 2019. Youth who reported past-30-day current e-cigarette use at baseline were identified and followed for regular cigarette smoking (≥20 days) at follow-up.

RESULTS

Compared with noncurrent e-cigarette users at baseline, current e-cigarette users (cigarette nonsmokers) had 5.0 (95% CI=1.9, 12.8) times higher odds of becoming regular cigarette smokers 1 year later. Additionally, there was a direct linear relationship between the number of days of e-cigarette use at baseline and the number of days of cigarette smoking 1 year later.

CONCLUSIONS

Current e-cigarette use among U.S. youth is associated with higher odds of transitioning to regular cigarette smoking, likely reflecting robust transitions rather than experimentation. These results suggest that promoting e-cigarettes as the current practice for tobacco harm reduction will likely have the unintended consequence of initiating youth cigarette smokers.

Comparing Factors Related to Any Conventional Cigarette Smokers, Exclusive New Alternative Product Users, and Non-Users among Japanese Youth: A Nationwide Survey

The impact of heated-tobacco-products (HTPs) and electronic cigarettes (e-cigarettes) on youth is a controversial public health issue, as it is unknown whether alternative products result in more youth using such products or smoking. In Japan, e-cigarettes with nicotine are prohibited, but e-cigarettes without nicotine are available. HTPs are marketed as tobacco products. Within this unique context, we aimed to compare any conventional cigarette smokers (including those who also used alternative products) with exclusive users of alternative products and examine factors relating to their use in Japan. In 2017, 22,275 students in grades 7–9 (age 12–15) and 42,142 in grades 10–12 (age 15–18) nationwide were surveyed. Overall, 1.8% were current users of any of the three products over the last month. Multivariable analysis revealed that risk factors for alternative product use were the same as those for cigarette use. Among all users, exclusive new product users were more likely to participate in club activities and intend to continue to higher education; any conventional cigarette users (including those who also used alternative products) were more likely to be exposed to secondhand smoke at home and to drink alcohol. Reducing adult smoking and disseminating health education remain relevant as strategies for preventing adolescents’ future tobacco use.

Electronic cigarette advertising and teen smoking initiation

INTRODUCTION

The objective of this study was to investigate the associations between recall of exposure to e-cigarette advertisements and initial use of e-cigarettes, conventional cigarettes and hookahs one year later among German adolescents.

METHODS

Longitudinal school-based survey with a sample of 4,529 German adolescents (mean age = 12.5 years, SD = 1.55). Baseline assessment took place in the fall/winter 2016/2017, and a follow-up assessment 12 months later. Exposure to e-cigarette advertisements was measured at baseline with self-rated contact frequency to three advertising images. Multilevel mixed-effect logistic regression models were used to assess associations between exposure to e-cigarette advertisements at baseline and adolescents' initiation of e-cigarette, smoking and hookah use one year later.

RESULTS

About 14% (N = 472) baseline never-users initiated e-cigarette use within one year, about 11% (N = 384) initiated cigarette use, and 12% (N = 406) used a hookah for the first time within the observation period. After statistical control for age, gender, school type, subjective socioeconomic status, sensation seeking, lifetime smoking behavior and peer substance use, adolescents with higher contact to e-cigarette advertisements had higher proportion of subsequent e-cigarette (aOR = 1.37 (CI = 1.04-1.81) p = .024), cigarette (aOR = 1.44 (CI = 1.09-1.91) p = .010), and hookah use (aOR = 1.82 (CI = 1.37-2.42) p < .001).

CONCLUSIONS

This longitudinal study demonstrates that exposure to e-cigarette advertisements may increase the likelihood of initial use of e-cigarettes, cigarettes, and hookahs. Findings raise concerns about e-cigarette marketing regulations in Germany, and about the broader impact of e-cigarette advertising on traditional smoking.

Are e-cigarettes reviving the popularity of conventional smoking among Taiwanese male adolescents? A time-trend population-based analysis for 2004-2017

INTRODUCTION

In Taiwan, national tobacco use surveys show that e-cigarette use has increased since 2014 among youth, while, at the same time, conventional cigarette smoking has continuously decreased. The purpose of this study is to examine whether the increased popularity of e-cigarettes has undermined this favourable declining trend for cigarette smoking.

METHODS

We examined conventional cigarette and e-cigarette prevalence among male high school students (aged 16-18 years) and adults from 2004 to 2017, using data from cross-sectional nationally representative surveys. Applying interrupted time series analysis, we assessed whether there was a change in trend in 2014, when e-cigarette use started to gain popularity from long-term trends in prior years (2004-2013).

RESULTS

E-cigarette use prevalence increased from 2.5% in 2014 to 6.4% in 2017 among male high school students but was negligible among male adults, declining from 1.4% in 2015 to 0.8% in 2017. The annual relative decline in the cigarette smoking rate after e-cigarettes started to gain popularity was greater (-10%) than the long-term trend (-2%) among high school students. Among adults, the change in trend over time after e-cigarettes started to gain popularity was not significant (ie, not significantly different from 0).

CONCLUSIONS

The increased popularity of e-cigarettes since 2014 is associated with a greater decline in youth smoking, compared with previous years. On the contrary, e-cigarette use has remained very low among Taiwanese male adults and no additional impact on the conventional smoking trend is found.

Trendy e-cigarettes enter Europe: chemical characterization of JUUL pods and its aerosols

The popularity and the high nicotine content of the American pod e-cigarette JUUL have raised many concerns. To comply with European law, the nicotine concentration in the liquids of the European version, which has been recently released on the market, is limited to below 20 mg/mL. This limit can possibly be circumvented by technological adjustments that increase vaporization and consequently, elevate nicotine delivery. In this study, we compare vapor generation and nicotine delivery of the initial European version, a modified European version, and the original American high-nicotine variant using a machine vaping set-up. Additionally, benzoic acid and carbonyl compounds are quantified in the aerosol. Further, concentrations of nicotine, benzoic acid, propylene glycol, and glycerol, along with the density and pH value of JUUL e-liquids have been assessed. Whereas the initial European version did not compensate for the low nicotine content in the liquid, we provide evidence for an increased vaporization by the modified European version. As a consequence, nicotine delivery per puff approximates the American original. Notably, this is not associated with an increased generation of carbonyl compounds. Our data suggest a similar addictiveness of the enhanced European version and the original American product.

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.

Does the gateway theory justify a ban on nicotine vaping in Australia?

Australia bans the sale, possession and use of liquid nicotine for vaping. One of the major arguments used to justify Australia's policy is that the availability of nicotine vaping products will lead a substantial number of young people who would otherwise not have smoked cigarettes to take up regular smoking (the gateway theory). In this article, we provide a critical analysis of the use of the gateway theory to justify Australian policy. We argue first that the evidence that vaping serves as a gateway to smoking is unconvincing. Smoking more often precedes vaping than vice versa, regular vaping by never-smokers is rare and the association is more plausibly explained by a common liability model. Second, we argue that even if the evidence were stronger it would not justify a ban on the sale of nicotine to adult smokers because there are other ways of preventing adolescent vaping that do not require a ban. We describe an alternative regulatory model for Australia that would address legitimate concerns about preventing adolescent uptake while allowing adult smokers to access these products for cessation or as an alternative to smoking cigarettes.

Socioeconomic patterning of vaping by smoking status among UK adults and youth

BACKGROUND

Smoking contributes significantly to socioeconomic health inequalities. Vaping has captured much interest as a less harmful alternative to smoking, but may be harmful relative to non-smoking. Examining inequalities in vaping by smoking status, may offer insights into potential impacts of vaping on socioeconomic inequalities in health.

METHODS

Data were from 3291 youth (aged 10-15) and 35,367 adults (aged 16+) from wave 7 (2015-17) of the UK Household Longitudinal Study. In order to adjust for biases that could be introduced by stratifying on smoking status, marginal structural models were used to estimate controlled direct effects of an index of socioeconomic disadvantage (incorporating household education, occupation and income) on vaping by smoking status (among adults and youth), adjusting for relevant confounders and for selection into smoking states. We also estimated controlled direct effects of socioeconomic disadvantage on being an ex-smoker by vaping status (among adult ever-smokers; n = 18,128).

RESULTS

Socioeconomic disadvantage was associated with vaping among never smoking youth (OR for a unit increase in the socioeconomic index: 1.17; 95%: 1.03-1.34), and among ex-smoking adults (OR: 1.17; 95% CI: 1.09-1.26), with little to no association among never smoking (OR: 0.98; 95% CI: 0.91-1.07) and current smoking (OR: 1.00; 95% CI: 0.93-1.07) adults. Socioeconomic disadvantage was also associated with reduced odds of being an ex-smoker among adult ever-smokers, but this association was moderately weaker among those who vaped (OR: 0.88; 95% CI: 0.82-0.95) than those who did not (OR: 0.82; 95% CI: 0.80-0.84; p-value for difference = 0.081).

CONCLUSIONS

Inequalities in vaping among never smoking youth and adult ex-smokers, suggest potential to widen health inequalities, while weaker inequalities in smoking cessation among adult vapers indicate e-cigarettes could help narrow inequalities. Further research is needed to understand the balance of these opposing potential impacts, and how any benefits can be maximised whilst protecting the vulnerable.

Nicotine vaping products as a harm reduction tool among smokers: Review of evidence and implications for pharmacy practice

With the growing popularity and use of nicotine vaping products (NVPs, also known as e-cigarettes) as a way to quit smoking, pharmacy staff are frequently asked by smokers for advice about NVPs. In Australia, there are currently no clear guidelines or policy statements provided by any of the professional organisations for pharmacists on how they should handle customer enquiries about NVPs, or on extemporaneous compounding of prescriptions for nicotine solution for use in NVPs as a smoking cessation aid. This commentary summarises the current evidence surrounding the safety and efficacy of NVPs, the Australian regulatory landscape, and provides a guide for pharmacy staff to use in discussions with customers regarding NVPs. Evidence strongly points to NVPs being considerably less harmful than smoking tobacco cigarettes and that they can be effective for smoking cessation. The maximum benefit from using NVPs as a harm reduction tool, however, will only be realised if smokers completely stop smoking rather than using NVPs as a partial substitute, because even low level smoking still confers substantial health risk. Vaping products containing nicotine are illegal to sell in Australia but users can still legally access nicotine e-liquid through some limited pathways if they hold a valid prescription from a registered medical practitioner. It is important that pharmacy staff keep abreast of the current evidence surrounding these products and provide evidence-based advice to customers.

Association of Electronic Cigarette Regulations With Electronic Cigarette Use Among Adults in the United States

IMPORTANCE

Millions of Americans use electronic cigarettes (e-cigarettes). A growing number of state and local governments have started to draft and implement laws regarding the sale, marketing, and use of e-cigarettes. The association of US state regulations regarding e-cigarettes with e-cigarette use remains unknown.

OBJECTIVE

To examine the association of US state regulations regarding e-cigarettes with current e-cigarette use among adults in the United States.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included adults aged 18 years or older from the 2016 and 2017 Behavioral Risk Factor Surveillance System, which is a nationwide, telephone-administered survey that collects state-representative data on health-related risk behaviors, chronic health conditions, and use of preventive services. Data analysis was performed from February 1, 2019, to April 31, 2019.

EXPOSURES

United States state laws regulating e-cigarette use, including prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars; requiring retailers to purchase a license to sell e-cigarettes; prohibiting self-service displays of e-cigarettes; prohibiting sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and e-cigarette taxes.

MAIN OUTCOMES AND MEASURES

Current use of e-cigarettes.

RESULTS

Among 894 997 participants aged 18 years or older (503 688 women [51.3%], 679 443 non-Hispanic white [62.6%], 71 730 non-Hispanic black [16.3%], 69 823 Hispanic [11.4%], and 74 001 non-Hispanic other races [9.8%]), 28 907 (weighted prevalence, 4.4%) were currently using e-cigarettes. The age-standardized weighted prevalence of current e-cigarette use varied across US states and territories, from 1.0% in Puerto Rico to 6.2% in Guam. After adjustment for demographic, socioeconomic, and lifestyle factors, including conventional cigarette use, the odds ratios of current e-cigarette use were 0.90 (95% CI, 0.83-0.98) for state laws prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars; 0.90 (95% CI, 0.85-0.95) for state laws requiring retailers to purchase a license to sell e-cigarettes; 1.04 (95% CI, 0.99-1.09) for state laws prohibiting self-service displays of e-cigarettes; 0.86 (95% CI, 0.74-0.99) for state laws prohibiting sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and 0.89 (95% CI, 0.83-0.96) for state laws applying taxes to e-cigarettes.

CONCLUSIONS AND RELEVANCE

These findings suggest that several state regulations regarding e-cigarettes may be associated with reduced e-cigarette use among US adults.

The impact of the point-of-sale tobacco display ban on young people in Scotland: before-and-after study

Background

Tobacco displays at point of sale have been shown to increase young people’s pro-smoking attitudes, susceptibility to smoking and smoking initiation. In Scotland, legislation that prohibited tobacco point-of-sale displays was implemented in large stores (i.e. those > 280 m2) in April 2013 and in small retailers in April 2015.

Objective

To assess the impact of the point-of-sale tobacco display ban on young people’s exposure to tobacco advertising, their attitudes to smoking and smoking susceptibility, and their risk of smoking initiation.

Design

Multimodal before-and-after study design using mixed methods to collect data at baseline (2013) and then longitudinally for 4 years.

Setting

Four main study communities in the central belt of mainland Scotland, UK, purposively selected to reflect two levels of urbanity (urban vs. small town) and two levels of deprivation (high vs. medium/low). Four matched communities.

Participants

In the main study communities, 94 tobacco retail outlets. All Secondary 2 (aged 13 years) and Secondary 4 (aged 15 years) pupils in 2013 and 2014 together with all Secondary 1 to Secondary 6 (aged 12–17 years) pupils in 2015–17. This included 6612 pupils who completed 14,344 questionnaires over 5 years. Three hundred and eighty-two participants in 80 focus groups who were recruited from Secondary 2 and Secondary 4 in 2013–17. In matched communities, 24 retail panel members in 2013–17.

Main outcome measures

Tobacco product and tobacco storage visibility, density of retail outlets (the number of retailers in a pre-defined area such as a residential neighbourhood), tobacco product exposure, brand awareness, perceived accessibility of tobacco, pro-smoking attitudes, pro-smoking norms, smoking susceptibility and smoking initiation.

Data platform and methods

The study had four components – a mapping and spatial analysis of retail outlets; a tobacco marketing audit, including retail panel interviews in matched communities; school surveys; and focus group discussions with secondary school pupils.

Limitations

The study was based on a small number of communities and did not include communities in remote areas.

Results

Compliance with the point-of-sale legislation in Scotland was high. This led to a large reduction in the visibility of tobacco products in retail outlets. However, when the results were stratified by socioeconomic status, declines in retailer density, weighted by total product visibility, were restricted to the least disadvantaged tertile of participants. Nevertheless, the implementation of the legislation was associated with a reduction in risk of both smoking susceptibility and smoking initiation in young people, as well as a reduction in the perceived accessibility of tobacco and in pro-smoking attitudes after both the partial and the comprehensive bans were introduced.

Conclusions

The Scottish point-of-sale legislation has been successful in reducing the overall visibility of tobacco products and is associated with improvements in attitudinal and behavioural outcomes in young people. However, cues that tobacco is for sale are still highly visible, particularly in retail outlets in areas of deprivation. In addition, the increase in retailer density that was observed after 2015 increased inequalities in product visibility. There was also evidence that the emergence of e-cigarettes may have disrupted the full impact of the legislation.

Future work

Our research indicates that further research is needed to examine the longitudinal relationships between tobacco outlet availability and product visibility inequalities; and the impact of e-cigarettes and standardised packaging on smoking initiation and prevalence.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 8, No. 1. See the NIHR Journals Library website for further project information.

E-cigarette use and onset of first cigarette smoking among adolescents: An empirical test of the 'common liability' theory

Background: E-cigarettes have become the most commonly used tobacco products among youth in the United States (US) recently. It is not clear whether there is a causal relationship between e-cigarette use and the onset of cigarette smoking. The "common liability" theory postulates that the association between e-cigarette use and cigarette smoking can be attributed to a common risk construct of using tobacco products. This study aims to investigate the relationship between ever e-cigarette use and cigarette smoking onset in the US using a structural equation modeling approach guided by the "common liability" theory. Methods: The study population is non-institutionalized civilian adolescents living in the US, sampled in the longitudinal Population Assessment of Tobacco and Health study. Information about tobacco product use was obtained via confidential self-report. A structural equation modeling approach was used to estimate the relationship between e-cigarette use at wave 1 and the onset of cigarette smoking at wave 2 after controlling for a latent construct representing a "common liability to use tobacco products." Results:  After controlling for a latent construct representing a "common liability to use tobacco products", ever e-cigarette use does not predict the onset of cigarette smoking (β=0.13, 95% CI= -0.07, 0.32, p=0.204). The latent "common liability to use tobacco products" is a robust predictor for the onset of cigarette smoking (β=0.38; 95% CI=0.07, 0.69; p=0.015). Conclusions: Findings from this study provide supportive evidence for the 'common liability' underlying observed associations between e-cigarette use and smoking onset.

E-cigarette use and onset of first cigarette smoking among adolescents: An empirical test of the 'common liability' theory

Background: E-cigarettes have become the most commonly used tobacco products among youth in the United States (US) recently. It is not clear whether there is a causal relationship between e-cigarette use and the onset of cigarette smoking. The "common liability" theory postulates that the association between e-cigarette use and cigarette smoking can be attributed to a common risk construct of using tobacco products. This study aims to investigate the relationship between ever e-cigarette use and cigarette smoking onset in the US using a structural equation modeling approach guided by the "common liability" theory. Methods: The study population is non-institutionalized civilian adolescents living in the US, sampled in the longitudinal Population Assessment of Tobacco and Health study. Information about tobacco product use was obtained via confidential self-report. A structural equation modeling approach was used to estimate the relationship between e-cigarette use at wave 1 and the onset of cigarette smoking at wave 2 after controlling for a latent construct representing a "common liability to use tobacco products." Results:  After controlling for a latent construct representing a "common liability to use tobacco products", ever e-cigarette use does not predict the onset of cigarette smoking (β=0.13, 95% CI= -0.07, 0.32, p=0.204). The latent "common liability to use tobacco products" is a robust predictor for the onset of cigarette smoking (β=0.38; 95% CI=0.07, 0.69; p=0.015). Conclusions: Findings from this study provide supportive evidence for the 'common liability' underlying observed associations between e-cigarette use and smoking onset.

E-cigarette use and onset of first cigarette smoking among adolescents: An empirical test of the 'common liability' theory

Background: E-cigarettes have become the most commonly used tobacco products among youth in the United States (US) recently. It is not clear whether there is a causal relationship between e-cigarette use and the onset of cigarette smoking. The "common liability" theory postulates that the association between e-cigarette use and cigarette smoking can be attributed to a common risk construct of using tobacco products. This study aims to investigate the relationship between ever e-cigarette use and cigarette smoking onset in the US using a structural equation modeling approach guided by the "common liability" theory. Methods: The study population is non-institutionalized civilian adolescents living in the US, sampled in the longitudinal Population Assessment of Tobacco and Health study. Information about tobacco product use was obtained via confidential self-report. A structural equation modeling approach was used to estimate the relationship between e-cigarette use at wave 1 and the onset of cigarette smoking at wave 2 after controlling for a latent construct representing a "common liability to use tobacco products." Results:  After controlling for a latent construct representing a "common liability to use tobacco products", ever e-cigarette use does not predict the onset of cigarette smoking (β=0.10, 95% CI= -0.09, 0.29, p=0.299). The latent "common liability to use tobacco products" is a robust predictor for the onset of cigarette smoking (β=0.42; 95% CI=0.08, 0.76; p=0.015). Conclusions: Findings from this study provide supportive evidence for the 'common liability' underlying observed associations between e-cigarette use and smoking onset.

Motivations for using electronic cigarettes in young adults: A systematic review

Background: The most common reasons why adults use e-cigarettes are to stop or reduce tobacco smoking. However, it is unclear if this reason is evenly distributed between young and older adults. Objectives: describe the motivations for e-cigarette use amongst young adults aged 18-25 and compare the reasons for using e-cigarettes of people who currently or formerly used tobacco products to those who had never smoked tobacco prior e-cigarette use. Methods: PubMed^®, Scopus^®, Cochrane Library^®, SocINDEX^®, PsycARTICLES^®, Psychology and Behavioral Sciences Collection^® and PsycINFO^® databases were used. English written articles were screened up to March 2018. Depending on study design, quality was assessed using The STROBE or RATS checklists. Results: Six articles were included in the review, all with a moderate quality of evidence. Independently of smoking status, curiosity was the most frequently reported reason for initiating the use of e-cigarettes in young adults. Reasons for continuing to use e-cigarettes were various. The continued use of e-cigarettes could be either a means to replicate smoking habits, or a way for a different and personalized use of nicotine by inhalation. Conclusions: Reasons for using e-cigarettes in young adults are varied and are not limited to stopping smoking.

Newer Forms of Tobacco Products: Characteristics of Poly Users Among Adults Living in Colorado-A Secondary Data Analysis of the Attitudes and Behaviors Survey on Health 2015

Aims:

Data from The Attitudes and Behaviors Survey (TABS) conducted in 2015 were used to investigate the prevalence of different forms of tobacco use and marijuana use among adults in Colorado.

Methods:

A secondary analysis of TABS on health data was conducted. A representative sample of 8616 adults 18 years and older participated in the survey, with sample weights used to adjust for oversampling.

Results:

Lifetime prevalence of cigarette-only use was 25.8%, compared with 10.6% for hookah use, 7.0% for both hookah and cigarettes, 12.6% for anything except cigarettes, and 43.0% for marijuana. The typical hookah user was a single/living alone (15.9%), English-speaking (11.6%), male (16.7%), age < 30 years (24.2%), with some college education (13.0%), and income less than 35 000 per year (14.3%). Hookah users, whether or not they also used cigarettes, were similar to those who used any other noncigarette tobacco products. The typical marijuana user was a single/living alone (50.2%), white (46.0%), English-speaking (46.7%), male (48.5%), age < 30 years (50.1%), with a graduate degree (40.8%) and salary of at least 50 000 per year (43.4%).

Implications:

In Colorado, in 2015, cigarette use was still highest among all forms of tobacco, but the use of other tobacco products such as vaping and hookah is on the rise, especially among young adults. Marijuana and hookah users were demographically similar to each other, and different from the typical cigarette user. These results indicate the need for further study of alternative tobacco product use, especially among young adults.

Impact of snus use in teenage boys on tobacco use in young adulthood; a cohort from the HUNT Study Norway

Background

As smoking rates decreased, the use of Swedish snus (smokeless tobacco) concordantly increased in Norway. The role of snus as possible contributor to the reduction of smoking has been widely discussed. Our aim was to quantitate transitions in snus use, smoking and dual use of snus and cigarettes in a young male population.

Methods

This prospective cohort study includes 1346 boys participating in the Nord-Trøndelag Health Study in Young-HUNT1 1995–97, age 13–19 and in HUNT3 2006–08, age 23–30. Participants reported on tobacco use at both points of time. Models with binominal regression were applied to examine relative risks (RRs), of adolescent ever snus users, dual users or smokers (reference: never tobacco use), to be current snus only users, smokers (including dual users), or tobacco free in adulthood.

Results

Current tobacco use in this male cohort increased from 27% in adolescence to 49% in adulthood, increasing more for snus only use and dual use than for smoking only.

The adjusted RR (95% CI) of becoming a smoker as young adult, was 2.2 (CI 1.7–2.7) for adolescent snus users, 3.6 (CI 3.0–4.3) for adolescent dual users, and 2.7 (CI 2.2–3.3) for adolescent smokers. RR to become snus only users as adults was 3.1 (2.5–3.9) for adolescent dual users, 2.8 (2.2–3.4) for adolescent snus users and 1.5 (1.0–2.2) for adolescent smokers. The adjusted RR for the transition from adolescent tobacco use to no tobacco use in adulthood was similar for snus users and smokers with RR 0.5 (CI 0.4–0.7), but considerably lower for dual users with RR 0.2 (CI 0.2–0.3).

Conclusions

The use of snus, with or without concurrent smoking, carried a high risk of adult smoking as well as adult snus only use. Dual use seemed to promote the opportunity to become snus only users in adulthood, but made it also more difficult to quit. The benefit of snus use for harm reduction is not evident in our cohort, as the combination of smoking and dual use resulted in high smoking rates among the young adults.

E-Cigarettes and the Use of Conventional Cigarettes

BACKGROUND

In 2015, 12.1% of 12- to 17-year-olds in Germany had reportedly already tried e-cigarette smoking at least once. We carried out a study of the "gateway" hypothesis, according to which the use of e-cigarettes can motivate adolescents to start smoking conventional cigarettes.

METHODS

During the 2015/2016 school year, 2186 tenth-graders in the German states of Lower Saxony and Schleswig-Holstein who had never smoked conventional cigarettes before took part in a survey over a 6-month period (mean age 15.5 years, standard deviation 0.65; 53.6% female).

RESULTS

14.3% of the survey population (313 adolescents) said at the start of the survey period that they had already tried e-cigarettes at least once. By the end of the survey period, 12.3% (268) of those who had never smoked before had begun to experiment with conventional cigarettes. The risk of beginning such experimentation was 2.2 times higher among e-cigarette users. This association remained (relative risk = 2.18 [1.65; 2.83]) after statistical control for age, sex, state, immigrant background, type of school, socioeconomic status, various personality traits (sensation-seeking, impulsivity, anxiety, hopelessness, extraversion, agreeableness, conscientiousness, neuroticism, openness), and the use of alcohol, cannabis, and other illicit drugs. Further analysis revealed that the association between the use of e-cigarettes and the onset of conventional cigarette smoking was stronger among adolescents with low sensation-seeking scores and without any experience of alcohol intoxication.

CONCLUSION

Among adolescents who have never smoked, experimentation with conventional cigarettes is more common in those who have used e-cigarettes. This effect seems to be stronger among adolescents who, in general, have a lower risk of starting to smoke. The 6-month observation period of this study is too short to allow any inference regarding a connection between e-cigarette use and the development of tobacco dependence.

Cigarettes, E-cigarettes, and Adolescents' Oral Health: Findings from the Population Assessment of Tobacco and Health (PATH) Study

INTRODUCTION

Adolescents are a population group that actively uses tobacco products; however, limited reports are available on the effects of tobacco products on adolescents' oral health.

OBJECTIVES

This study investigated associations between self-reported use of cigarettes and e-cigarettes on the oral health status of a representative sample of US adolescents.

METHODS

Data came from 13,650 adolescents aged 12 to 17 y who participated in the 2013-2014 wave of the Population Assessment of Tobacco and Health study. Participants self-reported current use (i.e., past 30 d) and ever use of cigarettes and e-cigarettes, as well as past-year diagnoses with dental problems by a doctor, dentist, or other health professional (self-reported by parent or emancipated youth). Survey-adjusted logistic regression was used to estimate prevalence odds ratios (PORs) and 95% CIs.

RESULTS

The proportion of adolescents who self-reported current use of only cigarettes was 3.2%, while 1.7% reported current use of only e-cigarettes. Similarly, 1.4% reported current use of both cigarettes and e-cigarettes, while 7.1% reported ever use of both. About 22% self-reported a provider diagnosis with dental problems in the past year. The covariate-adjusted associations between current cigarette and e-cigarette use on self-reported provider-diagnosed dental problems in the past year were, respectively, POR = 1.50 (95% CI, 1.18 to 1.90) and POR = 1.11 (95% CI, 0.79 to 1.55), while self-reported current use of both was associated with POR = 1.72 (95% CI, 1.24 to 2.38). Ever use of cigarettes and e-cigarettes was likewise associated with increased prevalence odds of self-reported past-year diagnosis with dental problems, although to a lesser magnitude.

CONCLUSION

Findings suggest that dual use of e-cigarettes and conventional cigarettes is associated with poor oral health outcomes among adolescents. However, studies of a longitudinal nature are needed to confirm these findings.

KNOWLEDGE TRANSFER STATEMENT

The results of this study are relevant to public health and oral health practitioners seeking to intervene during developmental periods in which adolescents may have access to tobacco products in the home and in social settings.

E-cigarette use is associated with susceptibility to tobacco use among Australian young adults

BACKGROUND

Calls have been made to relax current Australian regulations related to e-cigarettes to increase the accessibility of the devices for smoking cessation purposes. However, e-cigarettes have been found to increase risk of initiation of conventional cigarette smoking, especially among young adults. To assist in guiding the development of policy in Australia, the present study examined whether e-cigarette use among Australian young adults who have never smoked a tobacco cigarette is associated with susceptibility to future tobacco cigarette use.

METHOD

An online web panel provider recruited 519 never smokers aged 18-25 years (55% female; average age = 21.21 years, SD = 2.32). Respondents completed an online survey that assessed their curiosity about tobacco smoking, willingness and intentions to smoke, and a number of individual and social factors. Cross-sectional regression analyses were conducted to assess the association between e-cigarette use and susceptibility to tobacco cigarette use while controlling for multiple covariates.

RESULTS

Curiosity about tobacco smoking, willingness to smoke, and intentions to smoke were significantly higher among users of e-cigarettes than never users. The relationship between e-cigarette use and susceptibility to future tobacco cigarette use remained significant after controlling for numerous covariates.

CONCLUSION

E-cigarette use, even just one or two puffs, has the potential to increase susceptibility to tobacco cigarette use among Australian young adults. Findings suggest that increasing the availability of e-cigarettes by relaxing current strict regulations surrounding their sale may have unintended consequences.

Do population trends in adolescent electronic cigarette use coincide with changes in prevalence of cigarette smoking?

Adolescents who initiate electronic cigarette (EC) use without having ever used tobacco are more likely than those that have not initiated EC use to try cigarette smoking over time. However, whether rates of EC use coincide with cigarette smoking rates at the population level remains unknown. This study aimed to compare trends in ever, current, and daily use of EC and cigarette smoking among adolescents in Iceland from 2015 to 2018. We analyzed four waves of pooled cross-sectional population-based school survey data with students enrolled in the 8th, 9th and 10th grades in the national Icelandic school system (n = 42,440, boys = 50.1%). Response rates ranged between 83.3% and 86.0%. Findings for 8th, 9th, and 10th grade students, and the combined sample, revealed a consistent pattern: prevalence of cigarette smoking either remained unchanged or decreased minimally over the study period. In the combined sample rates of ever smoking remained between 9 and 10% during the entire study period, whereas the prevalence of daily cigarette smoking was around 1%. The use of EC increased 2- to 3-fold in all age groups. Ever use increased from 12% to roughly 30% in the combined group and daily use increased from about 2% to 6% during the same period. We conclude that the prevalence of adolescent cigarette smoking in Iceland remained mostly unchanged between the years 2015 and 2018, whereas EC use increased exponentially during the same period. The prevalence of EC use now far outweighs cigarette smoking in 8th–10th grade youth in Iceland.

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Trends in adolescent e-cigarette use and cigarette smoking, 2015–2018, is reported.

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Cigarette smoking remained mostly unchanged during the study period.

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E-cigarette use increased exponentially in all age groups during the study period.

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E-cigarette use now far outweighs cigarette smoking among youth in Iceland.

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Over 40% of 10th grade students have tried e-cigarettes and 10% are daily users.

Survey of the effect of viewing an online e-cigarette advertisement on attitudes towards cigarette and e-cigarette use in adults located in the UK and USA: a cross-sectional study

OBJECTIVES

This study explored the potential for e-cigarette advertisements to (1) enhance attitudes towards cigarettes and/or (2) reduce barriers to e-cigarettes uptake. The study tested whether exposure to an online electronic cigarette advertisement changed attitudes towards cigarettes and e-cigarettes in smokers, non-smokers, e-cigarette users and dual users (smokers who also use e-cigarettes).

DESIGN

Cross-sectional study SETTING: Online survey PARTICIPANTS: Adults (n=964) aged 18 to 65 years old (M=36 years, SD=11.6) from the UK and USA. Participants were grouped into current non-smokers, e-cigarette users, dual users and smokers.

INTERVENTIONS

Participants viewed 1 of 15 randomly assigned online e-cigarette advertisements.

PRIMARY MEASURES

Three single seven-point Likert scales measuring health, desirability, social acceptability were completed pre and post advertisement exposure.

RESULTS

Post exposure all smoking groups showed a decrease or no change in how socially acceptable or desirable they rated cigarettes. Paradoxically, dual users rated cigarettes as being significantly healthier after viewing the advertisement (p=0.01) while all other smoking group ratings remained the same. There was an increase or no change in how all smoking groups perceived the healthiness and desirability of e-cigarettes CONCLUSIONS: We observed no evidence that exposure to an e-cigarette advertisement renormalises or encourages smoking in smokers, non-smokers or e-cigarette users. However, there is some indication that viewing an e-cigarette advertisement may increase duals users' perceptions of the health of smoking.

[Relationship between vaping and smoking among 15-year-olds in high school. Results of a descriptive cross-sectional and monocentric observational study conducted in the metropolitan area of Saint-Étienne]

INTRODUCTION

The initiation of smoking among adolescents by vaping is a subject of controversy. This study focuses on the prevalence of electronic cigarette use among teenagers and its connection with the consumption of tobacco.

METHODS

A cross-sectional and monocentric study was conducted in the spring of 2018 and included 1435 students (15-16years old) from the metropolitan area of Saint-Étienne in France.

RESULTS

Nearly half of the adolescents experimented with e-cigarettes (50.30%) or tobacco (50.40%). Nearly a quarter are vapers (23.60%) or smokers (28.20%), with low daily use (3.65% for vaping and 9.40% for smoking). In regard to the link between smoking and vaping, 64.85% of adolescents are "non-smokers and non-vapers", 17.60% "smokers and vapers", 11.25% "smokers and non-vapers", and 6.30% "non-smokers and vapers".

DISCUSSION

The portrait-types of the vaper and the smoker are similar: boy rather than girl, educated in private school rather than public, and enrolled in a vocational rather than a general educational course. On one hand, the use of electronic cigarettes in non-smoking adolescents does not appear to be a major mode of entry into smoking or nicotine addiction. On the other hand, the use of electronic cigarettes among adolescent's smokers seems to have a beneficial effect on their smoking habit (stopping or reducing the consumption of tobacco).

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.

E-cigarettes, alcohol use, and mental health: Use and perceptions of e-cigarettes among college students, by alcohol use and mental health status

INTRODUCTION

Electronic cigarettes (e-cigarettes) are popular among college students, who display risky alcohol use patterns. However, little is known about patterns of co-use of e-cigarettes and alcohol. Further, relationships between e-cigarette use and mental illness among college students are unclear.

METHODS

College student participants (N = 631) at a northeastern U.S. university were invited via email to participate in a survey about e-cigarettes and alcohol use. Mental health was self-reported diagnosis of psychiatric (depression, bipolar disorder, schizophrenia, PTSD, anxiety disorder, personality disorder), and substance (alcohol and other drug) use disorders. Current use of e-cigarette, combustible cigarette, and other tobacco products were assessed via self-reported past 30-day use frequency. Alcohol consumption was assessed via number of self-reported standard alcoholic beverages consumed during a typical drinking episode. Participants also reported regarding co-use of alcohol, e-cigarettes and/or combustible cigarettes. Participants were categorized as non-drinkers, moderate drinkers or binge drinkers, and associations between e-cigarette use, drinking patterns and mental health diagnoses were examined.

RESULTS

E-cigarette use was associated with drinking alcohol χ2 = 18.62, p < .001, and binge drinking (vs. moderate drinking) χ2 = 12.20, p < .001. Students who had tried e-cigarettes reported drinking more alcohol per episode (χ2 = 15.94, p < .001). E-cigarette use was more prevalent among those with psychiatric and substance use disorders χ2 = 11.65, p < .001.

CONCLUSIONS

Drinking college students (especially binge drinkers) and those with mental illness may have heightened risks for e-cigarette use. More research is needed to elucidate relationships between risky alcohol and/or nicotine use and mental illness, and to guide appropriate prevention and intervention efforts for vulnerable college students.

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.