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

Usage, knowledge and attitudes towards electronic cigarettes use among nursing students in Croatia: a cross-sectional study

BACKGROUND

Evidence shows harmful effects of e-cigarettes on health. There is limited data on the use of e-cigarettes among nursing students. This study aimed to investigate the usage, knowledge, and attitudes towards e-cigarettes among nursing students in Croatia, as well as their views on the role of nurses in counseling patients and assisting with smoking cessation.

METHODS

This cross-sectional study was conducted via an online questionnaire among nursing students at 10 universities in Croatia in March/April 2024. Students were asked questions about socio-demographics, knowledge and attitudes towards e-cigarettes and their views on the role of nurses in counseling patients and assisting with smoking cessation.

RESULTS

The study included 1,039 participants; 89% were women, 43% were smokers; 53% used e-cigarettes and 76% used them for recreational purposes. 21% of participants agreed that e-cigarettes are an effective method for quitting smoking. More than half indicated that e-cigarettes could encourage non-smokers to start smoking. The majority (60%) reported that they had never received education on smoking cessation at university. Furthermore, 66% stated that they did not feel confident advising smokers about e-cigarettes. The majority (70%) considered physicians to be the most knowledgeable health experts to advise and educate users of e-cigarettes. There were no significant differences in attitudes between smokers and non-smokers on the use of e-cigarettes. Participants demonstrated insufficient knowledge about e-cigarettes. Non-smokers had more positive attitudes towards the role of nurses in combating smoking compared to smokers. Participants who had received education on smoking cessation were more willing to advise smokers and had clearer views on the risks and the importance of the nurse's role in the quitting process compared to those who had not received such education. Smoking status and age were significant predictors of counseling confidence.

CONCLUSION

The study found a high prevalence of smoking and e-cigarette use among Croatian nursing students, along with limited knowledge and generally negative attitudes towards e-cigarettes. It highlighted gaps in education regarding the health risks of e-cigarettes and the lack of practical skills needed to help smokers quit, suggesting that nursing programs should update their curricula to better prepare students in these areas.

Factors Associated With the Changes in Smoking and Electronic cigarette use in Adolescents During the COVID-19 Pandemic: A Longitudinal Analysis

PURPOSE

Explore the factors associated with the changes in smoking and electronic cigarette (e-cigarette) use and susceptibility among adolescents during the COVID-19 pandemic.

METHODS

We surveyed a cohort of students (7th-12th grade) from private schools in Guatemala. Baseline (May-September 2019) was conducted in-person and follow-up (June-November 2020) online during the lockdown. Separate Generalized Estimating Equations logistic models regressed current smoking (n = 3,729), current e-cigarette use (n = 3,729), smoking susceptibility among never-smokers (n = 2,596), and susceptibility to e-cigarette use among never-users (n = 1,597) on online ad exposure, visiting stores, social network smoking/e-cigarette use, substance use (alcohol, marihuana, and cigarette or e-cigarette), perceived harm of using cigarettes/e-cigarettes, sociodemographic characteristics, and survey wave. Interactions were assessed between time and ad exposures, friends smoking and e-cigarette use.

RESULTS

Frequency of store visits, exposure to online ads, and the use of cigarette and e-cigarette lowered at follow-up. Online e-cigarette ads, having family and friends who smoke, and current e-cigarette use increased the likelihood of being a current smoker. Frequent exposure to online e-cigarette ads, having family who use e-cigarettes, and being a current smoker were associated with higher likelihood of current e-cigarette use. Exposure to either online ads or having friends that smoke or use e-cigarettes, increased susceptibility to using either product. Interaction results showed that high exposure to online e-cigarette ads overtime increased the susceptibility to use e-cigarettes.

DISCUSSION

Exposure to online ads and friends and family cigarette and e-cigarette use increased adolescent consumption and susceptibility during the pandemic.

Parent's awareness of, and influence on, their 14-17-year-old child's vaping and smoking behaviours; an analysis of 3242 parent-child pairs in Australia

BACKGROUND

Vaping by young people in Australia is a rapidly emerging public health issue. Evidence shows that parental behaviours and attitudes can play a key role in influencing adolescent behaviours. Considering the health harms of vaping and evidence that it can be a gateway to tobacco smoking for never-smokers, it is important to understand whether parents' smoking and vaping behaviours influence their teenage children's smoking and vaping behaviours.

METHODS

Online cross-sectional surveys as part of the Generation Vape study, conducted in Australia in 2021/2022, were used to assess parents' influence on, and awareness of, one of their 14-17-year-old child's vaping and smoking behaviours. Participants were 3242 parents and 3242 14-17-year-old teenage children.

RESULTS

The risk of vaping and smoking uptake among 14-17-year-old teenagers was 42% (p = 0.003) and 97% (p < 0.001) higher, respectively, if their parent was an ever-vaper. The risk of vaping and smoking uptake among teenagers was 81% (p < 0.001) and 159% (p < 0.001) higher, respectively, if their parent was an ever-smoker. Parents of teenagers who have not vaped were considerably better at correctly predicting this (97% correct) than parents of teenagers who have vaped (70% correct). Compared to parents, teenagers tended to have less agreement with statements suggesting vaping is unsafe or harmful, and more agreement with statements suggesting vaping is relatively safe.

CONCLUSIONS

Parental smoking and vaping behaviours are associated with those of their children. Hence, it is important that both tobacco and vaping control policies and interventions are designed to influence behaviours of all demographics, consistent with the evidence.

Vaping harms awareness messaging: exploring young South Australians' responses to vaping prevention campaign materials

Nicotine vaping products (NVPs) pose health risks associated with nicotine dependence and increased likelihood of tobacco consumption. Despite having a secondary role in smoking cessation, recreational NVP use is increasing among younger people. Vaping prevention campaigns aim to influence views on the health risks of vaping. This study examined perceptions of Australian and international vaping prevention campaigns among 27 young South Australians aged 16-26 years who do and do not use NVPs, to inform targeting and framing of vaping risk messaging. Participants viewed example materials from three vaping prevention campaigns: 'Epidemic', 'Do you know what you're vaping' and 'Unveil what you inhale'. Focus groups and interviews assessed whether materials were easily understood, appropriate, relevant, credible and effective in health communication. Participants indicated that all campaigns would influence their thoughts and actions related to vaping. The 'Do you know what you're vaping' campaign prompted thoughts about uncertainty about individual health risks, though participants did not indicate that this was enough to motivate vaping cessation. Participants considered the 'Unveil' campaign effective, with those who did not vape indicating they would click through to access resources, and those who did vape responding well to the 'challenge' aspect of the messaging. The 'Epidemic' campaign fear appeal did not clearly prompt change in vaping views or behaviours. Campaigns using a challenge approach may generate conversation about vaping harms, while fear appeals can be dismissed by younger audiences. Evidence-based short messages and the presentation of multiple versions of content were considered effective approaches.

Systematic Review and Critical Analysis of Longitudinal Studies Assessing Effect of E-Cigarettes on Cigarette Initiation among Adolescent Never-Smokers

Prospective longitudinal studies mainly conclude on a causal role of e-cigarettes in the initiation of cigarettes in flagrant contradiction with conclusions drawn from epidemiology and other studies showing a sharp decline in cigarette use in parallel with the spread of e-cigarette use. This systematic review explores the reasons for this discrepancy.

METHODS

Among 84 publications on e-cigarette/cigarette association in adolescents identified in the Medline database from 2011 to 2022, 23 concern 22 never-smoker longitudinal sub-cohorts.

RESULTS

A link between e-cigarette experimentation at T1 and cigarette initiation at T2 is reported in sub-cohort analyses of never-smokers (AOR: 1.41 to 8.30). However, studies exclude 64.3% of T1 e-cigarette experimenters (because of dual-use) and 74.1% of T2 cigarette experimenters. With this study design, e-cigarettes contribute only to 5.3% of T2 cigarette experimentation, casting major doubt on the external validity of results and authors' conclusions that e-cigarettes have a significant effect on the initiation of cigarettes (Gateway effect) at the population level. This sub-cohort design prohibits highlighting any Diversion effect, which is the most likely mechanism accounting for the competition between these two products.

CONCLUSIONS

While nicotine abstinence remains the best medical option, over-regulation of e-cigarettes because of misinterpretation of longitudinal study results may be detrimental to public health and tobacco control.

Exploring the gateway hypothesis of e-cigarettes and tobacco: a prospective replication study among adolescents in the Netherlands and Flanders

BACKGROUND

Studies demonstrated that adolescent e-cigarette use is associated with subsequent tobacco smoking, commonly referred to as the gateway effect. However, most studies only investigated gateways from e-cigarettes to tobacco smoking. This study replicates a cornerstone study revealing a positive association between both adolescent e-cigarette use and subsequent tobacco use; and tobacco and subsequent e-cigarette use in the Netherlands and Flanders.

DESIGN

The longitudinal design included baseline (n=2839) and 6-month (n=1276) and 12-month (n=1025) follow-up surveys among a school-based cohort (mean age: 13.62). Ten high schools were recruited as a convenience sample. The analyses involved (1) associations of baseline e-cigarette use and subsequent tobacco smoking among never smokers; (2) associations of e-cigarette use frequency at baseline and tobacco smoking frequency at follow-up; and (3) the association of baseline tobacco smoking and subsequent e-cigarette use among non-users of e-cigarettes.

FINDINGS

Consistent with prior findings, baseline e-cigarette use was associated with higher odds of tobacco smoking at 6-month (OR=1.89; 95% CI 1.05 to 3.37) and 12-month (OR=5.63; 95% CI 3.04 to 10.42) follow-ups. More frequent use of e-cigarettes at baseline was associated with more frequent smoking at follow-ups. Baseline tobacco smoking was associated with subsequent e-cigarette use (OR=3.10; 95% CI 1.58 to 6.06 at both follow-ups).

CONCLUSION

Our study replicated the positive relation between e-cigarette use and tobacco smoking in both directions for adolescents. This may mean that the gateway works in two directions, that e-cigarette and tobacco use share common risk factors, or that both mechanisms apply.

Association of Electronic Cigarette Use by US Adolescents With Subsequent Persistent Cigarette Smoking

Importance

Many studies have reported a positive association of youth electronic cigarette (e-cigarette) use with subsequent cigarette smoking initiation, but it remains unclear whether e-cigarette use is associated with continued cigarette smoking after initiation.

Objective

To assess the association of youth baseline e-cigarette use with their continued cigarette smoking 2 years after initiation.

Design, Setting, and Participants

The Population Assessment of Tobacco and Health (PATH) Study is a national longitudinal cohort study. This sample consisted of youth who participated in waves 3, 4, and 5 of the study (wave 3 was from October 2015 to October 2016, wave 4 was from December 2016 to January 2018, and wave 5 was from December 2018 to November 2019) and had never used cigarettes (cigarette-naive) by wave 3. The current analysis used multivariable logistic regressions in August 2022 to assess the association between e-cigarette use among cigarette-naive adolescents aged 12 to 17 years in 2015 and 2016 and subsequent continued cigarette smoking. PATH uses audio computer-assisted self-interviewing and computer-assisted personal interviewing to collect data.

Exposures

Ever and current (past 30-day) use of e-cigarettes in wave 3.

Main Outcomes and Measures

Continued cigarette smoking in wave 5 after initiating smoking in wave 4.

Results

The current sample included 8671 adolescents who were cigarette naive in wave 3 and also participated in waves 4 and 5; 4823 of the participants (55.4%) were aged 12 to 14 years, 4454 (51.1%) were male, and 3763 (51.0%) were non-Hispanic White. Overall, regardless of e-cigarette use, few adolescents (362 adolescents [4.1%]) initiated cigarette smoking at wave 4, and even fewer (218 participants [2.5%]) continued smoking at wave 5. Controlling for multiple covariates, the adjusted odds ratio of baseline ever e-cigarette use, compared with never e-cigarette use, was 1.81 (95% CI, 1.03 to 3.18) for continued smoking measured as past 30-day smoking at wave 5. However, the adjusted risk difference (aRD) was small and not significant. The aRD was 0.88 percentage point (95% CI, -0.13 to 1.89 percentage points) for continued smoking, with the absolute risk being 1.19% (95% CI, 0.79% to 1.59%) for never e-cigarette users and 2.07% (95% CI, 1.01% to 3.13%) for ever e-cigarette users. Similar results were found using an alternative measure of continued smoking (lifetime ≥100 cigarettes and current smoking at wave 5) and using baseline current e-cigarette use as the exposure measure.

Conclusions and Relevance

In this cohort study, absolute and relative measures of risks yielded findings suggesting very different interpretations of the association. Although there were statistically significant odds ratios of continued smoking comparing baseline e-cigarette users with nonusers, the minor risk differences between them, along with the small absolute risks, suggest that few adolescents are likely to continue smoking after initiation regardless of baseline e-cigarette use.

Stealth vaping and associated attitudes, perceptions, and control beliefs among US college students across four tobacco-free campuses

OBJECTIVES

Stealth vaping gained popularity among college students in recent years. It may undermine the benefits introduced by tobacco-free policies. Yet, no studies have investigated attitude and belief factors associated with stealth vaping. The objective of the study was to explore the relationship between attitudes toward on-campus tobacco regulations, normative perceptions of stealth vaping behaviors, and control beliefs with on-campus stealth vaping among U.S. college students.

METHODS

Participants from four large, public universities with policies prohibiting use of all forms of tobacco (including e-cigarettes) on campus (N = 863) completed an online survey in Fall 2020. On-campus stealth vaping behavior was captured by past 30-day stealth vaping status and frequency. Hurdle models with logistic and negative binomial regressions were conducted, where stealth vaping status was treated as a binary variable based on the non-zero and zero frequency, and stealth vaping frequency was treated as a count variable. Multiple imputation by chained equations was employed to handle the missing data.

RESULTS

Participants with more positive attitudes toward regulating on-campus tobacco use were less likely to practice stealth vaping on campus (OR = 1.16, p < 0.01 [predicting zero]). Those with higher perceptions of stealth vaping among other students were more likely to stealth vape more frequently (IRR = 1.03, p < 0.01).

CONCLUSION

Our results highlight the need for interventions to address students' attitudes and normative beliefs about stealth vaping. Efforts are needed to educate college students about the risk of e-cigarettes and to enhance enforcement of campus tobacco-free policies.

Impact of Electronic Cigarette Vaping on Cerebral Ischemia: What We Know So Far

Electronic cigarettes (ECs) are battery-powered nicotine delivery devices that have rapidly gained popularity and attention globally. ECs work by heating a liquid to produce an aerosol that usually contains nicotine, flavoring compounds, and other chemicals, which are inhaled during vaping. EC aerosols are depicted to contain a lower number and overall quantity of harmful toxicants than conventional cigarettes (CCs). However, emerging research indicates that EC aerosols contain harmful ingredients including ultrafine particles, volatile organic compounds, and heavy metals. One common ingredient found in both CCs and ECs is nicotine, which has been shown to be both highly addictive and toxic. Particularly relevant to our current review, there is an enormous amount of literature that shows that smoking-derived nicotine exacerbates ischemic brain damage. Therefore, the question arises: will EC use impact the outcome of stroke? ECs are highly popular and relatively new in the market; thus, our understanding about the long-term effects of EC use on brain are lacking. The current review strives to extrapolate the existing understanding of the nicotine-induced effects of conventional smoking on the brain to the possible effects that ECs may have on the brain, which may ultimately have a potential for adverse stroke risk or severity.

Addressing adolescent substance use with a public health prevention framework: the case for harm reduction

Adolescence is a developmental stage defined in part by risk-taking. Risk-taking is critical to normal development and has important benefits including trying new activities and exploring new relationships. Risk-taking is also associated with the initiation of substance use. Because substance use often begins in adolescence, much focus has been on primary prevention with the goal of preventing initial substance use. Secondary or tertiary prevention approaches, such as counselling to eliminate substance use or offering treatment, are common approaches for adolescents with problematic substance use or a substance use disorder. While this is important, for some adolescents, treatment or cessation of use may not be desired. In these cases, Healthcare Practitioners (HCPs) can offer clear advice that incorporates harm reduction. Harm reduction, which is often applied for adults who use substances, reduces the negative impacts associated with drug use without requiring abstinence. Harm reduction is crucial to keeping adolescents safe and healthy and can offer opportunities for future engagement in treatment. The objective of this review is to describe strategies for integrating harm reduction principles in clinical settings that are developmentally appropriate. A patient-centered, harm reduction approach can validate perceived benefits of substance use, offer strategies to minimise harm, and advise reduction of use and abstinence.KEY MESSAGES:Substance use often begins in adolescence and traditional approaches are often rooted in prevention framework.Harm reduction should be incorporated for adolescents with problematic substance use or a substance use disorder.This review offers strategies for integration of harm reduction principles tailored towards adolescents.

E-cigarettes and Vaping: A Smoking Cessation Method or Another Smoking Innovation?

The prevalence of using e-cigarettes (vaping) has risen rapidly since its introduction in 2007, mostly among male youth. Although research on the health risks of e-cigarettes is still limited, there is growing evidence of debilitating pulmonary conditions and general immune weakness from e-cigarettes, leading to various infections. Moreover, there are concerns that vaping could be used as a new model of cannabis consumption, increasing cannabis addiction among adolescents. With well-known health risks from traditional smoking, e-cigarettes are viewed as a safe way of smoking, appealing more to youth. Additionally, extensive e-cigarette marketing boosted by the internet and fame has resulted in worries that e-cigarettes can lead to a renormalization of cigarette smoking and can be used as a new method to consume vaporized drugs. Although the concern that e-cigarettes are as harmful as traditional smoking has been raised, youth and most healthcare providers remain relatively unaware. Therefore, this review explored the association between e-cigarettes and traditional smoking. With the introduction of e-cigarettes in the last two decades, the topic is still new and less studied. Therefore, this review will help us understand the topic to better care for e-cigarette smokers and reduce the increasing public health burden from vaping.

E-cigarettes and their lone constituents induce cardiac arrhythmia and conduction defects in mice

E-cigarette use has surged, but the long-term health effects remain unknown. E-cigarette aerosols containing nicotine and acrolein, a combustion and e-cigarette byproduct, may impair cardiac electrophysiology through autonomic imbalance. Here we show in mouse electrocardiograms that acute inhalation of e-cigarette aerosols disturbs cardiac conduction, in part through parasympathetic modulation. We demonstrate that, similar to acrolein or combustible cigarette smoke, aerosols from e-cigarette solvents (vegetable glycerin and propylene glycol) induce bradycardia, bradyarrhythmias, and elevations in heart rate variability during inhalation exposure, with inverse post-exposure effects. These effects are slighter with tobacco- or menthol-flavored aerosols containing nicotine, and in female mice. Yet, menthol-flavored and PG aerosols also increase ventricular arrhythmias and augment early ventricular repolarization (J amplitude), while menthol uniquely alters atrial and atrioventricular conduction. Exposure to e-cigarette aerosols from vegetable glycerin and its byproduct, acrolein, diminish heart rate and early repolarization. The pro-arrhythmic effects of solvent aerosols on ventricular repolarization and heart rate variability depend partly on parasympathetic modulation, whereas ventricular arrhythmias positively associate with early repolarization dependent on the presence of nicotine. Our study indicates that chemical constituents of e-cigarettes could contribute to cardiac risk by provoking pro-arrhythmic changes and stimulating autonomic reflexes.

Electronic cigarettes versus nicotine-replacement therapy for smoking cessation: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Nicotine-replacement therapy (NRT) and electronic cigarettes (e-cigarettes) have been frequently used for smoking cessation. The aim of this review is to investigate the effectiveness and safety of e-cigarettes versus NRT for smoking cessation.

METHODS

We searched PubMed, EMBASE, the Cochrane Library from inception to 10 October 2021. We included randomized controlled trials (RCTs) comparing e-cigarettes versus NRT for smoking cessation. Two authors independently screened titles, abstracts and full texts for eligibility. Paired authors extracted data, assessed risk of bias, and used GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) to rate the certainty of evidence.

RESULTS

The study included five RCTs with 1748 participants. The meta-analysis suggested the e-cigarettes versus NRT increased the ≥6 months continuous abstinence rate (RR=1.67; 95% CI: 1.21-2.28; 55 more per 1000 participants, low certainty), and 7-day point abstinence rate at ≥6 months follow-up (RR=1.43; 95% CI: 1.19-1.72; 84 more per 1000, low certainty). However, we found no evidence that e-cigarettes versus NRT increased 3-6 months continuous abstinence rate (RR=1.07; 95% CI: 0.73-1.57; 10 more per 1000, very low certainty) and <3 months continuous abstinence rate (RR=1.20; 95% CI: 0.90-1.60; 54 more per 1000, low certainty); similar results were found at <3 months follow-up (RR=1.19; 95% CI: 0.92-1.54; 55 more per 1000, very low certainty) and 3-6 months follow-up in 7-day point abstinence rate (RR=1.01; 95% CI: 0.70-1.44; 2 more per 1000, very low certainty). The adverse events were not significant between e-cigarettes and NRT other than throat irritation (RR=1.27; 95% CI: 1.13-1.42; 118 more per 1000, low certainty).

CONCLUSIONS

E-cigarettes appeared to be superior to NRT in ≥6 months continuous abstinence rate and 7-day point abstinence rate. At short-term duration, we found no evidence that e-cigarettes compared to NRT increased the <6 months continuous abstinence rate and 7-day point abstinence rate.

Impact of vaping on respiratory health

Widespread uptake of vaping has signaled a sea change in the future of nicotine consumption. Vaping has grown in popularity over the past decade, in part propelled by innovations in vape pen design and nicotine flavoring. Teens and young adults have seen the biggest uptake in use of vape pens, which have superseded conventional cigarettes as the preferred modality of nicotine consumption. Relatively little is known, however, about the potential effects of chronic vaping on the respiratory system. Further, the role of vaping as a tool of smoking cessation and tobacco harm reduction remains controversial. The 2019 E-cigarette or Vaping Use-Associated Lung Injury (EVALI) outbreak highlighted the potential harms of vaping, and the consequences of long term use remain unknown. Here, we review the growing body of literature investigating the impacts of vaping on respiratory health. We review the clinical manifestations of vaping related lung injury, including the EVALI outbreak, as well as the effects of chronic vaping on respiratory health and covid-19 outcomes. We conclude that vaping is not without risk, and that further investigation is required to establish clear public policy guidance and regulation.

Perceptions and Use of Electronic Cigarettes Among Young Adults in Vietnam 2020

Electronic cigarette use among adolescents has increased in the past decade. Little is known about the perception and use of e-cigarettes in Vietnam, especially among young people. This study examines the perceptions and use of electronic cigarettes among young adults in Vietnam. The study uses data from a survey of adult tobacco consumption among adults at the provincial level in 2020, which was funded and managed by the Vietnam Tobacco Control Fund-Ministry of Health. Data were collected from 34 provinces and cities throughout Vietnam and managed using REDCap software. The survey engaged 80,166 participants, of which 9478 were young adults aged 15-24 were selected and reported in this paper. The results show that, at the time of the survey, 2.4% of young Vietnamese adults were smoking e-cigarettes. Many survey participants cited more than one reason for smoking e-cigarettes. These reasons included preferring the taste of e-cigarettes (64.0%), disliking the odour of other cigarettes (46.2%), following the example of family members (44.9%), and believing e-cigarettes threatened fewer health risks (39.1%). Almost half of the e-cigarette users wanted to quit (48%). E-cigarette use was associated with males living in urban areas who are aware of the Law on Prevention and Control of Tobacco Harms. The findings of this study provide evidential data that support public health policies aimed at reducing and ceasing e-cigarette use among young people.

E-cigarette Transitions Among US Youth and Adults: Results from the Population Assessment of Tobacco and Health Study (2013-2018)

Currently, the debate surrounding the regulation of e-cigarettes focuses mainly on the size of e-cigarettes' potentially beneficial effects (i.e., adult cessation) versus their unwarranted effects (i.e., initiation among tobacco-naïve adolescents). Therefore, we investigated the relative scale of e-cigarette use transitions in the United States. We reported cross-sectional weighted prevalence estimates of past-month e-cigarette use by ever cigarette use from Waves 1-4 of the Population Assessment of Tobacco and Health study (2013-2018) among youth (12-17 years) and adults (≥ 18 years). We also examined past-month e-cigarette mono and dual transitions related to cigarette smoking and reported the longitudinal weighted prevalence across waves. Among youth new e-cigarette users, the proportion of never-cigarette smokers increased from 24.1 in Wave 1 (n = 418) to 51.4% in Wave 4 (n = 310) (p < 0.0001 for trend). Of youth past-month e-cigarette mono-users in Wave 1 (n = 151), 15.2% transitioned to cigarette mono-use and 8.2% dual-use at Wave 2 or 3 or 4, compared to 60.2% no tobacco use and 16.4% e-cigarette mono-use. Among young adult past-month dual-users (18-24 years; n = 684), 22.6% transitioned to no tobacco use, 60.1% continued cigarette use, 11.4% dual use, and 5.9% e-cigarette mono-use. Among adult dual-users ≥ 25 years old (n = 1560), 13.6% transitioned to no tobacco use, 71.3% cigarette mono-use, 9.0% dual-use, and 6.1% e-cigarette mono-use. Transition to cigarette mono-use and continued dual-use were common among adult past-month e-cigarette users, while e-cigarette initiation was common among youth never-cigarette smokers. These findings contrast with data from other countries showing limited evidence of e-cigarette initiation among youth never cigarette smokers. Both e-cigarette and cigarette use should be addressed in youth and adults, given the potential for dual use in both populations.

Predictors of electronic cigarette use and its association with respiratory health and obesity in young adulthood in Sweden; findings from the population-based birth cohort BAMSE

Despite the growing popularity of electronic cigarettes (e-cigarettes) over the last decade, few epidemiological studies have examined the influence on respiratory health in young adulthood. The aim of this study was to identify factors associated with e-cigarette use in young adulthood in Sweden, and to examine associations between e-cigarette use and lung function, respiratory symptoms, and obesity. This cross-sectional study included 3055 young adults from Sweden and used questionnaire and clinical data obtained at age 22-25 years. The prevalence of current e-cigarette use was 3.9% (n = 120). Few participants reported daily (0.4%) or exclusive (0.8%) use of e-cigarettes. In a multivariable adjusted logistic regression model, e-cigarette use was significantly associated with male gender (OR:3.2; 95% CI:1.5-6.7) and cigarette smoking (OR:14.7; 95% CI:5.5-39.0 for daily smoking). Prevalence of cough (15.0% vs. 8.5%) and mucus production (22.3% vs. 14.8%) was significantly higher among e-cigarette users compared to non-users, while no difference in lung function was observed. In addition, the prevalence of overweight/obesity was higher among e-cigarette users compared to non-users (36.7% vs. 22.3% with BMI≥25 kg/m²). In conclusion, cigarette smokers and males used e-cigarette more often compared to females and non-cigarette smokers. Attention should be given to respiratory symptoms among e-cigarette users, although our results may be explained by the concurrent use of conventional cigarettes, as the group of exclusive e-cigarette users were too small to allow firm conclusions.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Predicting Adolescent Electronic Cigarette Use: Differences by Never, Ever, and Current Users

OBJECTIVE

Rising rates of adolescent electronic cigarette (ECIG) use is concerning because it can lead to adverse health outcomes and increased risk behavior. There are known predictors of ever versus never ECIG use, but less are known about risk factors for ever versus current use of ECIGs. Problem behavior theory (PBT) was used to evaluate possible risk factors for different ECIG use status.

METHODS

Participants were 573 high school students who completed questionnaires measuring ECIG use, as well as constructs within the Social Environment, Perceived Environment, Personality, and Behavior domains of PBT. Multinomial logistic regression was used to evaluate how predictor variables differentiated between participants who reported (a) never use, (b) ever ECIG use, or (c) current ECIG use.

RESULTS

Adolescents were more likely to endorse ever ECIG use than never use if they reported peer ECIG use, perceived more benefits and fewer costs (e.g., health) of ECIG use, higher extraversion, alcohol and cigarette use (never vs. ever vs. past 30 days), or attended a school with a higher percentage of socioeconomically disadvantaged students. Adolescents were more likely to report current ECIG use than ever ECIG use if they perceived fewer costs of ECIG use or used cannabis in their lifetime (yes/no).

CONCLUSIONS

PBT variables differentiated between ever ECIG use and never ECIG use. However, these variables did not differentiate between ever and current ECIG use. Identifying unique risk factors for current versus ever ECIG use is important to understanding persistent ECIG use and subsequent targeted prevention and intervention programs.

Adolescent electronic cigarette use and tobacco smoking in the Millennium Cohort Study

AIMS

To evaluate the catalyst, diversion and common liability hypotheses by examining associations between e-cigarette use and tobacco cigarette smoking at modal ages 14 and 17 years, controlling for adolescent and infancy risk factors.

DESIGN

Intergenerational, prospective cohort data from the Millennium Cohort Study (MCS). Nationally representative sample of infants born September 2000 to January, 2002.

SETTING

United Kingdom.

PARTICIPANTS

Parent and child data from 10 625 youth assessed in infancy and modal ages 11, 14 and 17 years.

MEASUREMENTS

Age 14 and 17 e-cigarette and combustible cigarette use (recency, frequency). Potential confounders were age 11 risk factors (e.g. alcohol use, externalizing behaviors, parental tobacco use, permissiveness), infancy risk factors (e.g. maternal smoking during pregnancy, smoke exposure in infancy) and demographic characteristics.

FINDINGS

Among youth who had not smoked tobacco by age 14 (n = 9046), logistic regressions estimated that teenagers who used e-cigarettes by age 14 compared with non-e-cigarette users, had more than five times higher odds of initiating tobacco smoking by age 17 [odds ratio (OR) = 5.25, 95% confidence interval (CI) = 3.28-8.38] and nearly triple the odds of being a frequent tobacco smoker at age 17 (OR = 2.91, 95% CI = 1.56-5.41), net of risk factors and demographics. Among youth who had not used e-cigarettes by age 14 (n = 9078), teenagers who had smoked tobacco cigarettes by age 14 had three times higher odds of initiating e-cigarettes by age 17 (OR = 2.98, 95% CI = 1.74-5.09) compared with non-tobacco smokers and nearly three times higher odds of frequently using e-cigarettes at age 17 (OR = 2.90, 95% CI = 1.21-6.95), net of confounders. Similar links between e-cigarette and tobacco cigarette use were observed in regressions following coarsened exact matching.

CONCLUSIONS

E-cigarette use by age 14 is associated with increased odds of tobacco cigarette initiation and frequent smoking at age 17 among British youth. Similarly, tobacco smoking at age 14 is associated with increased odds of both e-cigarette initiation and frequent use at age 17.

Glycerol contained in vaping liquids affects the liver and aspects of energy homeostasis in a sex-dependent manner

Vaping is increasingly popular among the young and adult population. Vaping liquids contained in electronic cigarettes (e-cigarettes) are mainly composed of propylene glycol and glycerol, to which nicotine and flavors are added. Among several biological processes, glycerol is a metabolic substrate used for lipid synthesis in fed state as well as glucose synthesis in fasting state. We aimed to investigate the effects of glycerol e-cigarette aerosol exposure on the aspects of glycerol and glucose homeostasis. Adult and young male and female mice were exposed to e-cigarette aerosols with glycerol as vaping liquid using an established whole-body exposure system. Mice were exposed acutely (single 2-h exposure) or chronically (2 h/day, 5 days/week for 9 weeks). Circulating glycerol and glucose levels were assessed and glycerol as well as glucose tolerance tests were performed. The liver was also investigated to assess changes in the histology, lipid content, inflammation, and stress markers. Lung functions were also assessed as well as hepatic mRNA expression of genes controlling the circadian rhythm. Acute exposure to glycerol aerosols generated by an e-cigarette increased circulating glycerol levels in female mice. Increased hepatic triglyceride and phosphatidylcholine concentrations were observed in female mice with no increase in circulating alanine aminotransferase or evidence of inflammation, fibrosis, or endoplasmic reticulum stress. Chronic exposure to glycerol e-cigarette aerosols mildly impacted glucose tolerance test in young female and male mice. Fasting glycerol, glucose, and insulin remained unchanged. Increased pulmonary resistance was observed in young male mice. Taken together, this study shows that the glycerol contained in vaping liquids can affect the liver as well as the aspects of glucose and glycerol homeostasis. Additional work is required to translate these observations to humans and determine the biological and potential pathological impacts of these findings.

[Risk of initiation to smoking with the use of electronic cigarettes: systematic review and meta-analysis]

This article aims to evaluate the association between the use of electronic cigarettes and initiation to smoking, through a systematic review with meta-analysis of longitudinal studies. A bibliographic search was performed on the MEDLINE, Embase, LILACS and PsycInfo databases. Reference selection, data extraction and risk of bias assessment of the studies were independently carried out in pairs, and the disagreements were discussed with a third researcher to reach a consensus. Meta-analysis was performed using the Mantel-Haenszel random effects model. Among the 25 studies included, 22 evaluated the outcome of conventional cigarette experimentation and nine assessed the outcome of current smoking (in the last 30 days). The meta-analysis showed that the use of electronic cigarettes increased the risk of conventional cigarette experimentation by almost three and a half times (RR=3.42; 95%CI 2.81-4.15), and by more than four times the risk of current smoking (RR=4.32; 95%CI 3.13-5.94). The risk of smoking initiation is significantly higher among electronic cigarette users. The marketing authorization of such devices may represent a threat to public health policies in Brazil.

Social norms as a predictor of smoking uptake among youth: a systematic review, meta-analysis and meta-regression of prospective cohort studies

BACKGROUND AND AIMS

Social norms towards smoking are a key concept in tobacco control policy and research. However, the influence and strength of different types of social norms on youth smoking uptake is unclear. This study aimed to examine, quantify and compare evidence of the longitudinal associations between different types of social norms towards smoking and youth smoking uptake (initiation and escalation).

METHODS

Systematic review searching four databases (MEDLINE, EMBASE, PsycInfo, CINAHL) from January 1998 to October 2020. Evidence synthesis via narrative review, meta-analysis pooling unadjusted associations (initiation only, due to heterogeneity in escalation outcomes) and meta-regression comparing effect sizes by norm type and study characteristics. Studies included observational prospective cohort studies using survey methodology with youth aged ≤24 years. Measurements included longitudinal associations between descriptive norms (perceived smoking behaviour) and injunctive norms (perceived approval/disapproval of smoking) among social network(s) and subsequent smoking initiation or escalation.

RESULTS

Thirty articles were identified. In the narrative review, smoking initiation (but not escalation) was consistently predicted by two norms: parental and close friend smoking. Associations between smoking uptake and other descriptive norms (smoking among siblings, family/household, partner, peers, adults) and all injunctive norms (perceived approval of smoking among parents, siblings, close friends/peers, partner, teachers, people important to you, the public) were less consistent or inconclusive. In the meta-analysis pooling unadjusted associations, 17 articles were included (n = 27 767). Smoking initiation was predicted by the following descriptive norms: smoking among parents [Odds Ratio (OR) = 1.88, 95% Confidence Interval (CI) = 1.56-2.28], close friends (OR = 2.53, 95% CI = 1.99-3.23), siblings (OR = 2.44, 95% CI = 1.93-3.08), family/household (OR = 1.55, 95% CI = 1.36-1.76) and adults (OR = 1.34, 95% CI = 1.02-1.75), but not peers (OR = 1.14, 95% CI = 0.92-1.42). Smoking initiation was also predicted by two injunctive norms, perceived approval of smoking among parents (OR = 1.74, 95% CI = 1.27-2.38) and the public (OR = 4.57, 95% CI = 3.21-6.49), but not close friends/peers (OR = 2.36, 95% CI = 0.86-6.53) or people important to the individual (OR = 1.24, 95% CI = 0.98-1.58).

CONCLUSIONS

In this systematic review (narrative and meta-analysis), descriptive norms of parents' and close friends' smoking behaviour appeared to be consistent predictors of youth smoking initiation, more so than the descriptive norms of more distal social networks and injunctive norms.

Changes in childhood experimentation with, and exposure to, tobacco and e-cigarettes and perceived smoking norms: a repeated cross-sectional study of 10-11 year olds' in Wales

BACKGROUND

Today's primary school children have grown up in a climate of strong smoking restrictions, decreasing tobacco use, and the emergence of e-cigarettes. Children's exposure to tobacco declined substantially in years following the introduction of smoke-free legislation, with smoking uptake and perceived smoking norms declining. There is debate regarding whether emergence of e-cigarettes may interrupt trends in children's smoking perceptions, or offer a means for adults to limit children's exposure to tobacco. This study examines change in children's tobacco and e-cigarettes experimentation (ever use), exposure to secondhand smoking and vaping, and perceived smoking norms.

METHODS

Data from four, repeat cross-sectional surveys of Year 6 primary school pupils (age 10-11 years) in Wales in 2007, 2008, 2014 and 2019 (n = 6741) were combined. E-cigarette use and perceptions were included in 2014 and 2019 surveys. Analyses used binary logistic regression analyses, adjusted for school-level clustering.

RESULTS

Child tobacco experimentation and most indicators of exposure to tobacco smoke indicated a graded decreasing trend over time from 2007 to 2019. Exposure to e-cigarettes increased from 2014 to 2019, as did pupil awareness of e-cigarettes (OR = 2.56, 95%CI = 2.12-3.10), and parental use (OR = 1.26, 95%CI = 1.00-1.57). A decrease in child e-cigarette experimentation was not significant (OR = 0.80, 95%CI = 0.57-1.13). Children's normative perceptions for smoking by adults and children indicated a graded decrease over time (OR = 0.66, 95%CI = 0.54-0.80; OR = 0.69, 95%CI = 0.55-0.86; respectively from 2014 to 2019). However, fewer reported disapproval of people smoking around them in 2019 relative to 2014 (OR = 0.68, 95%CI = 0.53-0.88). Higher exposure to tobacco cigarettes and e-cigarettes in public places, cars and households were associated with favourable normative perceptions for tobacco smoking; however in models adjusted for exposure to both associations of e-cigarette exposure were attenuated.

CONCLUSION

Children's experimentation with and exposure to tobacco, and their perceptions of smoking as a normative behaviour, have continued to decline alongside growth in exposure to e-cigarettes. Although a large majority of pupils reported they minded people smoking around them, there was some evidence of diminishing disapproval of secondhand smoke since 2007. Further research is needed to understand whether use of e-cigarettes in cars and homes is displacing prior smoking or being introduced into environments where smoking had been eliminated.

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.

Prospective association between use of electronic cigarettes and use of conventional cigarettes: a systematic review and meta-analysis

Objective

The aim of this systematic review and meta-analysis was to assess the association between e-cigarette use and subsequent initiation or recurrence of cigarette smoking.

Data sources

A systematic literature search was finalised on 11 November 2019 using PubMed (including MEDLINE), EMBASE, Cochrane Library, Scopus, PubMed Health, NICE Evidence Search, PROSPERO, CRD and PsycInfo.

Study selection

Studies were included if meeting the following criteria: reporting empirical results; longitudinal observational design with a minimum of 3 months of follow-up; including general population samples; allowing for the comparison between users and nonusers of e-cigarettes. Studies rated as having high risk of bias were excluded. Studies were independently assessed by at least two authors. The procedures described by PRISMA were followed, and the quality of evidence was rated using GRADE.

Data synthesis

30 longitudinal studies from 22 different cohorts assessing e-cigarette use among nonsmokers or never-smokers at baseline, and subsequent use of cigarette smoking at follow-up, were included in this review. A random-effects meta-analysis based on 89 076 participants showed a pooled unadjusted odds ratio (OR) of cigarette smoking among baseline nonsmoker e-cigarette users compared with nonusers of 4.68 (CI 3.64–6.02), while the adjusted OR was 3.37 (CI 2.68–4.24). These results were consistent irrespective of whether the outcome was measured as ever-smoking or as past 30-day smoking. The evidence was graded as moderate.

Conclusions

Use of e-cigarettes may predict the initiation or recurrence of cigarette smoking.

This meta-analysis shows that e-cigarette use increases the risk of future initiation or recurrence of cigarette smoking, even after adjusting for potential confounders, suggesting that e-cigarette use could be considered a predictor of subsequent smokinghttps://bit.ly/3buMccm

Association between electronic cigarette use and tobacco cigarette smoking initiation in adolescents: a systematic review and meta-analysis

BACKGROUND

This systematic review of prospective longitudinal primary studies sought to determine whether electronic cigarette (e-cigarette) use by teenagers who had never smoked conventional tobacco cigarettes (tobacco cigarettes) at baseline was associated with subsequently commencing tobacco cigarette smoking.

METHODS

The review followed the principles of a systematic review and meta-analysis. A key word search identified peer-reviewed articles published between 1 January 2005 and 2 October 2019 from seven bibliographic databases and one search engine. Using pre-prepared inclusion/exclusion criteria two researchers independently screened abstracts, and subsequently, full text papers. Selected articles were quality assessed in duplicate. Data on study participants characteristics, exposure and outcome measures were recorded in an adapted Cochrane Data Extraction Form. Feasibility assessment was done to detect clinical heterogeneity and choose an approach to meta-analysis. Analysis comprised pairwise random effects meta-analyses, and sensitivity and subgroup analyses.

RESULTS

From the 6619 studies identified, 14 one-off primary studies in 21 articles were suitable for inclusion. The participants ages ranged from 13 to 19 years and comprised teenagers based in Europe and North America. Nine of the 14 one-off studies, with follow-up periods between 4 and 24 months, met the criteria for inclusion in a meta-analysis of the association between ever use of e-cigarettes and subsequent initiation of tobacco cigarette use. Based on primary study adjusted odds ratios, our meta-analysis calculated a 4.06 (95% confidence interval (CI): 3.00-5.48, I2 68%, 9 primary studies) times higher odds of commencing tobacco cigarette smoking for teenagers who had ever used e-cigarettes at baseline, though the odds ratio were marginally lower (to 3.71 times odds, 95%CI: 2.83-4. 86, I2 35%, 4 primary studies) when only the four high-quality studies were analysed.

CONCLUSION

The systematic review found that e-cigarette use was associated with commencement of tobacco cigarette smoking among teenagers in Europe and North America, identifying an important health-related harm. Given the availability and usage of e-cigarettes, this study provides added support for urgent response by policymakers to stop their use by teenagers to decrease direct harms in this susceptible population group, as well as to conserve achievements in diminishing tobacco cigarette initiation.

Gateway or common liability? A systematic review and meta-analysis of studies of adolescent e-cigarette use and future smoking initiation

BACKGROUND AND AIMS

Studies have consistently found a longitudinal association between e-cigarette use (vaping) and cigarette smoking. Many have interpreted such association as causal. This systematic review and meta-analysis evaluated the plausibility of a causal interpretation by (1) estimating the effect of adolescent vaping on smoking initiation, adjusted for study quality characteristics, (2) evaluating the sufficiency of adjustment for confounding based on the social development model (SDM) and the social ecological model (SEM) and E-value analyses and (3) investigating sample attrition and publication bias.

METHODS

Systematic review and meta-analysis of longitudinal studies that examined the association between e-cigarette use at baseline and smoking at follow-up. Participants were non-smokers aged < 18 at baseline.

RESULTS

Meta-analysis of 11 studies showed a significant longitudinal association between vaping and smoking [adjusted odds ratio (aOR) = 2.93, 95% confidence interval (CI) = 2.22, 3.87]. Studies with sample sizes < 1000 had a significantly higher odds ratio (OR = 6.68, 95% CI = 3.63, 12.31) than studies with sample sizes > 1000 (OR = 2.49, 95% CI = 1.97, 3.15). Overall, the attrition rate was very high (median = 30%). All but one study reported results from complete sample analysis, despite those dropping out having higher risk profiles. Only two studies comprehensively adjusted for confounding. The median E-value was 2.90, indicating that the estimates were not robust against unmeasured confounding.

CONCLUSIONS

There is a longitudinal association between adolescent vaping and smoking initiation; however, the evidence is limited by publication bias, high sample attrition and inadequate adjustment for potential confounders.

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

OBJECTIVE

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

DESIGN

Umbrella review, systematic review and meta-analysis.

DATA SOURCES

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

RESULTS

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

CONCLUSIONS

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

PROSPERO REGISTRATION NUMBER

CRD42020168596.

Smoking among High School Students in Iran: A Meta-Analysis Study

Objective: Cigarette smoking is an important and preventable risk factor, especially for adolescents and high school students. This issue has become one of the challenges for health system. Thus, the present study aimed to investigate the prevalence of smoking among Iranian high school students.

Method: This systematic review and meta-analysis study was done by searching PubMed, Scopus, Web Science (WOS), Science Direct, SID, and Google Scholar using the following keywords: “student” and “smoking” from 2000 to March 2018. After initial and critical appraisal, data were entered into a checklist and analyzed by a comprehensive meta-analysis software.

Results: The prevalence of smoking was 7.9% by combining the results of 49 articles. Males and females had 10.6% and 4.5% smoking prevalence, respectively. The overall prevalence of smoking was higher in northern areas in Iran (22.4%). Males in the northern (22.4%) and females in western regions (5.3%) were more smokers. There was a significant relationship between the prevalence of smoking with the year of publication, sample size, and age (P < 0.001).

Conclusion: In this study, Students' tendency to smoke was different in various regions of Iran, and had a high rate (7.9%). This figure indicates the necessity for planning some coherent educational programs for the public.

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.

Understanding pathways to e-cigarette use across sexual identity: A multi-group structural equation model

This study explored the relationships between sexual violence, smoking behaviors, suicidality and past 30-day e-cigarette use under the theoretical framework of Minority Stress Theory. The 2017 National Youth Risk Behavioral Survey was utilized to study a nationally representative sample of sexual minority (lesbian, gay, bisexual, and unsure) and heterosexual high school students (N = 7882). Multi-group structural equation modeling (SEM) was employed to examine whether sexual violence and suicidality had a direct effect on e-cigarette use, after controlling for prior smoking behaviors (cigarette, cigar, and marijuana use). Suicidality and smoking behaviors were examined as mediators of the relationship between sexual violence and e-cigarette use, and suicidality was examined as a mediator of the relationship between sexual violence and smoking behaviors. This model was tested for invariance across sexual minority and heterosexual students. For both groups, smoking behaviors had significant direct effects on e-cigarette use, yet suicidality revealed no significant direct effects. Both suicidality and sexual violence had significant indirect effects on e-cigarette use through their effects on smoking behaviors. Sexual violence had a significant direct effect on e-cigarette use for sexual minority students, but not for heterosexual students. Despite this notable difference, the model was found to be invariant across the two groups. These findings suggest that students who report sexual violence may experience suicidality and victimization may lead to smoking behaviors and e-cigarette use. Students' mental health and substance use behaviors should continue to be targeted in schools, particularly among sexual minority youths.

E-cigarettes: A novel therapy or a looming catastrophe

Electronic cigarettes (e-cigarettes) were originally developed in 2003 as healthier alternatives to conventional tobacco cigarettes. Their popularity has since significantly increased and both users and nonusers are exposed to their aerosol and product constituents. Although some evidence suggests that e-cigarette use may facilitate smoking cessation, definitive data are lacking and e-cigarettes are not approved by the Food and Drug Administration as a cessation aid. While e-cigarette aerosol contains fewer toxins than conventional cigarette smoke, studies evaluating whether e-cigarettes are less harmful are inconclusive. The health impact of e-cigarettes for both users and nonusers cannot be determined with currently available data, and there are both environmental concerns and issues regarding nonuser exposure. Most of the currently available data related to the health effects of e-cigarettes do not evaluate their effects on the general population and evidence regarding the systemic health effects of e-cigarettes is limited. In addition, there has been a recent rise in vaping-related lung injuries. Therefore, the detrimental effects of e-cigarette use should be further investigated, and every effort should be made to increase public awareness of the harmful effects of e-cigarettes.

Trends in Social Norms Towards Smoking Between 2002 and 2015 Among Daily Smokers: Findings From the International Tobacco Control Four Country Survey (ITC 4C)

OBJECTIVE

To assess trends in daily smokers' social norms and opinions of smoking between 2002 and 2015 in Canada, the United States, the United Kingdom, and Australia.

METHOD

Data were from wave 1 (2002) to wave 9 (2013-2015) of the longitudinal International Tobacco Control Four Country Survey (Canada, the United States, the United Kingdom, Australia), involving 23 831 adult daily smokers. Generalized estimating equation logistic regression models, adjusted for demographics and survey design effects, assessed associations of wave and country with outcomes: (A) over half of five closest friends smoke, (B) agreeing that people important to you believe you should not smoke, (C) agreeing that society disapproves of smoking, and (D) negative opinion of smoking.

RESULTS

Between 2002 and 2015, adjusting for covariates, (A) over half of five closest friends smoke did not change (56% vs. 55%; adjusted odds ratio [AOR] = 0.95 [95% Confidence Interval = 0.85-1.07]), (B) agreeing that people important to you believe you should not smoke generally decreased (89% vs. 82%; AOR = 0.54 [0.46-0.64]) despite an increase around 2006-2007, (C) agreeing that society disapproves of smoking increased between 2002 and 2006-2007 (83% vs. 87%; AOR = 1.38 [1.24-1.54]) then decreased until 2013-2015 (78%; AOR = 0.74 [0.63-0.88]), and (D) negative opinion of smoking decreased between 2002 and 2010-2011 (54% vs. 49%; AOR = 0.83 [0.75-0.91]) despite an increase around 2005-2006 and at the final wave (2013-2015). Except friend smoking, Canada had the greatest, and the United Kingdom the lowest, antismoking social norms and opinions.

CONCLUSIONS

Except friend smoking and opinion of smoking, daily smokers' social norms became less antismoking between 2002 and 2015 despite increases around 2006-2007. Several potential explanations are discussed yet remain undetermined.

IMPLICATIONS

Increasingly comprehensive tobacco control policies alongside decreasing smoking prevalence in Canada, the United States, the United Kingdom, and Australia have led to the assumption that smoking has become denormalized in these countries. Absent from the literature is any formal assessment of social norms towards smoking over time. Contrary to our hypotheses, this study found that the injunctive social norms of daily smokers became less antismoking between 2002 and 2015, despite increases around 2006-2007. There was no change over time in the proportion of daily smokers who report that over half of their five closest friends smoke.

Electronic Vaping Product Use among Young Adults Who Receive Care at a Major Medical Institution

Background: National estimates of electronic vaping product (EVP) use exist, but little is known about young adult EVP users who interact with the healthcare setting. Methods: Cross-sectional survey of 18-25 year olds receiving care in our ambulatory medical practice. Population differences were evaluated with the chi square test reporting unadjusted odds ratios (ORs). Results: Response rate was 16.6% (n = 1,017/6,119). The prevalence of ever EVP use was 46.0% of whom 13.9% used every day. Each additional day of alcohol use (past 30 days) was associated with increased odds of being an EVP user (OR = 1.06, 95% CI 1.02-1.09), and cannabis use (past 30 days) was associated with a higher odds of being an EVP user compared to non-cannabis users (OR = 40.0, 95% CI 17.4 - 111.8). Observing a biological parent (OR = 2.89, 95% CI 1.98-4.24), step parent (OR = 2.03, 95% CI 1.02-4.19) and full sibling (OR = 2.31, 95% CI 1.78-3.00) using inhaled substances (past 30 days) was associated with increased odds of being an ever EVP user. Ever EVP users had lower odds than never users to report that EVPs with nicotine are "a little" or "a lot" more harmful than smoking "regular" tobacco cigarettes (OR = 0.53, 95% CI 0.37 - 0.76). Conclusion: Our survey is limited by a low response rate but confirms observed associations between EVP use and substance use and social influences. Our data also suggest that professionals should regularly screen for EVP use among young people, especially those with exposure to family members who used inhaled substances.

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.

Does having one or more smoking friends mediate the transition from e-cigarette use to cigarette smoking: a longitudinal study of Canadian youth

PURPOSE

Studies have shown consistent associations between youth e-cigarette use and subsequent smoking uptake. However, it remains unclear why, as limited evidence exists regarding the mechanisms underlying these associations. Our study investigated whether having one or more smoking friends mediated the association between e-cigarette use and cigarette smoking onset among a longitudinal sample of Canadian youth who were never smokers at baseline.

METHODS

A longitudinal sample of youth that participated in three waves of the COMPASS study (2015-2016 to 2017-2018) was identified (N = 5,535). The product of coefficients method was used to assess whether having one or more smoking friends mediated the association between: (1) past 30-day e-cigarette use and cigarette smoking onset and (2) past 30-day e-cigarette use and subsequent dual use of e-cigarettes and cigarettes.

RESULTS

Having one or more smoking friends did not mediate the association between (1) past 30-day e-cigarette use and cigarette smoking onset (β = 0.38, 95% CI - 0.12, 0.89) or (2) past 30-day e-cigarette use and subsequent dual use (β = 0.46, 95% CI - 0.16, 1.07). Post hoc tests indicated that smoking friends significantly predicted past 30-day e-cigarette use and cigarette smoking at wave 3 (aOR 1.68 and 2.29, respectively).

CONCLUSION

Having smoking friends did not explain the association between e-cigarette use and smoking uptake despite being a common risk factor for both e-cigarette use and cigarette smoking. Prevention efforts should consider how best to incorporate effective programming to address these social influences.

Changes from 2017 to 2018 in e-cigarette use and in ever marijuana use with e-cigarettes among US adolescents: analysis of the National Youth Tobacco Survey

AIMS

To examine changes from 2017 to 2018 in e-cigarette use and ever marijuana use with e-cigarettes among US adolescents.

DESIGN

Analysis of data from the 2017 and 2018 National Youth Tobacco Survey (NYTS), cross-sectional surveys of US middle school (grades 6-8) and high school (grades 9-12) students.

SETTING

United States.

PARTICIPANTS

US adolescent population from middle school, with mean age = 12.7 [standard deviation (SD) = 1.0] years, and high school, with mean age = 16.1 (SD = 1.3) years.

MEASUREMENTS

Analysis of e-cigarette use and ever use of marijuana with e-cigarettes according to frequency of use and smoking status, comparing 2017 with 2018. Frequent smoking and e-cigarette use was defined as use for ≥ 20 of the past 30 days.

FINDINGS

Past 30 days e-cigarette use was reported by 33.1% [95% confidence interval (CI) = 29.1-37.4%] of ever/no past 30 days smokers, 68.6% (95% CI = 64.1-72.7%) of past 30 days smokers and 7.2% (95% CI = 6.3-8.2%) of never smokers in 2018 and by 19.3% (95% CI = 16.1-23.1%), 53.0% (95% CI = 46.9-58.9%) and 3.3% (95% CI = 2.7-4.4%) in 2017, respectively (all P < 0.001). Prevalence of past 30 days e-cigarette use was higher among frequent smokers (69.8%, 95% CI = 62.3-76.5% in 2018; 53.8%, 95% CI = 44.1-63.2% in 2017, P < 0.001) and lower among never smokers. Most of the latter were infrequent users, while frequent and daily e-cigarette use was 18- and 24-fold lower compared with ever smokers, respectively. Approximately half of past 30 days and 70% of frequent e-cigarette users reported ever marijuana use with e-cigarettes in both years. Past 30 days smokers were more likely to report past 30 days e-cigarette use [odds ratio (OR) = 15.79, 95% CI = 12.58-19.83 in 2018; OR = 16.11, 95% CI = 12.44-20.86 in 2017) compared with adolescents reporting no past 30 days smoking.

CONCLUSIONS

Among US adolescents, e-cigarette use increased in all smoking groups in 2018 compared with 2017. Frequent and daily e-cigarette use was far lower in never-smokers compared with ever-smokers. High prevalence of ever marijuana use with e-cigarettes was observed.

A systematic review of the impact of cigarettes and electronic cigarettes in otology

BACKGROUND

The detrimental systemic effects of cigarette smoking are well established. Though less pronounced in the field of otology, they are proposed to contribute to the global burden of unaddressed hearing loss. Recently, in efforts to stop smoking, individuals have used electronic cigarettes of which the long-term safety data are largely unknown. This study aimed to conduct a systematic review of cigarette smoking and electronic cigarette effects in the field of otology.

METHOD

Relevant articles were identified by a National Institute for Health and Care Excellence healthcare database literature search and by scanning the references of relevant articles and reviews.

RESULTS

A total of 473 articles were identified, with 43 articles included in the review after trials were excluded.

CONCLUSION

Cigarette smoking is associated with recurrent otitis media, otitis media with effusion and sensorineural hearing loss in children exposed to second-hand smoke. In adults, it is associated with active and aggressive chronic suppurative otitis media, worse tympanoplasty success rates, increased post-operative complications and sensorineural hearing loss that is more pronounced in the long term and at high frequencies. The effects of e-cigarettes in otology are largely unknown.

Body Mass Index and stimulus control: Results from a real-world study of eating behaviour

BACKGROUND

Evidence suggests decisions about when, what, and how much to eat can be influenced by external (location, food outlet presence, food availability) and internal (affect) cues. Although the relationship between stimulus control and obesity is debated, it is suggested that individuals with higher BMIs are more driven by cues to eating than individuals in the healthy-weight range (HWR). This study investigates the influence of stimulus control on real-world food intake, and whether stimulus control differs by BMI. It was hypothesised that, compared to those in the HWR, eating among individuals with higher BMIs would be under greater stimulus control.

METHOD

74 participants (n = 34 BMI < 24.9, n = 40 BMI > 24.9) recorded food intake for 14 days using Ecological Momentary Assessment. Participants also responded to 4-5 randomly-timed assessments per day. Known external and internal eating cues were assessed during both assessment types. Within-person logistic regression analyses were used to predict eating vs. non-eating occasions from stimulus control domains.

FINDINGS

Results support the hypothesis that eating was influenced by stimulus control: food availability, affect, time of day, and location significantly distinguished between eating and non-eating instances (AUC-ROC = 0.56-0.69, all p's < 0.001). The presence of food outlets was significantly better at distinguishing between eating and non-eating instances for those with higher BMIs (compared to individuals in the HWR).

DISCUSSION

Results support the notion of stimulus control in shaping eating decisions. Differences in levels of stimulus control between participants in the HWR compared to those with a high BMI suggest that dietary improvement interventions may be more effective when they are tailored to the individual and consider environmental influences on eating behaviour.

College students' reasons for using different e-cigarette products: A mixed methods analysis

This study examined if college students used particular e-cigarette devices for different reasons. Participants: College students from a large southern university completed an online, close- and open-ended survey. Data were delimited to those 18-25 years of age who had used e-cigarettes (n = 338). Methods: A convergent mixed-methods design was employed by quantifying qualitative responses via an inducting coding method. Next, χ² analyses examined relationships between use of different products (i.e., cigalikes, vape pens, eGos, mods) and reasons for using e-cigarettes. Results: Emerging themes representing reasons for trying e-cigarettes included: curiosity, peer pressure, recreation, flavors, better than cigarettes, and to quit/reduce tobacco use. Significant relationships existed between use of cigalikes, (p < . 01), eGos (p < . 05), and mods (p < . 05) and use of e-cigarettes to quitting/reducing tobacco use. Conclusions: Health promotion efforts on college campuses should address curiosity about these products and provide scientifically proven therapy to those seeking to quit tobacco.

Trends and predictors of exclusive e-cigarette use, exclusive smoking and dual use among youth in Canada

BACKGROUND

Few studies have examined predictors of exclusive e-cigarette use, exclusive smoking and dual use among youth. We investigated whether frequency of e-cigarette use and cigarette smoking predicted involvement in different usage groups after a 1- and 2-year follow-up among a sample of Canadian youth.

METHODS

A longitudinal sample of youth who participated in three waves of COMPASS [Wave 1 (W₁) 2015/16, Wave 2 (W₂) 2016-17, Wave 3 (W₃) 2017/18] was identified (N = 5,704). Multinomial logistic regression was used to examine whether frequency of e-cigarette use and cigarette smoking at W₁ predicted involvement in different usage groups at W₂ and W₃. Similarly, we examined whether changes in frequency of e-cigarette use and cigarette smoking between W₁ and W₂ predicted involvement in different usage groups at W₃.

RESULTS

E-cigarette users reporting use on 4 or more days per month at W₁ had greater odds of dual use at W₂, compared to non-users (aOR = 11.22, p < 0.0001). Those who reduced their frequency of e-cigarette use between W₁ and W₂ had lower odds of exclusive e-cigarette use and dual use at W₃ (aOR = 0.18 and 0.17 respectively; both p < 0.05). Those who increased their frequency of cigarette smoking between W₁ and W₂ had higher odds of exclusive smoking and dual use at W₃ (aOR = 22.65 and aOR = 9.92 respectively; both p < 0.0001).

DISCUSSION

Reductions in frequency of e-cigarette use appeared to have a protective effect of reducing exclusive e-cigarette use and dual use at follow-up. Increases in frequency of cigarette smoking were a significant predictor of exclusive smoking and dual use.

Interventions to prevent periodontal disease in tobacco-, alcohol-, and drug-dependent individuals

Substance abuse affects more than one sixth of the world's population. More importantly, the nature of the abuse and the type of addictive substances available to individuals is increasing exponentially. All substances with abusive potential impact both the human immuno-inflammatory system and oral microbial communities, and therefore play a critical role in the etiopathogenesis of periodontal diseases. Evidence strongly supports the efficacy of professionally delivered cessation counseling. Dentists, dental therapists, and hygienists are ideally placed to deliver this therapy, and to spearhead efforts to provide behavioral and pharmacologic support for cessation. The purpose of this review is to examine the biologic mechanisms underlying their role in disease causation, to understand the pharmacologic and behavioral basis for their habituation, and to investigate the efficacy of population-based and personalized interventions in prevention of periodontal disease.

Predictors of JUUL, other electronic nicotine delivery systems, and combustible tobacco initiation among Texas youth

The objectives of this study were to 1) examine longitudinal predictors of JUUL and other tobacco product initiation, 2) compare these predictors across product type, and 3) describe cross-sectional characteristics of JUUL initiators, among a cohort of Texas adolescents. Analyses were also stratified to examine whether predictors of initiation differed by susceptibility to tobacco use at baseline. This study utilized data from Waves 7 and 8 (Fall 2017 and Spring 2018) of the Texas Adolescent Tobacco and Marketing Surveillance System (n = 2272). Chi-square tests and multinomial logistic regressions were conducted to examine differences in predictors of initiation. Among those who initiated at Wave 8 (n=107), 40.2% initiated JUUL, 43.9% initiated other ENDS, and 15.9% initiated other combustible tobacco. For the full sample, ever marijuana use predicted the initiation of all tobacco products (Relative Risk Ratios "RRRs" from 2.31-4.13) as compared to non-users. For non-susceptible youth, ever marijuana use significantly predicted the initiation of JUUL (RRR = 10.08, 95% CI = 2.11-48.17) and other ENDS use (RRR = 12.07, 95% CI = 2.97-49.04). Peer tobacco use predicted the initiation of JUUL (RRR = 3.06, 95% CI = 1.38-6.81) and other ENDS use (RRR = 5.36, 95% CI = 2.11-13.64) for the full sample, as well as those who were susceptible to tobacco use. For non-susceptible youth, peer tobacco use predicted the initiation of combustible tobacco use (RRR = 16.56, 95% CI = 1.56-175.84). Prominent reasons for JUUL use included curiosity, friend use, and less harmful that cigarettes. Results highlight the role of marijuana in the initiation of all tobacco products, even among low-risk youth; other predictors varied between product type. Interventions should address specific predictors to prevent youth from transitioning to tobacco use.

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.

Social norms for e-cigarettes and smoking: associations with initiation of e-cigarette use, intentions to quit smoking and quit attempts: findings from the EUREST-PLUS ITC Europe Surveys

BACKGROUND

Social norms have received little attention in relation to electronic cigarettes (EC). The current study examine social norms for EC use and smoking tobacco, and their associations with (i) initiation of EC use, (ii) intention to quit smoking and (iii) attempts to quit smoking.

METHODS

Cross-sectional and longitudinal data analysis from Waves 1 and 2 of the ITC 6 European Country Survey and corresponding waves from England (the ITC Four Country Smoking and Vaping Survey). Current smokers at baseline, who heard of ECs and provided data at both waves were included (n = 3702). Complex samples logistic regression examined associations between the outcomes and descriptive (seeing EC use in public, close friends using ECs/smoking) and injunctive (public approves of ECs/smoking) norms, adjusting for country, demographics, EC use and heaviness of smoking.

RESULTS

In longitudinal analyses, seeing EC use in public at least some days was the only social norm that predicted initiation of EC use between waves (OR = 1.66, 95%CI = 1.08-2.56). In the cross-sectional analysis, having an intention to quit was associated with seeing EC use in public (OR = 1.37, 95%CI = 1.04-1.81) and reporting fewer than three close friends smoke (OR = 0.59, 95%CI = 0.44-0.80). There was no association between any social norm and making a quit attempt between waves.

CONCLUSIONS

Initiation of EC use is predicted by seeing EC use in public, which was also associated with greater intention to quit smoking. Friends' smoking was associated with lower intention to quit. These findings may allay concerns that increased visibility of ECs is renormalizing smoking amongst current smokers.

Further investigation of gateway effects using the PATH study

Background: Interest exists in whether youth e-cigarette use ("vaping") increases risk of initiating cigarette smoking. Using Waves 1 and 2 of the US PATH study we previously reported adjustment for vaping propensity using Wave 1 variables explained about 80% of the unadjusted relationship. Here data from Waves 1 to 3 are used to avoid over-adjustment if Wave 1 vaping affected variables recorded then. Methods: Main analyses M1 and M2 concerned Wave 2 never smokers who never vaped by Wave 1, linking Wave 2 vaping to Wave 3 smoking initiation, adjusting for predictors of vaping based on Wave 1 data using differing  propensity indices.  M3 was similar but derived the index from Wave 2 data.  Sensitivity analyses excluded Wave 1 other tobacco product users, included other product use as another predictor, or considered propensity for smoking or any tobacco use, not vaping. Alternative analyses used exact age (not previously available) as a confounder not grouped age, attempted residual confounding adjustment by modifying predictor values using data recorded later, or considered interactions with age. Results: In M1, adjustment removed about half the excess OR (i.e. OR-1), the unadjusted OR, 5.60 (95% CI 4.52-6.93), becoming 3.37 (2.65-4.28), 3.11 (2.47-3.92) or 3.27 (2.57-4.16), depending whether adjustment was for propensity as a continuous variable, as quintiles, or the variables making up the propensity score. Many factors had little effect: using grouped or exact age; considering other products; including interactions; or using predictors of smoking or tobacco use rather than vaping. The clearest conclusion was that analyses avoiding over-adjustment explained about half the excess OR, whereas analyses subject to over-adjustment explained about 80%. Conclusions: Although much of the unadjusted gateway effect results from confounding, we provide stronger evidence than previously of some causal effect of vaping, though doubts still remain about the completeness of adjustment.