Subsequent Smoking Initiation Research Articles

The association between vaping and subsequent initiation of cigarette smoking in young Australians from age 12 to 17 years: a retrospective cohort analysis using cross-sectional recall data from 5114 adolescents

ObjectiveThe objective of this study was to estimate the association between vaping and subsequent initiation of smoking among Australian adolescents and explore the impact of design and analytical methods in previous studies. MethodsWe conducted a retrospective cohort analysis of cross-sectional data from 5114 Australian adolescents aged 14–17 recalling information on smoking and vaping initiation from age 12 to 17. The outcome was smoking initiation, analysed with negative-binomial regression to estimate incidence rate ratios (IRRs) for vape status (ever-vaped vs never-vaped) as a time-varying exposure. We also re-analysed using the methods of previous studies not accounting for the time-varying nature of e-cigarette exposure. ResultsParticipants (n=5114) were retrospectively followed for 20478 person-years. After adjusting for socio-demographic variables and proxy measures of common liabilities for vaping and smoking, the rate of smoking initiation for those who ever-vaped was nearly 5 times that of those who never-vaped (IRR=4.9; 95% confidence interval: [3.9, 6.0], p<0.001), with IRRs considerably higher at younger ages. Not accounting for the time-varying nature of e-cigarette exposure in re-analysis attenuated the estimated IRR by 44%. ConclusionsControlled analyses indicate that vaping markedly increases the risk of subsequent smoking initiation among Australian adolescents from age 12 to 17, with those aged 12, 13, and 14 bearing an alarmingly disproportionate burden of the elevated risk. Additionally, the relative risk of future smoking due to vaping may have been underestimated in other studies due to methodological differences. Implications for public healthOur findings highlight the need for public health interventions and strict e-cigarette access laws.

Association between vmPFC gray matter volume and smoking initiation in adolescents

Smoking of cigarettes among young adolescents is a pressing public health issue. However, the neural mechanisms underlying smoking initiation and sustenance during adolescence, especially the potential causal interactions between altered brain development and smoking behaviour, remain elusive. Here, using large longitudinal adolescence imaging genetic cohorts, we identify associations between left ventromedial prefrontal cortex (vmPFC) gray matter volume (GMV) and subsequent self-reported smoking initiation, and between right vmPFC GMV and the maintenance of smoking behaviour. Rule-breaking behaviour mediates the association between smaller left vmPFC GMV and smoking behaviour based on longitudinal cross-lagged analysis and Mendelian randomisation. In contrast, smoking behaviour associated longitudinal covariation of right vmPFC GMV and sensation seeking (especially hedonic experience) highlights a potential reward-based mechanism for sustaining addictive behaviour. Taken together, our findings reveal vmPFC GMV as a possible biomarker for the early stages of nicotine addiction, with implications for its prevention and treatment.

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

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. To assess the association of youth baseline e-cigarette use with their continued cigarette smoking 2 years after initiation. 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. Ever and current (past 30-day) use of e-cigarettes in wave 3. Continued cigarette smoking in wave 5 after initiating smoking in wave 4. 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. 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.

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

IntroductionThis study quantifies the longitudinal association between e-cigarette use and subsequent conventional cigarette initiation and vice versa among Thai youths.MethodsData from a longitudinal survey of 6045 Thai seventh grade students...

E-Cigarette Use and Combustible Cigarette Smoking Initiation Among Youth: Accounting for Time-Varying Exposure and Time-Dependent Confounding.

Youth e-cigarette use is associated with the initiation of combustible cigarette smoking, but prior studies have rarely accounted for time-varying measures of e-cigarette exposure or time-dependent confounding of e-cigarette use and smoking initiation. Using five waves of the Population Assessment of Tobacco and Health (2013-2019), we estimated marginal structural models with inverse probability of treatment and censoring weights to examine the association between time-varying e-cigarette initiation and subsequent cigarette smoking initiation among e-cigarette- and cigarette-naïve youth (12-17 years) at baseline. Time-dependent confounders used as predictors in inverse probability weights included tobacco-related attitudes or beliefs, mental health symptoms, substance use, and tobacco-marketing exposure. Among 9,584 youth at baseline, those who initiated e-cigarettes were 2.4 times as likely to subsequently initiate cigarette smoking as youth who did not initiate e-cigarettes (risk ratio = 2.4, 95% confidence interval [CI] = 2.1, 2.7), after accounting for time-dependent confounding and selection bias. Among youth who initiated e-cigarettes, more frequent vaping was associated with greater risk of smoking initiation (risk ratio ≥3 days/month = 1.8, 95% CI = 1.4, 2.2; 1-2 days/month = 1.2; 95% CI = 0.93, 1.6 vs. 0 days/month). Weighted marginal structural model estimates were moderately attenuated compared with unweighted estimates adjusted for baseline-only confounders. At the US population level, we estimated over half a million youth initiated cigarette smoking because of prior e-cigarette use over follow-up. The association between youth vaping and combustible cigarette smoking persisted after accounting for time-dependent confounding. We estimate that e-cigarette use accounts for a considerable share of cigarette initiation among US youth. See video abstract at, http://links.lww.com/EDE/B937.

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

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). 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 ≤24years. 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. 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). 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.

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

IntroductionElectronic 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. MethodsBoys 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. ResultsCompared 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). ConclusionsAdolescent 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.

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

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. 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. 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. 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.

Association between e-cigarette use and future combustible cigarette use: Evidence from a prospective cohort of youth and young adults, 2017–2019

IntroductionA surge in popularity of e-cigarettes prompts concern given the association between e-cigarettes and future cigarette use. However, much of the evidence for this association comes from early, less efficient, and lower nicotine e-cigarettes than are available and widely used now. The goal of this study was to examine the relationship between e-cigarette use in 2018 and subsequent smoking initiation and continued e-cigarette use. MethodsParticipants included members of a national longitudinal panel of youth and young adults aged 15–27 who, in 2017, reported never having used a nicotine containing product (n = 3360). Logistic regression analyses assessed associations between participants’ self-reported ever e-cigarette use in 2018 and ever cigarette use, current cigarette use, and current e-cigarette use in 2019, after controlling for demographic and psychosocial variables. ResultsCompared with those who still had never used an e-cigarette, those who reported ever e-cigarette use in 2018 had significantly higher odds of ever cigarette use (aOR = 7.29, 95% CI [4.10, 12.97]), current cigarette use (aOR = 8.26, 95% CI [3.17, 21.53]), and current e-cigarette use (aOR = 9.70, 95% CI [6.41, 14.69]) one year later in 2019. ConclusionsThese findings show that the pod mod style, high nicotine containing e-cigarettes subject young users to the same risks of transitioning to combustible cigarettes as their earlier, less efficient predecessors. Strong regulation of all nicotine products, including e-cigarettes, is needed to prevent the trajectory of e-cigarette to cigarette use among youth and young adults.

Associations of Flavored e-Cigarette Uptake With Subsequent Smoking Initiation and Cessation

Several states have banned sales of flavored e-cigarettes, but evidence on the association between vaping flavors and subsequent smoking initiation and cessation is limited. To evaluate whether new uptake of flavored e-cigarettes is more strongly associated with subsequent smoking initiation and cessation than uptake of unflavored e-cigarettes, separately for youths (12-17 years), emerging adults (18-24 years), and prime-age adults (25-54 years). This cohort study conducted secondary data analyses of longitudinal survey data from waves 1 to 4 of the Population Assessment of Tobacco and Health Study (collected from 2013 to 2018). The analytic sample was limited to 17 929 respondents aged 12 to 54 years at wave 1 who completed at least 3 consecutive waves of the survey and did not use e-cigarettes at baseline. Data were collected from 2013 to 2018 and analyzed in February 2020. Flavored vs unflavored e-cigarette use reported in wave 2 of the Population Assessment of Tobacco and Health Study. Binary indicators captured wave 3 smoking among 7311 youths and 4634 emerging adults who did not smoke at baseline (ie, initiation) and not smoking at wave 3 among 1503 emerging adults and 4481 prime-age adults who smoked at baseline (ie, cessation). Smoking status was based on having smoked in the past 30 days for youths and established smoking (ie, current smoking among those who smoked at least 100 cigarettes in their lifetime) for emerging and prime-age adults. The youths who did not smoke at baseline, emerging adults who smoked at baseline, and prime-age adults who smoked at baseline consisted of 51.4% to 58.0% male participants and 66.9% to 77.0% white individuals. Vaping uptake was positively associated with smoking initiation in youth (adjusted odds ratio [AOR], 6.75; 95% CI, 3.93-11.57; P < .001) and in emerging adults (AOR, 3.20; 95% CI, 1.70-6.02; P < .001). Vaping uptake was associated with cessation in adults (AOR, 1.34; 95% CI, 1.02-1.75; P = .03). Vaping nontobacco flavors was no more associated with youth smoking initiation than vaping tobacco-flavors (AOR in youth, 0.66; 95% CI, 0.16-2.76; P = .56) but was associated with increased adult smoking cessation (AOR in adults, 2.28; 95% CI, 1.04-5.01; P = .04). In this study, adults who began vaping nontobacco-flavored e-cigarettes were more likely to quit smoking than those who vaped tobacco flavors. More research is needed to establish the relationship between e-cigarette flavors and smoking and to guide related policy.

Does e-cigarette experimentation increase the transition to daily smoking among young ever-smokers in France?

IntroductionAccording to multiple studies, e-cigarette use among adolescents is associated with subsequent smoking initiation. However, little is known about its effect on the transition from smoking initiation to daily smoking. MethodsUsing retrospective data from a French national representative survey collected in 2017 (n = 39,115), we analyzed the role of ever using e-cigarettes on daily cigarette smoking status at 17 among ever smokers (n = 21,401). Risk-ratios (RR) were computed through modified Poisson regressions with an inverse probability of treatment weighting (IPTW) approach. ResultsAmong French adolescents aged 17, 16.8 % declared current e-cigarette use (1.9 % reported daily use) and 34.1 % cigarette smoking (25.1 % reported daily smoking). Among ever-smokers, adolescents who declared having ever used e-cigarettes were less likely than those who did not to transition to daily smoking at 17: RR = 0.62 95 %CI [0.60 – 0.64]. We found similar results for those who experimented with e-cigarettes before initiating smoking, RR = 0.76 95 %CI [0.66 – 0.89]. ConclusionsOur results found no evidence of an increased risk of transitioning to daily smoking at 17 among ever-smokers who also experimented with e-cigarettes. Further studies should investigate the longer-term role of vaping on future smoking habits with the use of causal inference methods.

The importance of social environment in preventing smoking: an analysis of the Dead Cool intervention

BackgroundAn adolescent’s perceptions of their family’s and friends’ smoking attitudes and behaviour can influence their own uptake of smoking. There are two broad sources of such social influence: observing the behaviour directly, and assimilating attitudes.MethodsWe analysed data collected for the evaluation of Dead Cool, a school based smoking prevention intervention in Northern Ireland (n=480 in 20 clusters). The main analysis fits three nested logistic regression models predicting pre-intervention susceptibility to taking up smoking, as reflected in responses to three attitudinal questions. Model 1 includes only personal characteristics as explanatory factors. Model 2 adds the behaviour of friends and family that would provide an opportunity for social influence through observational learning. Model 3 adds the susceptibility of friends.ResultsEach additional group of variables improved the model fit (with reduced AIC and BIC). However, in the final model, only three variables were found to be statistically significant (p<0.05) in predicting susceptibility to smoking initiation: rebelliousness (OR [1.1,1.3]) from the personal characteristics group; and, in the observational learning group, being friends with a smoker (OR [1.0,2.9]) and frequency of being in the same room or car with someone smoking (OR [2.0,9.0] for most frequent). Adding the two measures of diffusion of susceptibility through the friendship network improved the model fit, but neither was found to be statistically significant.ConclusionsThe analysis provides additional evidence to support policies that could reduce children’s exposure to smoking behaviour, and potential subsequent smoking initiation. No conclusions could be drawn about the diffusion of smoking attitudes through the school friendship networks of children.

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

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

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

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

Low Self-Esteem for Physical Appearance Mediates the Effect of Body Mass Index on Smoking Initiation Among Adolescents

Adolescence is a period during which youth may begin experimenting with substances. Youth with overweight or obesity may be at increased risk for substance use, including cigarette smoking. Understanding the associations between smoking and excess weight and the pathways associated with increased likelihood for smoking initiation is of particular importance given the increased risk for negative health outcomes associated with each. Using longitudinal panel data from 1,023 middle school youth (baseline age M = 12.5, 52% female), we tested whether smoking initiation was concurrently and prospectively predicted by self-reported body mass index (BMI) and whether self-esteem for physical appearance (SEPA) mediated the effect of BMI on risk of early initiation. BMI predicted smoking initiation concurrently and prospectively in unadjusted models. In adjusted models, SEPA mediated the effects of BMI on smoking initiation. Bootstrapped mediation results indicated that the positive relationship between BMI and subsequent smoking initiation was significantly mediated by lower SEPA (B =.10, 95% confidence interval [0.01, 0.22]). Adolescents who have overweight or obesity are more likely to feel negatively about their appearance and bodies, and this negative perception may result in experimentation with cigarettes. Cigarettes may be used by youth with overweight or obesity in an effort to manage weight, to cope with low self-esteem or for other reasons. Future research should explore the motives and psychosocial context of smoking initiation among adolescents with overweight/obesity further (e.g., with whom they first try smoking, perceived benefits of smoking).

Longitudinal Examination of the Influence of Individual Posttraumatic Stress Disorder Symptoms and Clusters of Symptoms on the Initiation of Cigarette Smoking.

The aim of this study was to determine whether specific individual posttraumatic stress disorder (PTSD) symptoms or symptom clusters predict cigarette smoking initiation. Longitudinal data from the Millennium Cohort Study were used to estimate the relative risk for smoking initiation associated with PTSD symptoms among 2 groups: (1) all individuals who initially indicated they were nonsmokers (n = 44,968, main sample) and (2) a subset of the main sample who screened positive for PTSD (n = 1622). Participants were military service members who completed triennial comprehensive surveys that included assessments of smoking and PTSD symptoms. Complementary log-log models were fit to estimate the relative risk for subsequent smoking initiation associated with each of the 17 symptoms that comprise the PTSD Checklist and 5 symptom clusters. Models were adjusted for demographics, military factors, comorbid conditions, and other PTSD symptoms or clusters. In the main sample, no individual symptoms or clusters predicted smoking initiation. However, in the subset with PTSD, the symptoms "feeling irritable or having angry outbursts" (relative risk [RR] 1.41, 95% confidence interval [CI] 1.13-1.76) and "feeling as though your future will somehow be cut short" (RR 1.19, 95% CI 1.02-1.40) were associated with increased risk for subsequent smoking initiation. Certain PTSD symptoms were associated with higher risk for smoking initiation among current and former service members with PTSD. These results may help identify individuals who might benefit from more intensive smoking prevention efforts included with PTSD treatment.

Association of Noncigarette Tobacco Product Use With Future Cigarette Smoking Among Youth in the Population Assessment of Tobacco and Health (PATH) Study, 2013-2015

Approximately 90% of adult smokers first tried a cigarette by 18 years of age, and even infrequent smoking in adolescence is associated with established adult smoking. Noncigarette tobacco use is increasing and could stimulate subsequent conventional cigarette smoking in youths. To estimate the longitudinal association between noncigarette tobacco use and subsequent cigarette smoking initiation among US youth. In this prospective cohort study of the Population Assessment of Tobacco and Health (PATH) waves 1 (September 12, 2013, to December 14, 2014) and 2 (October 23, 2014, to October 30, 2015), a nationally representative sample of youths who never smoked a conventional cigarette at baseline and completed wave 2 follow-up (N = 10 384) was studied. PATH retention at follow-up was 87.9%. Ever use and past 30-day use of electronic cigarettes (e-cigarettes), hookah, noncigarette combustible tobacco, or smokeless tobacco at baseline. Ever use and past 30-day use of cigarettes at follow-up. The present analysis was based on the 10 384 PATH youth respondents who reported never having smoked a cigarette in wave 1 and whose cigarette ever or past 30-day use was reported in wave 2 (mean [SD] age, 14.3 [1.7] years; age range, 12-17 years; 5087 [49.1%] female; 4829 [52.5%] white). At 1-year follow-up, 469 (4.6%) of all baseline never-smoking youths had tried a cigarette and 219 (2.1%) had smoked a cigarette within the past 30 days. Cigarette ever use at follow-up was higher among youths who had ever used e-cigarettes (78 [19.1%]), hookah (60 [18.3%]), noncigarette combustible tobacco (45 [19.2%]), or smokeless tobacco (29 [18.8%]) at baseline. After adjusting for sociodemographic, environmental, and behavioral smoking risk factors and for baseline ever use of other tobacco products, the odds of past 30-day cigarette use at follow-up were approximately twice as high among baseline ever users of e-cigarettes (odds ratio [OR], 1.87; 95% CI, 1.15-3.05), hookah (OR, 1.92; 95% CI, 1.17-3.17), noncigarette combustible tobacco (OR, 1.78; 95% CI, 1.00-3.19), and smokeless tobacco (OR, 2.07; 95% CI, 1.10-3.87). Youths who had tried more than 1 type of tobacco product at baseline had 3.81 (95% CI, 2.22-6.54) greater adjusted odds of past 30-day cigarette smoking at follow-up than did baseline never tobacco users. Any use of e-cigarettes, hookah, noncigarette combustible tobacco, or smokeless tobacco was independently associated with cigarette smoking 1 year later. Use of more than 1 product increased the odds of progressing to cigarette use.

Association Between Initial Use of e-Cigarettes and Subsequent Cigarette Smoking Among Adolescents and Young Adults

The public health implications of e-cigarettes depend, in part, on whether e-cigarette use affects the risk of cigarette smoking. To perform a systematic review and meta-analysis of longitudinal studies that assessed initial use of e-cigarettes and subsequent cigarette smoking. PubMed, EMBASE, Cochrane Library, Web of Science, the 2016 Society for Research on Nicotine and Tobacco 22nd Annual Meeting abstracts, the 2016 Society of Behavioral Medicine 37th Annual Meeting & Scientific Sessions abstracts, and the 2016 National Institutes of Health Tobacco Regulatory Science Program Conference were searched between February 7 and February 17, 2017. The search included indexed terms and text words to capture concepts associated with e-cigarettes and traditional cigarettes in articles published from database inception to the date of the search. Longitudinal studies reporting odds ratios for cigarette smoking initiation associated with ever use of e-cigarettes or past 30-day cigarette smoking associated with past 30-day e-cigarette use. Searches yielded 6959 unique studies, of which 9 met inclusion criteria (comprising 17 389 adolescents and young adults). Study quality and risk of bias were assessed using the Newcastle-Ottawa Scale and the Risk of Bias in Non-randomized Studies of Interventions tool, respectively. Data and estimates were pooled using random-effects meta-analysis. Among baseline never cigarette smokers, cigarette smoking initiation between baseline and follow-up. Among baseline non-past 30-day cigarette smokers who were past 30-day e-cigarette users, past 30-day cigarette smoking at follow-up. Among 17 389 adolescents and young adults, the ages ranged between 14 and 30 years at baseline, and 56.0% were female. The pooled probabilities of cigarette smoking initiation were 30.4% for baseline ever e-cigarette users and 7.9% for baseline never e-cigarette users. The pooled probabilities of past 30-day cigarette smoking at follow-up were 21.5% for baseline past 30-day e-cigarette users and 4.6% for baseline non-past 30-day e-cigarette users. Adjusting for known demographic, psychosocial, and behavioral risk factors for cigarette smoking, the pooled odds ratio for subsequent cigarette smoking initiation was 3.62 (95% CI, 2.42-5.41) for ever vs never e-cigarette users, and the pooled odds ratio for past 30-day cigarette smoking at follow-up was 4.28 (95% CI, 2.52-7.27) for past 30-day e-cigarette vs non-past 30-day e-cigarette users at baseline. A moderate level of heterogeneity was observed among studies (I2 = 60.1%). e-Cigarette use was associated with greater risk for subsequent cigarette smoking initiation and past 30-day cigarette smoking. Strong e-cigarette regulation could potentially curb use among youth and possibly limit the future population-level burden of cigarette smoking.

School bullying and susceptibility to smoking among never-tried cigarette smoking students

IntroductionBullying involvement has been linked with substance use; however, less is known about its relationship with pre-initiation stages of adolescent cigarette smoking behavior. This study examined the association between bullying involvement and smoking susceptibility among never tried or experimented with cigarette smoking students. Susceptibility to cigarette smoking in adolescence is a strong predictor of subsequent smoking initiation. MethodsA cross-sectional data on Canadian adolescent and youth were drawn from the 2012/2013 Youth Smoking Survey (n=28,843). Logistic regression analysis was used to examine the association between bullying and smoking susceptibility among never-smoking students. ResultsAbout 21% self-reported involvement in bullying (as a bully, victim or both). Middle school students (grades 6–8) reported more involvement in bullying (24%) than those in grades 9–12 (16%). The multivariable analyses showed that the association between bullying and smoking susceptibility was significantly different by grade level. Middle school students involved in bullying had higher odds of smoking susceptibility compared to uninvolved students (bully, adjusted odds ratio [AOR]=2.54, 95% CI=1.73–3.74; victim, AOR=1.29, 95% CI=1.11–1.48; bully–victim, AOR=2.19, 95% CI=1.75–2.74). There were no significant associations between all subgroups of bullying and smoking susceptibility for grades 9–12 students. ConclusionsStudents involved in bullying were more susceptible to smoking, although patterns of association varied by grade level. In particular, the findings highlight that non-smoking middle school students involved in bullying were susceptible to future smoking.

Smoking Initiation Among Mexican Heritage Youth and the Roles of Family Cohesion and Conflict

PurposeHigh levels of family conflict increase the risk for early smoking initiation and smoking escalation among adolescents, whereas high levels of warmth and cohesion in the family are protective against smoking initiation. However, little is known about the associations between changes in family function during adolescence on subsequent smoking initiation among Mexican heritage adolescents. MethodsIn 2005–2006, 1,328 Mexican heritage adolescents aged 11–14 years enrolled in a cohort study to examine nongenetic and genetic factors associated with cigarette experimentation. In 2008–2009, 1,154 participants completed a follow-up. Multivariate logistic regression models were computed to prospectively examine associations between smoking behavior assessed in 2008–2009 and changes in family cohesion and family conflict assessed in both 2005–2006 and 2008–2009, controlling for gender, age, and linguistic acculturation, positive outcome expectations associated with smoking, as well as friends and family smoking behavior. ResultsOverall 21% had tried cigarettes by 2008–2009. Consistently low levels of family cohesion (odds ratio [OR] = 3.06; 95% confidence interval [CI], 1.38–6.73) and decreases in family cohesion (OR = 2.36; 95% CI, 1.37–4.07), as well as consistently high levels of family conflict (OR = 1.74; 95% CI, 1.08–2.79) and increases in conflict (OR = 1.87; 95% CI, 1.19–2.94) were independent risk factors for smoking initiation among Mexican heritage youth. ConclusionsOur findings suggest that family cohesion protects against adolescent smoking, whereas family conflict increases the risk for smoking. Therefore, intervention programs for adolescents and parents could focus on enhancing family bonding and closeness, which is protective against smoking initiation.