Conventional Cigarette Use Research Articles

Health effects in COPD smokers who switch to electronic cigarettes: a retrospective-prospective 3-year follow-up.

BackgroundHealth effects of electronic cigarette (EC) use in patients with chronic obstructive pulmonary disease (COPD) are largely unexplored.AimWe present findings from a long-term prospective assessment of respiratory parameters in a cohort of COPD patients who ceased or substantially reduced conventional cigarette use with ECs.MethodsWe prospectively re-evaluated COPD exacerbations, spirometric indices, subjective assessments (using the COPD Assessment Tool [CAT] scores), physical activity (measured by the 6-minute walk distance [6MWD]), and conventional cigarette use in EC users with COPD who were retrospectively assessed previously. Baseline measurements prior to switching to EC use were compared to follow-up visits at 12, 24, and 36 months. Age- and sex-matched regularly smoking COPD patients who were not using ECs were included as reference (control) group.ResultsComplete data were available from 44 patients. Compared to baseline in the EC-user group, there was a marked decline in the use of conventional cigarettes. Although there was no change in lung function, significant improvements in COPD exacerbation rates, CAT scores, and 6MWD were observed consistently in the EC user group over the 3-year period (p<0.01). Similar findings were noted in COPD EC users who also smoked conventional cigarettes (“dual users”).ConclusionThe present study suggests that EC use may ameliorate objective and subjective COPD outcomes and that the benefits gained may persist long-term. EC use may reverse some of the harm resulting from tobacco smoking in COPD patients.

Socioeconomic Disparities in Electronic Cigarette Use and Transitions from Smoking.

Socioeconomic disparities have been established for conventional cigarette use, but not for electronic cigarettes. This study estimates socioeconomic gradients in exclusive use of conventional cigarettes, electronic cigarettes, and dual use (ie, use of both products) among adults in the United States. Analyses consider nationally representative data on 25- to 54-year-old respondents to the 2014-2016 National Health Interview Surveys (N = 50306). Demographically adjusted seemingly unrelated regression models estimate how two socioeconomic status measures-respondent education and household income-relate to current exclusive use of conventional cigarettes, electronic cigarettes, and dual use. Conventional cigarette use exhibits negative education and income gradients, consistent with existing research: -12.9 percentage points (confidence interval [CI]: -14.0, -11.8) if college educated, and -9.5 percentage points (CI: -10.9, -8.1) if household income exceeds 400% of the federal poverty level. These gradients are flatter for dual use (-1.4 [CI: -1.8, -0.9] and -1.9 [CI: -2.5, -1.2]), and statistically insignificant for electronic cigarette use (-0.03 [CI: -0.5, 0.4] and -0.3 [CI: -0.8, -0.2]). Limiting the sample to ever-smokers, higher education is associated with a 0.9 percentage point increase in likelihood of exclusive electronic cigarette use at interview (CI: 0.0, 1.9). Education and income gradients in exclusive electronic cigarette use are small and statistically insignificant, contrasting with strong negative gradients in exclusive conventional cigarette use. Furthermore, more educated smokers are more likely to switch to exclusive e-cigarette use than less educated smokers. Such differential switching may exacerbate socioeconomic disparities in smoking-related morbidity and mortality, but lower the burden of tobacco-related disease. Research has not yet established whether socioeconomic disparities in electronic cigarette (e-cigarette) use resemble those observed for conventional cigarettes. This article uses nationally representative data on US adults aged 25-54 to estimate income and education gradients in exclusive use of conventional cigarettes, e-cigarettes, and dual use. Both gradients are steep and negative for conventional cigarette use, but flat and statistically insignificant for e-cigarette use. Repeating the analysis among ever-smokers indicates that more educated smokers are more likely to transition toward exclusive e-cigarette use than less educated smokers. Such differential substitution may exacerbate disparities in smoking-related morbidity and mortality.

Epithelial-to-mesenchymal transition of A549 lung cancer cells exposed to electronic cigarettes

ObjectivesEpithelial-to-mesenchymal transition (EMT) is the initial step enabling the metastasis of cancer cells, which often leads to death. Although smoking is a major risk factor for lung cancer, there is still widespread use of conventional cigarettes. Recently, the tobacco industry has been transformed by the introduction of electronic cigarettes (ECs), which have lower levels of carcinogens and may provide a safer alternative. Here, we investigate the ability of EC liquids and aerosols to induce an EMT in A549 lung cancer cells. Materials and MethodsHuman adenocarcinoma alveolar basal epithelial cells (A549) were exposed to EC liquids and aerosols from a popular product for 3–8 days. Live cell imaging, EMT biomarker analysis, and machine learning/image processing algorithms were used to characterize changes associated with EMT. ResultsLong-term exposure of A549 cells to menthol or tobacco-flavored EC liquids or aerosols induced an EMT that was characterized by acquisition of a fibroblast-like morphology, loss of cell-to-cell junctions, internalization of E-cadherin, increased motility, and upregulation of other EMT markers. The EMT was concurrent with plasma membrane to nuclear translocation of active β-catenin. ConclusionThis is the first known study to show an EMT of lung cancer cells during exposure to EC products. Because an EMT is an initial step leading to metastasis, an intractable problem that often leads to patient death, this critical finding has significant implications for former or heavy cigarette smokers who are using EC and may be at risk for lung cancer or who may already have a lung tumor.

E-Cigarettes and the Use of Conventional Cigarettes.

In 2015, 12.1% of 12- to 17-year-olds in Germany had reportedly already tried e-cigarette smoking at least once. We carried out a study of the "gateway" hypothesis, according to which the use of e-cigarettes can motivate adolescents to start smoking conventional cigarettes. During the 2015/2016 school year, 2186 tenth-graders in the German states of Lower Saxony and Schleswig-Holstein who had never smoked conventional cigarettes before took part in a survey over a 6-month period (mean age 15.5 years, standard deviation 0.65; 53.6% female). 14.3% of the survey population (313 adolescents) said at the start of the survey period that they had already tried e-cigarettes at least once. By the end of the survey period, 12.3% (268) of those who had never smoked before had begun to experiment with conventional cigarettes. The risk of beginning such experimentation was 2.2 times higher among e-cigarette users. This association remained (relative risk = 2.18 [1.65; 2.83]) after statistical control for age, sex, state, immigrant background, type of school, socioeconomic status, various personality traits (sensation-seeking, impulsivity, anxiety, hopelessness, extraversion, agreeableness, conscientiousness, neuroticism, openness), and the use of alcohol, cannabis, and other illicit drugs. Further analysis revealed that the association between the use of e-cigarettes and the onset of conventional cigarette smoking was stronger among adolescents with low sensation-seeking scores and without any experience of alcohol intoxication. Among adolescents who have never smoked, experimentation with conventional cigarettes is more common in those who have used e-cigarettes. This effect seems to be stronger among adolescents who, in general, have a lower risk of starting to smoke. The 6-month observation period of this study is too short to allow any inference regarding a connection between e-cigarette use and the development of tobacco dependence.

A longitudinal study of risk perceptions and e-cigarette initiation among college students: Interactions with smoking status

BackgroundRecent data suggest that lower perceived risks of e-cigarettes are associated with e-cigarette use in young adults; however, the temporality of this relationship is not well-understood. We explore how perceptions of harmfulness and addictiveness of e-cigarettes influence e-cigarette initiation, and specifically whether this association varies by cigarette smoking status, in a longitudinal study of tobacco use on college campuses. MethodsData are from a 5-wave 24-college study in Texas. Only students who reported never using e-cigarettes at wave 1 were included (n = 2565). Multilevel discrete-time hazard models, accounting for school clustering, were used. The dependent variable, ever e-cigarette use, was assessed at each wave. Both time-varying (e-cigarette perceptions of harmfulness and addictiveness, age, use of cigarettes, use of other tobacco products, and use of other substances) and time-invariant demographic covariates were included. Two-way interactions between each e-cigarette perception variable and current conventional cigarette use were tested to determine if the hypothesized relationship differed among smokers and non-smokers. Results21% of all never e-cigarette users at baseline had initiated e-cigarette ever use by wave 5. Significant two-way interactions qualified the relationship between risk perceptions and e-cigarette initiation. Specifically, perceptions of a lower degree of harmfulness (OR = 1.13, p = .047) and addictiveness (OR = 1.34, p < .001) of e-cigarettes predicted initiation among non-smokers, but not among current smokers. ConclusionPerceiving a lower degree of risk of e-cigarettes contributes to subsequent e-cigarette initiation among non-smokers, but not among current smokers. Findingshave implications for prevention campaigns focusing on the potential harm of e-cigarettes for non-smoking college students.

Impact of an Outdoor Smoking Ban at Secondary Schools on Cigarettes, E-Cigarettes and Water Pipe Use among Adolescents: An 18-Month Follow-Up.

The effectiveness of outdoor smoking bans on smoking behavior among adolescents remains inconclusive. This study evaluates the long-term impact of outdoor school ground smoking bans among adolescents at secondary schools on the use of conventional cigarettes, e-cigarettes (with/without nicotine) and water pipes. Outdoor smoking bans at 19 Dutch secondary schools were evaluated using a quasi-experimental design. Data on 7733 adolescents were obtained at baseline, and at 6 and 18-month follow-up. The impact of outdoor smoking bans on ‘ever use of conventional cigarettes’, ‘smoking onset’, ‘ever use of e-cigarette with nicotine’, ‘e-cigarette without nicotine’, and ‘water pipe’ was measured. Multilevel logistic regression analysis was used. At schools with a ban, implementation fidelity was checked. At schools where a ban was implemented, at 18-month follow-up more adolescents had started smoking compared to the control condition. No effect of implementation of the ban was found for smoking prevalence, e-cigarettes with/without nicotine, and water pipe use. Implementation fidelity was sufficient. No long-term effects were found of an outdoor smoking ban, except for smoking onset. The ban might cause a reversal effect when schools encounter difficulties with its enforcement or when adolescents still see others smoking. Additional research is required with a longer follow-up than 18 months.

What Factors are Associated with Electronic Cigarette, Shisha-Tobacco and Conventional Cigarette Use? Findings from a Cross-Sectional Survey of Australian Adolescents?

ABSTRACTBackground: Adolescents' use of electronic cigarettes and shisha-tobacco increased in several countries during the 2000s, including in the United States, United Kingdom and Canada. Few studies have examined the factors associated with exclusive e-cigarette or shisha-tobacco use and whether adolescents using these substances exclusively differ from those using traditional cigarettes. Objectives: To examine the socio-demographic and behavioural correlates of exclusive e-cigarette and exclusive shisha-tobacco use to those found for users of tobacco cigarettes and multiple nicotine products in Australian adolescents. Methods: Cross-sectional survey of smoking behaviours of a random sample of 4,576 students in the Australian state of Victoria aged 12–17 conducted between June 2014 and December 2014. Results: Overall, 14% of students had used an e-cigarette with 3% using e-cigarettes exclusively. 13% had used shisha-tobacco, with 2% using shisha-tobacco exclusively. Most students (65%) using e-cigarette and shisha-tobacco (67%) had also used tobacco cigarettes. After adjusting for demographic factors, students using e-cigarettes only were more likely to have never used cannabis or drink alcohol in the past year compared to tobacco cigarette users. Compared to tobacco cigarette users, students using only shisha-tobacco were younger, less likely to use cannabis or alcohol or have friends or parents who smoke. Conclusions: Most Australian adolescents who use alternative nicotine and tobacco-related products do so in conjunction with tobacco cigarettes. Students using e-cigarettes or shisha-tobacco exclusively were less likely to use other substances. Australian longitudinal studies are needed to determine whether this group of students are on a pathway to traditional tobacco use.

Bidirectional associations of e-cigarette, conventional cigarette and waterpipe experimentation among adolescents: A cross-lagged model

PurposeWith an increasingly diverse tobacco product market, it is imperative to understand the trajectories of product experimentation in order to design effective prevention programs. This study aims to explore the bidirectional associations of conventional cigarette, e-cigarette and waterpipe experimentation in a large adolescent sample. MethodsLongitudinal assessment of conventional cigarette, e-cigarette and waterpipe use initiation was conducted in a school-based cohort of 1369 9th graders (mean age=14.88 SD=0.48 at baseline) during fall 2014 and reassessed 6-months later using online self-reported questionnaires. Autoregressive cross-lagged analysis within structural equation modeling framework was performed to simultaneously estimate the initiation of these products over a six-month period, controlling for age, gender, and participation in an intervention program to reduce conventional cigarette initiation. ResultsTobacco product lifetime use was prevalent at baseline in the sample: conventional cigarettes (48.4%), e-cigarettes (35.8%), and waterpipe (20.8%). At six-month follow-up, trying conventional cigarettes predicted trying e-cigarette (adjusted odds ratio (AOR)=3.78, CI95%: 2.66–5.37) and trying waterpipe (AOR=2.82, CI95%: 2.00–3.97). Trying e-cigarette predicted trying conventional cigarette (AOR=3.57, CI95%: 1.96–6.49) and trying waterpipe (AOR=1.51, CI95%: 1.07–2.14). Although trying waterpipe predicted trying e-cigarette at follow-up (AOR=2.10, CI95%: 1.30–3.40), its use did not predict trying conventional cigarette (AOR=0.55, CI95%: 0.24–1.30). ConclusionsThe high rates of poly-tobacco use and the bidirectionality of tobacco product experimentation demands comprehensive tobacco control and prevention programs that address the increasingly diverse tobacco product market targeting adolescents.

Does Exposure and Receptivity to E-cigarette Advertisements Relate to E-cigarette and Conventional Cigarette Use Behaviors among Youth? Results from Wave 1 of the Population Assessment of Tobacco and Health Study

Does Exposure and Receptivity to E-cigarette Advertisements Relate to E-cigarette and Conventional Cigarette Use Behaviors among Youth? Results from Wave 1 of the Population Assessment of Tobacco and Health Study

Trajectories of E-Cigarette and Conventional Cigarette Use Among Youth.

Electronic cigarette (e-cigarette) use is common among youth, and there are concerns that e-cigarette use leads to future conventional cigarette use. We examined longitudinal associations between past-month cigarette and e-cigarette use to characterize the stability and directionality of these tobacco use trajectories over time. High school students (N = 808, 53% female) completed surveys across 3 waves (2013, 2014, and 2015) in 3 public schools in Connecticut. Using autoregressive cross-lagged models, we examined bidirectional relationships between past-month cigarette and e-cigarette use over time. Models were adjusted for covariates related to tobacco use (ie, sex, race/ethnicity, socioeconomic status, and use of other tobacco products). Past-month e-cigarette use predicted future cigarette use (wave 1-2: odds ratio [OR] = 7.08, 95% confidence interval [CI] = 2.34-21.42; wave 2-3: OR = 3.87, 95% CI = 1.86-8.06). However, past-month cigarette use did not predict future e-cigarette use (wave 1-2: OR = 2.02, 95% CI = 0.67-6.08; wave 2-3: OR = 1.90, 95% CI = 0.77-4.71). Additionally, frequency of cigarette and e-cigarette use increased over time. By wave 3, 26% of cigarette users and 20.5% of e-cigarette users reported using 21-30 days out of the past month. E-cigarette use was associated with future cigarette use across 3 longitudinal waves, yet cigarette use was not associated with future e-cigarette use. Future research needs to examine mechanisms through which e-cigarette use leads to cigarette use. E-cigarette regulation and prevention programs may help prevent future use of cigarettes among youth.

Adolescent smoking: The relationship between cigarette smoking,E-cigarette smoking and BMI.

Background: There has been rapid growth in ever and current electronic cigarette (e-cigarettes) use over the past 4 years. Use is highest among adolescents and current cigarette smokers. This trend follows a rise in the number of overweight and obese adolescents and teens. This study examined the relationship between BMI and the use of both electronic and conventional cigarette in high school aged youth. Methods: Data from the Youth Risk Behavior Surveillance System (YRBSS)-a nationally representative survey of 9th through 12th grade students conducted every two years-was used for analysis. Two different statistical models-a multinomial logit (mlogit) and quantile regression (QR) of BMI levels-tested the relationship between BMI and electronic/conventional cigarette use among adolescents. Results: BMI was positively related to age, race, and ethnicity. Those who use either conventional or electronic cigarettes had higher BMI than those using neither product. Magnitude vary by demographic groups, particularly among women. While solitary product use was associated with elevated weight, simultaneous use of both products was associated with lower BMI values. Overweight and obese adolescents were more frequent tobacco users than other weight classes. Associations were impervious to model specification. Conclusion: Findings showed that use of either conventional and electronic cigarettes was associated with higher BMI. However, these findings suggest the need for additional research into the health impacts of substance use by adolescents. Research into the physical, emotional and psychological health impacts of electronic tobacco needs to be fully explored as it continues to grow in popularity among adolescents.

Electronic Cigarette and Conventional Cigarette Use among Korean Adults: The 6thKorean National Health and Nutrition Examination Survey, 2013-2015

Electronic Cigarette and Conventional Cigarette Use among Korean Adults: The 6^thKorean National Health and Nutrition Examination Survey, 2013-2015

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

The influence of e-cigarette use on smoking initiation is a highly controversial issue, with limited longitudinal data available for examining temporal associations. We examined e-cigarette use and its association with cigarette-smoking initiation at 1-year follow-up within a large cohort of Canadian secondary school students. We analyzed data from students in grades 9-12 who participated in 2 waves of COMPASS, a cohort study of purposefully sampled secondary schools in Ontario and Alberta, Canada, at baseline (2013/14) and 1-year follow-up (2014/15). We assessed cigarette smoking and e-cigarette use at baseline and follow-up using self-completed surveys. We used generalized linear mixed-effects models to examine correlates of past 30-day e-cigarette use at baseline and smoking initiation between waves within the longitudinal sample. Past 30-day e-cigarette use increased from 2013/14 to 2014/15 (7.2% v. 9.7%, p < 0.001), whereas past 30-day cigarette smoking decreased slightly (11.4% v. 10.8%, p = 0.02). Among the 44 163 students evaluated at baseline, past 30-day e-cigarette use was strongly associated with smoking status and smoking susceptibility. In the longitudinal sample (n = 19 130), past 30-day use of e-cigarettes at baseline was associated with initiation of smoking a whole cigarette (adjusted odds ratio [OR] 2.12, 95% confidence interval [CI] 1.68-2.66) and with initiation of daily smoking (adjusted OR 1.79, 95% CI 1.41-2.28) at follow-up. E-cigarette use was strongly associated with cigarette smoking behaviour, including smoking initiation at follow-up. The causal nature of this association remains unclear, because common factors underlying the use of both e-cigarettes and conventional cigarettes may also account for the temporal order of initiation.

A longitudinal study of electronic cigarette use and onset of conventional cigarette smoking and marijuana use among Mexican adolescents

PurposeThis study evaluated whether e-cigarette trial among Mexican adolescents increased the likelihood of trial and use of conventional cigarettes or marijuana use at follow-up. MethodA school-based longitudinal survey was conducted in 60 public middle schools from the three largest cities in Mexico. Students (12–13 years old) were surveyed in 2015 and followed up 20 months later (n = 6574). Generalized estimating equations models were used to evaluate the association between e-cigarette trial at baseline and conventional cigarettes smoking and marijuana use at follow-up. ResultAdolescents who had tried e-cigarettes (but not cigarettes) at baseline were more likely to have tried conventional cigarettes at followup compared to adolescents who had tried neither e-cigarettes nor cigarettes (43% vs. 24%, respectively; RR 1.41, 95% CI 1.18-1.70). We also found that adolescents who had tried both conventional cigarettes and e-cigarettes at baseline were more likely to have tried marijuana at follow-up compared to adolescents who had tried neither tobacco product (20% vs. 4%, respectively; RR 2.67, 95% CI 1.78–4.02). Trial of only e-cigarettes was not independently associated with marijuana use at followup. ConclusionsAdolescents who had tried e-cigarettes were more likely to have tried conventional cigarettes and marijuana 20 months later. Although e-cigarettes have been banned in Mexico, it is likely that additional policies and public health campaigns are needed to reduce adolescent use of e-cigarettes and its consequences.

Evaluating the mutual pathways among electronic cigarette use, conventional smoking and nicotine dependence.

The implications of the rapid rise in electronic cigarette (e-cigarette) use remain unknown. We examined mutual associations between e-cigarette use, conventional cigarette use and nicotine dependence over time to (1) test the association between e-cigarette use and later conventional smoking (both direct and via nicotine dependence), (2) test the converse associations and (3) determine the strongest pathways predicting each product's use. Data from four annual waves of a prospective cohort study were analyzed. Path analysis modeled the bidirectional, longitudinal relationships between past-month smoking frequency, past-month e-cigarette frequency and nicotine dependence. Chicago area, Illinois, USA. A total of 1007 young adult smokers and non-smokers (ages 19-23years). Frequency of (1) cigarettes and (2) e-cigarettes was the number of days in the past 30 on which the product was used. The Nicotine Dependence Syndrome Scale measured nicotine dependence to cigarettes. E-cigarette use was not associated significantly with later conventional smoking, either directly (β=0.021, P=0.081) or through nicotine dependence (β=0.005, P=0.693). Conventional smoking was associated positively with later e-cigarette use, both directly (β=0.118, P<0.001) and through nicotine dependence (β=0.139, P<0.001). The strongest predictors of each product's use was prior use of the same product; this pathway was strong for conventional cigarettes (β=0.604, P<0.001) but weak for e-cigarettes (β=0.120, P<0.001). Nicotine dependence moderately strongly predicted later conventional smoking (β=0.169, P<0.001), but was a weak predictor of later e-cigarette use (β=0.069, P=0.039). Nicotine dependence is not a significant mechanism for e-cigarettes' purported effect on heavier future conventional smoking among young adults. Nicotine dependence may be a mechanism for increases in e-cigarette use among heavier conventional smokers, consistent with e-cigarettes as a smoking reduction tool. Overall, conventional smoking and, to a lesser extent, its resulting nicotine dependence, are the strongest drivers or signals of later cigarette and e-cigarette use.

Use and Perceptions of Electronic Cigarettes Among Caregivers of Infants and Children with Bronchopulmonary Dysplasia.

Background: Bronchopulmonary dysplasia (BPD) is a chronic lung disease associated with prematurity and very low birth weight. These children have increased morbidity and mortality associated with environmental exposures, such as cigarette smoke. As of 2015, 3.5% of US adults report current use of electronic cigarettes (e-cigarettes) with use increasing over time. Perceptions of e-cigarette harm are poorly understood, and there are no data among caregivers of children with BPD. Methods: Subjects (n = 119) in this study were recruited from the outpatient Johns Hopkins BPD Clinic from January to October 2015. Parental use and perceptions of e-cigarettes were assessed using a questionnaire adapted from the 2012 National Youth Tobacco Survey. Chi-square, t-test, and logistic regression analyses were used to assess characteristics associated with e-cigarette use and caregiver perceptions. Results: A total of 119 caregivers completed the questionnaire with 8% reporting current e-cigarette use and 14% reporting current conventional cigarette use. Households who used conventional cigarettes were eleven times more likely to also use e-cigarettes [odds ratio: 11.3 (95% confidence interval: 2.6-48.2); P = 0.001]. Households reporting conventional cigarette use were less likely to perceive e-cigarette emissions as harmful compared with nonsmoking households. Perceptions of e-cigarette emissions as less harmful to others were associated with conventional cigarette use, current e-cigarette use, and having public insurance. Conclusions: Among our population, both conventional cigarette and e-cigarette smoking households had decreased perceptions of harm regarding e-cigarette emissions to self and others. Our study suggests that e-cigarette use among caregivers is an underrecognized environmental exposure in households of children with BPD.

Perceived Harms and Social Norms in the Use of Electronic Cigarettes and Smokeless Tobacco

Perceptions of harms and social norms influence the use of conventional tobacco cigarettes, but little research is available about their combined relationship with e-cigarette and smokeless tobacco use. We conducted a cross-sectional survey of 309 individuals from central Illinois. We explored (1) demographic predictors of perceived harms and social norms related to e-cigarette and smokeless tobacco use, and (2) whether perceived harms, social norms, or both were important predictors of e-cigarette and smokeless tobacco use. E-cigarette perceptions of harm were consistent across all demographic characteristics. Smokeless tobacco perceptions of harm were unrelated to age, race, and sex, but lower education and income were associated with lower perceived harm (p < .05). E-cigarette social norms were less favorable among non-whites (p < .05) but did not vary by other demographic characteristics. Only less education was associated with more favorable social norms of smokeless tobacco (p < .05). Higher perceived harms were related to lower use of e-cigarettes and smokeless tobacco (p < .05). Perceived social norms were not associated with product use. This study provides preliminary support for implementing broad-based health messaging efforts that focus more on the potential harms of e-cigarette and smokeless tobacco use than on social norms.

The Relationship Between Marijuana and Conventional Cigarette Smoking Behavior from Early Adolescence to Adulthood.

Longitudinal analyses investigated (a) the co-occurrence of marijuana use and conventional cigarette smoking within time and (b) bidirectional associations between marijuana and conventional cigarette use in three developmental periods: adolescence, young adulthood, and adulthood. A cross-lag model was used to examine the bidirectional model of marijuana and conventional cigarette smoking frequency from ages 13 to 33years. The bidirectional model accounted for gender, school-age economic disadvantage, childhood attention problems, and race. Marijuana use and conventional cigarette smoking were associated within time in decreasing magnitude and increased cigarette smoking predicted increased marijuana use during adolescence. A reciprocal relationship was found in the transition from young adulthood to adulthood, such that increased conventional cigarette smoking at age 24years uniquely predicted increased marijuana use at age 27years, and increased marijuana use at age 24years uniquely predicted more frequent conventional cigarette smoking at age 27years, even after accounting for other factors. The association between marijuana and cigarette smoking was found to developmentally vary in the current study. Results suggest that conventional cigarette smoking prevention efforts in adolescence and young adulthood could potentially lower the public health impact of both conventional cigarette smoking and marijuana use. Findings point to the importance of universal conventional cigarette smoking prevention efforts among adolescents as a way to decrease later marijuana use and suggest that a prevention effort focused on young adults as they transition to adulthood would lower the use of both cigarette and marijuana use.

Flavored E-cigarette Use and Cigarette Smoking Susceptibility among Youth.

Research indicates youth e-cigarette use may lead to the use of conventional cigarettes, but the specific effects of flavored e-cigarettes-which greatly appeal to youth-are unknown. Therefore, this study examines how flavored e-cigarette use predicts cigarette smoking susceptibility among youth non-smokers. We used 2014 National Youth Tobacco Survey to explore the relationship between current e-cigarette use (non-use, flavored and plain e-cigarette use) and smoking susceptibility among 18,392 youth non-smokers (ages 11-18 years). Overall, 2.2% and 2.1% of non-smoking youth currently used plain and flavored e-cigarettes. Compared to 30.0% of non-users, 61.1% and 74.1% of plain and flavored e-cigarette users reported smoking susceptibility. Flavored e-cigarette users were more likely to be susceptible than plain e-cigarette users (AOR=1.7, p< .001) and non-users (AOR=3.8, p< .0001). The magnitude of the relationship between flavored e-cigarette use and smoking susceptibility was significantly higher for females (AOR=6.5, p< .01) than males (AOR=2.5, p< .01). Flavored more so than plain e-cigarette use is strongly associated with smoking susceptibility among non-smoking youth. Flavored e-cigarettes are recruiting females and those with low smoking-risk profile to experiment conventional cigarettes. Legislative efforts to ban e-cigarettes with child-friendly flavors should be enhanced.

College students' perceptions of risk and addictiveness of e-cigarettes and cigarettes

ABSTRACTBackground: As conventional cigarette use is declining, electronic cigarette (“e-cigarette”) use is rising and is especially high among college students. Few studies examine dual use of e-cigarettes and cigarettes among this population. This study explores the relationship between dual and exclusive e-cigarette / cigarette use and perceptions of harm and addictiveness of both products. Methods: This is a cross-sectional analysis of data from students attending 24 colleges in Texas (n=5,482). Multinomial logistic regression was employed to test the association between current e-cigarette / cigarette use and perceived harm and addictiveness of both products. Three tobacco groups were included: cigarette only users, e-cigarette only users, and dual users. Results: Dual users reported lower perceived harm of e-cigarettes most consistently (p<0.001, all comparisons). Perceived harm of cigarettes was significantly lower among cigarette only and dual users only, compared to non-users (p<0.001, all comparisons). Compared to non-users, all three groups reported significantly lower perceived addictiveness of e-cigarettes (p<0.001, all comparisons). The same finding was observed for perceived addictiveness of cigarettes, though findings were less consistent for the e-cigarette only group (p<0.02, all comparisons except one). Conclusion: Findings demonstrate that among college students, perceptions of harm and addictiveness of e-cigarettes are lower than those for conventional cigarettes. For both products, perceptions of harm and addictiveness were lower among exclusive and dual users, compared to non-users.