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Despite laws prohibiting sale of e-cigarettes to individuals aged less than 21 years, many underage young adults purchase e-cigarettes from retail stores, which may increase likelihood of continued use due to a greater access to vaping products and exposure to point-of-sale marketing.Data are from a prospective cohort of young adults aged 18-20 years in Los Angeles who had ever used e-cigarettes at baseline (N = 1,029). We evaluated the association of underage e-cigarette purchasing behavior (owned and purchased vs. owned but never purchased vs. never owned an e-cigarette) with subsequent vaping frequency, intensity, and dependence symptoms one year later, adjusting for vaping behaviors prior to baseline; additional models evaluated whether associations differed by purchase location or product type.At baseline, 332 (32%) had purchased e-cigarettes while underage, 227 (22%) owned but never purchased e-cigarettes themselves, and 470 (46%) never owned an e-cigarette. Compared to never owning e-cigarettes, those who had purchased their own e-cigarettes vaped more days in the past month (rate ratio [RR] = 2.97; 95% confidence interval [CI]: 2.15-4.09), had more vaping episodes per day (RR: 2.58; 95% CI: 2.12-3.14), vaped more puffs per vaping episode (RR: 1.90; 95% CI: 1.61-2.23), and had greater odds of dependence (odds ratio: 3.68; 95% CI: 2.51-5.40); elevated estimates were also observed for those who owned but never purchased e-cigarettes (vs. never owned). Vaping dependence was greatest among participants who purchased JUULs or other pod-mods.Participants who purchased e-cigarettes underage subsequently vaped more intensely and had greater vaping dependence. Regulations that reduce underage retail access to e-cigarettes may help prevent vaping progression among those most at risk of dependence.

Introduction Understanding the reasons young adults use e-cigarettes (ie, vape)—and whether these motivations vary across groups—is essential for informing tobacco regulatory efforts. Aims and Methods An online panel of young adults who vape (n = 230; age = 18–30 years) completed a maximum difference discrete choice task for 15 reasons for vaping. Over 9 choice sets, participants were presented a subset of 5 reasons and selected the most and least important. Hierarchical bayesian analysis estimated the relative importance of each reason. Latent class analysis (LCA) identified groups with similarly ranked reasons for use. Multinomial regression evaluated the association between sample characteristics and class membership. Results Overall, relaxation had the highest probability of being the most important reason for use (14.8%), followed by harm reduction (13.2%), and flavors (10.3%). LCA identified five distinct classes, based on top reasons for use: 1. cessation (cigarette cessation [20.2%]; n = 80); 2. dependence (relaxation [20.5%] and unable to quit [19.2%]; n = 21); 3. relaxation (relaxation [20.6%]; n = 66); 4. socializing (socializing [22.2%]; n = 27); and 5. variable (boredom [10.5%] and acceptability [10.2%]; n = 36). Participants who were older, smoked cigarettes, or vaped more frequently were more likely to belong to the cessation class while those who were younger or more e-cigarette dependent were more likely to belong to the dependence class. Conclusions Perceived reasons why young adults vape are highly heterogeneous and dependent on the type of user. Tobacco regulatory efforts targeting distinct types of vapers are needed to minimize the adverse public health impact of vaping without compromising appeal for smoking cessation. Implications E-cigarette use remains high among young adults, with flavors, cost, and harm reduction (vs. combustible cigarettes) among the mostly commonly reported reasons for use. Yet, little is known about how relatively important these reasons are to the individual. Leveraging a maximum difference task, young adults’ reasons for use were evaluated on a common interval scale and groups sharing similar reasons identified. Smoking cessation, dependence, relaxation, socialization, and boredom were respectively the most important reasons for use among five classes of vapers. E-cigarette regulatory policies should consider the distinct reasons for use as to not compromise their appeal for smoking cessation.

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.

Rationale Specific cannabis products may differentially increase risk of initiating non-cannabis illicit drug use during adolescence. Objective To determine whether ever- and poly-use of smoked, vaporized, edible, concentrate, or blunt cannabis products are associated with subsequent initiation of non-cannabis illicit drug use. Methods High school students from Los Angeles completed in-classroom surveys. The analytic sample (N = 2163; 53.9% female; 43.5% Hispanic/Latino; baseline M age = 17.1 years) included students who reported never using illicit drugs at baseline (spring, 11th grade) and provided data at follow-up (fall and spring, 12th grade). Logistic regression models assessed associations between use of smoked, vaporized, edible, concentrate, and blunt cannabis at baseline (yes/no for each product) and any non-cannabis illicit drug use initiation—including cocaine, methamphetamine, psychedelics, ecstasy, heroin, prescription opioids, or benzodiazepines—at follow-up. Results Among those who never used non-cannabis illicit drugs at baseline, ever cannabis use varied by cannabis product (smoked = 25.8%, edible = 17.5%, vaporized = 8.4%, concentrates = 3.9%, and blunts = 18.2%) and patterns of use (single product use = 8.2% and poly-product use = 21.8%). After adjustment for baseline covariates, odds of illicit drug use at follow-up were largest for baseline ever users of concentrates (aOR [95% CI] = 5.74[3.16–10.43]), followed by vaporized (aOR [95% CI] = 3.11 [2.41–4.01]), edibles (aOR [95% CI] = 3.43 [2.32–5.08]), blunts (aOR [95% CI] = 2.66[1.60–4.41]), and smoked (aOR [95% CI] = 2.57 [1.64–4.02]) cannabis. Ever use of a single product (aOR [95% CI] = 2.34 [1.26–4.34]) or 2 + products (aOR [95% CI] = 3.82 [2.73–5.35]) were also associated with greater odds of illicit drug initiation. Conclusions For each of five different cannabis products, cannabis use was associated with greater odds of subsequent illicit drug use initiation, especially for cannabis concentrate and poly-product use.

BACKGROUND: Sexual identity is dynamic, and changes in identity (e.g., from heterosexual to lesbian, gay, bisexual, or queer [LGBQ+]) are common during young adulthood. It is not well-understood how sexual identity changes may be associated with substance use risk. METHODS: Two waves of data (baseline: October, 2018–October, 2019; follow-up: May–October, 2020) were used from a prospective cohort of young adults (N = 1896; mean age=21.2). Frequency of past 30-day use and new initiation of five substance use outcomes (alcohol, any tobacco, e-cigarettes, cannabis, illicit drugs) were compared across four groups: consistently heterosexual (N = 1567), consistently LGBQ+ (N = 244), heterosexual to LGBQ+ (N = 65), and LGBQ+ to heterosexual (N = 20). RESULTS: Consistently LGBQ+ (vs. consistently heterosexual) participants reported greater frequency of past 30-day use of alcohol (aOR=1.34, 95% CI=1.04–1.72), any tobacco products (aOR=1.88, CI=1.34–2.63), e-cigarettes (aOR=1.49, CI=1.01–2.19), cannabis (aOR=1.36, CI=1.01–1.84), and illicit drugs (aOR=2.84, CI=1.77–4.56). Heterosexual to LGBQ+ (vs. consistently heterosexual) participants reported greater frequency of past 30-day use of any tobacco products (aOR=1.87, CI=1.06–3.33) and illicit drugs (aOR=2.48, CI=1.10–5.62), and had greater risk of initiating alcohol (aRR=1.82, CI=1.02–3.25) and cannabis use (aRR=2.90, CI=1.81–4.64). LGBQ+ to heterosexual (vs. consistently LGBQ+) participants reported lower frequency of past 30-day use of alcohol (aOR=0.35, CI=0.14–0.88) and any tobacco products (aOR=0.15, CI=0.03–0.80). CONCLUSIONS: Identifying as LGBQ+ was associated with increased risk for frequent substance use, and newly adopting an LGBQ+ identity was associated with increased risk for new substance use initiation. Prevention and treatment interventions may need to tailor messaging to young people who have newly adopted an LGBQ+ identity.

Modern oral nicotine products (ONPs; nontherapeutic nicotine pouches, gums, lozenges, and gummies) may be perceived in ways that could promote uptake in nonvapers, dual use with e-cigarettes, or use to quit vaping. In this cross-sectional digital remote survey of 1,460 respondents aged 21–24 from Southern California, we examined beliefs about ONPs among past-30-day e-cigarette nonusers, users unmotivated to quit vaping, and users motivated to quit vaping. Positive beliefs about ONPs were reported by 31.8% of the overall sample and higher in past-30-day e-cigarette users (with or without quit motivation) than nonusers. Perceiving ONPs to be easy to conceal, convenient, and able to be used where vaping/smoking is not allowed were the most common types of beliefs reported. Among e-cigarette users with quit motivation (n = 142), interest in using ONPs to quit/reduce vaping (44.4%) was higher than interest in using medicinal nicotine gum/lozenges (23.4%), nicotine patch (17.6%), or prescription medications (16.6%). Interest in using ONPs to reduce/quit vaping (vs. no interest) was greater among participants who reported vaping ≥20 (vs.

BACKGROUND: Tobacco users with mental health conditions are a vulnerable population in tobacco research, yet few studies have evaluated the association of depressive and anxiety symptoms with multiple tobacco product (MTP) use among young adult electronic cigarette (ENDS) users. METHODS: Cross-sectional survey data on U.S. young adult past 30-day ENDS users (N = 2348) were collected via Amazon MTurk from May-July 2019. Binary logistic regressions evaluated the association of tobacco use pattern (exclusive ENDS use, ENDS + one other tobacco product [OTP; dual use], ENDS + two or more OTPs [poly-use]) with depressive (PHQ-9) and anxiety (GAD-7) symptoms. Among MTP users (n = 1736), we evaluated the association of ENDS use relative to OTP use and same-day MTP use with depressive and anxiety symptoms. RESULTS: The sample included 26% exclusive ENDS, 27% dual, and 47% poly-users. We observed a gradient-relationship for depressive and anxiety symptoms: poly-users had greater odds of depressive and anxiety symptoms compared to dual users (aOR = 1.86 [95%CI:1.50–2.30] and aOR = 1.61 [95%CI:1.30–2.01], respectively), and dual users had greater odds of depressive and anxiety symptoms compared to exclusive ENDS users (aOR = 1.42 [95%CI:1.11–1.81] and aOR = 1.56 [95%CI:1.20–2.02], respectively). MTP users who used ENDS more often than OTPs (vs. less often than OTPs) had greater odds of depressive (aOR = 1.38 [95%CI:1.06–1.80]) and anxiety (aOR = 1.37 [95%CI:1.04–1.79]) symptoms. CONCLUSIONS: The majority of young adult past 30-day ENDS users in this sample reported OTP use. Future research on MTP use should distinguish between dual and poly-use. Tobacco prevention efforts for young adults with mental health symptoms are needed.

Background‘Ice’ e-cigarette flavours—marketed as a combination of fruity/sweet and cooling flavours (eg, ‘blueberry ice’ or ‘melon ice’)—recently entered the US market. The prevalence and correlates of ice flavoured e-cigarette use in young adults are unknown.MethodsThis cross-sectional study of a Los Angeles, California, USA, cohort analysed data from the past 30-day e-cigarette (current) users (n=344; M (SD)=21.2 (0.4) years old) who completed web-based surveys from May–August 2020. The exposure variable was self-reported e-cigarette flavour used most often in the past month (menthol/mint, fruit/sweet or ice). Outcomes included self-reported combustible tobacco use, vaping dependence symptoms, frequency of use and device type used.ResultsAmong current e-cigarette users, 48.8% reported using ice flavours most often, 33.7% predominately used fruit/sweet and 17.4% used menthol/mint. Using primarily ice-flavour was associated with reporting more past-30-day vaping days (vs menthol/mint: b=4.4, 95% CI (1 to 7.7); vs fruit/sweet: b=3.6, 95% CI (0.8 to 6.4)) and more episodes per vaping day versus fruit/sweet users (b=2.4, 95% CI (0.5 to 4.3)). Ice-flavour users were less likely than menthol/mint users to use JUUL/cartridge-based rechargeable (OR=0.1, 95% CI (0.03 to 0.45)) and more likely than sweet/fruit users to use disposable non-cartridge (OR=3.9, 95% CI (2.1 to 7.4)) devices than refillable/rechargeable tank/pen or other devices. Ice users had greater odds of past 30-day combustible tobacco use versus menthol/mint users (OR=2.7, 95% CI (1.3 to 5.7)) and vaping dependence symptoms than versus sweet/fruit users (OR=2.6, 95% CI (1.5 to 4.4)).ConclusionYoung adult use of ice flavoured e-cigarettes may be common and positively associated with combustible tobacco use, nicotine vaping frequency and dependence and use of disposable e-cigarette devices. Further study of the prevalence, determinants and health effects of ice flavoured e-cigarette use is warranted.

BACKGROUND AND OBJECTIVES Flavored non-tobacco oral nicotine products (eg, nicotine pouches and nontherapeutic nicotine gum, lozenges, tablets, gummies), are increasingly marketed in the United States. Prevalence of non-tobacco oral nicotine product use among adolescents is unknown. METHODS We calculated prevalence of ever and past 6-month use of nicotine pouches, other non-tobacco oral nicotine products (ie, gum, lozenges, tablets, and/or gummies), e-cigarettes, cigarettes, hookah or waterpipe, cigars, cigarillos, and snus among high school students in Southern California between September and December 2021. Generalized linear mixed models tested associations of sociodemographic factors and tobacco-product use with use of any non-tobacco oral nicotine product. RESULTS Among the sample (n = 3516), prevalence was highest for e-cigarettes (ever: 9.6%, past 6-month: 5.5%), followed by non-tobacco oral nicotine products (ever: 3.4%, past 6-month: 1.7%), and CONCLUSIONS Non-tobacco oral nicotine products were the second most prevalent nicotine product used by adolescents. They were disproportionately used by certain racial or ethnic, sexual, or gender minority groups, and those with a history of nicotine use. Adolescent non-tobacco oral nicotine product use surveillance should be a public health priority.

INTRODUCTION: In observational studies, vaping daily is positively associated with cigarette smoking abstinence, while non-daily vaping is associated with less smoking abstinence (versus no e-cigarette use). It remains unknown whether cigarette smokers who vape daily have different motivations for using e-cigarettes than those who vape non-daily. METHODS: Using latent class analysis and 10 self-reported reasons for vaping, we identified sub-groups of participants based on vaping motivations among 1544 adult (≥18 y) dual users of e-cigarettes and cigarettes at wave 4 of the Population Assessment of Tobacco and Health (2016–2018). We examined the association of motivation sub-groups with vaping frequency at wave 4, and subsequent cigarette smoking abstinence at wave 5 (2018–2019). Additional analyses examined the association of vaping frequency with smoking abstinence before and after adjustment for motivation sub-groups. RESULTS: Four distinct sub-groups of e-cigarette users emerged, including 54 % of participants who were “Vaping Enthusiasts”, 20 % who vaped for “Convenience and Social Acceptability”, 10 % classified as “Experimenters” and 16 % who vaped for “Quitting Smoking and Harm Reduction.” The Convenience and Social Acceptability sub-group were less likely than “Vaping Enthusiasts” (AOR=0.29, 95 %CI[0.20–0.42]) and “Quitting Smoking and Harm Reduction” (AOR=0.41, 95 %CI[0.24–0.71]) classes to vape daily (versus non-daily). Sub-groups were not associated with smoking abstinence after one year. Adjustment for motivation sub-groups did not attenuate a positive association of daily vaping with smoking abstinence. CONCLUSIONS: Cigarette smokers who vaped for convenience and social acceptability were less frequent e-cigarette users than those with other vaping motivations. Vaping motivations were not associated with subsequent smoking abstinence.

This cross-sectional study examines differences by race and ethnicity and education in smoking prevalence and age of smoking initiation among young adults in the US between 2002 and 2019.

Laboratory research in adults indicates that alcohol-related subjective effects are enhanced under some social conditions. However, it is unknown whether this “social facilitation” of alcohol effects occurs in adolescents and is associated with alcohol use in the natural ecology. We examined associations of social facilitation of alcohol-related subjective effects with subsequent alcohol use among a relatively high-risk group of adolescents who reported drinking alcohol both with friends and alone. Los Angeles high school students from a prospective study (N = 142; 51% female; 10th graders) completed a baseline survey that assessed alcohol-related “positive” and “negative” subjective effects in two contexts: social (alcohol with friends) and solitary (alcohol alone); social facilitation was calculated as the difference between social and solitary. Students then completed five semi-annual surveys spanning 30 months (2014–2017) assessing 30-day alcohol use (days used, number of drinks, binge drinking). Greater social facilitation of positive effects was significantly associated with greater number of alcohol use days (RR [95% CI] = 1.48 [1.19, 1.82]; p

PURPOSE: New oral nicotine products (ONPs), often advertised as “tobacco-free” (i.e., pouches, gum, lozenges, gummies), come in nontobacco flavors appealing to adolescents. It is unknown how adolescent willingness to use ONPs differs by product type and flavor, and whether sociodemographic disparities exist. METHODS: Adolescent never tobacco product users (n = 1, 289) in ninth or 10th grade from 11 high schools in Southern California were surveyed in fall 2021 about ever and past 6-month use of ONPs and sociodemographic characteristics. Adolescents were randomized to view five different ONPs in either fruit or mint flavor, and asked to rate their willingness to use each product. Multivariable logistic random effect-repeated measures regression examined associations of product type, flavor, and sociodemographic characteristics with any willingness to use ONPs. RESULTS: Compared to traditional smokeless tobacco (willingness = 17.8%), adolescents reported greater willingness to use ONPs (gum, 28.2%; pouches, 21.1%; lozenge, 22.4%; gummies, 24.1%); adjusted odd ratios [aORs] 1.25–1.84; p-values

Introduction The rapidly evolving landscape of vaping devices has complicated analyses of use patterns among youth and young adults. The current study describes the prevalence of use, substances vaped, and purchasing behaviors across five different vaping device categories. Aims and Methods Participants (n = 2505; mean age = 19.2, SD = 0.46) from a cohort in the Los Angeles area completed web-based surveys from June 2018 to October 2019. For each of four device type categories depicted via digital images (any pod-style vape, cigalike, box-mod, vape pen) and for JUUL specifically, participants reported ever and past 30-day use, substance vaped (mostly nicotine, nicotine and tetrahydrocannabinol [THC], mostly THC, neither), ownership of device (yes/no), where they obtained that device (eg, purchased themselves, from a friend), and if purchased, purchase location (eg, vape shop, online). Results Overall, 44.9% reported ever use, and 26.2% reported past 30-day use of at least one of the devices. The prevalence of past 30-day use was highest for pod-style vapes (any pod = 17.0%; JUUL = 15.1%). Among respondents who reported ever owning any device (n = 643 [25.7%]), 59.9% reported purchasing the device themselves, despite not being of legal purchasing age (15.4% of total sample); across all device types, products were most often purchased in vape shops or online. Conclusions Across all devices, the prevalence of self-purchase of vaping devices among underage young adults in the Los Angeles area was high, and most were purchased from a vape shop or online. Tobacco control policies to prevent underage purchase of tobacco products—particularly among never smokers—are needed. Implications A high proportion of underage young adults reported owning their own vaping device and having purchased it themselves from a vape shop or online. Stronger tobacco control policies and better enforcement efforts are needed to successfully prevent underage purchase of tobacco products.

IntroductionCigarette use is declining yet remains common among adults with mental health conditions. In contrast, e-cigarette use may be on the rise. This study investigated the relationship between serious psychological distress (SPD) and the exclusive and dual use of cigarettes and e-cigarettes among US adults from 2014 to 2017.Aims and MethodsData came from 2014 to 2017 National Health Interview Survey, an annual, cross-sectional survey of nationally representative samples of US adults (total combined analytic sample n = 125 302). Past-month SPD was assessed using the Kessler Psychological Distress Scale (K6) and cigarette and e-cigarette use were assessed at each wave. Logistic regressions examined product use by SPD status in 2017 and trends in product use by SPD status from 2014 to 2017. Analyses adjusted for demographic covariates.ResultsThe prevalence of cigarette use, e-cigarette use, and dual use was higher among adults with SPD than without SPD in each year including the most recent data year 2017 (cigarette use, 39.50% vs. 13.40%, p < .001; e-cigarette use, 7.41% vs. 2.65%, p < .001; dual use, 5.30% vs. 1.26%, p < .001). Among adults with SPD, the prevalence of cigarette, e-cigarette, and dual product use did not change from 2014 to 2017 in contrast to a decreasing prevalence in cigarette, e-cigarette, and dual product use among individuals without SPD.ConclusionsUS adults with SPD report higher levels of cigarette, e-cigarette, and dual product use than adults without SPD. Use of these products has not declined over the past several years in contrast to decreasing trends among adults without SPD.ImplicationsThese data extend our knowledge of tobacco product use and mental health disparities by showing that in addition to higher levels of cigarette use, US adults with SPD also use e-cigarettes and dual products (cigarette and e-cigarette) more commonly than those without SPD. Furthermore, the use of these products has not declined over the past several years in contrast to continuing declines among adults without SPD. More research is needed to understand the potential positive and negative consequences of e-cigarette use among adults with SPD.

BackgroundTobacco 21 (T21) laws, which raise the minimum legal age of sale of tobacco products to 21, have been proposed and implemented in states and cities across the USA. However, limited data are available on the effect of T21 laws on youth tobacco purchasing behaviours and access to tobacco products.MethodsParticipants in a population-based prospective cohort in southern California completed questionnaires before (n=1609, age=18–19 y) and after (n=1502, age=19–20 y) T21 was implemented in California (June 2016). We examined the prevalence of past 30-day cigarette and e-cigarette use, and among past 30-day users, purchase location of tobacco products before (pre-) versus after (post-) T21. We also examined whether, post-T21, participants were refused purchase of tobacco products due to their age, and the perceived relative ease of purchasing cigarettes and e-cigarettes (vs pre-T21).ResultsNegligible changes in cigarette and e-cigarette use were observed pre-T21 versus post-T21. At both time points, the majority of past 30-day users purchased cigarettes from gas stations and e-cigarettes from vape shops. Post-T21, the proportion of participants who reported purchasing cigarettes at gas stations decreased. Post-T21, most past 30-day cigarette or e-cigarette users were not refused purchase of cigarettes (65.4%) or e-cigarettes (82.0%) in the past 30 days, despite being under 21; half of the participants felt it was harder to purchase cigarettes (54.3%) and e-cigarettes (43.6%) post-T21.ConclusionPost-T21, few participants were refused purchase of any tobacco product, despite the illegality of such sales. Better enforcement of T21 is needed to improve the efficacy of T21 legislation.

Introduction E-cigarette studies have found that the use of a variety of flavors and customizable devices results in greater use frequency and user satisfaction. However, standardized research e-cigarettes are being developed as closed systems with limited flavor options, potentially limiting user satisfaction. In this study, we explore protocol compliance in an e-cigarette study using a standardized, assigned device with puff time and duration tracking (controlled e-cigarette) and potential limitations that controlled devices and e-liquids can introduce. Methods In a crossover study, 49 young adult e-cigarette users were recruited using convenience sampling and assigned a controlled e-cigarette device and flavored or unflavored e-liquids on standardized protocols. E-cigarette use frequency (number of puffs per day, collected from the device) and serum cotinine levels were obtained at each of three study visits over 3 weeks. The correlation of cotinine and e-cigarette use over the preceding week was calculated at each study visit. Results Correlation of nicotine intake, as measured by serum cotinine, and puff time, as measured by puffs count and duration from the e-cigarette device, as an indicator of study protocol compliance, substantially declined after the first week of the study and were no longer correlated in the remaining study weeks (R2 = 0.53 and p ≤ .01 in week 1, R2 < 0.5 and p > .05 for remaining weeks). Conclusions There is an emerging need for controlled e-cigarette exposures studies, but low compliance in the use of assigned devices and e-liquids may be a limitation that needs to be mitigated in future studies. Implications This study is the first to analyze compliance with instructions to use a standardized e-cigarette device with puff time and duration tracking (controlled e-cigarette) across all subjects and an assigned e-liquid flavor over a 3-week period. We find that protocol compliance, as measured by correlations between e-cigarette use measures and cotinine levels, was only achieved in the first week of the study and declined thereafter. These findings indicate that the assignment of a study device and instruction to only use the study device with assigned e-liquid flavor may not be sufficient to ensure participant compliance with the study protocol. We suggest that additional measures, including behavioral and biological markers, are needed to ensure sole use of the study e-cigarette and e-liquid and to be able to interpret results from controlled e-cigarette studies.

Introduction Previous studies suggest that young adults who vape nicotine experience difficulty when answering survey items assessing the quantity of vaping. The current study asked young adults who vape to provide suggestions for improving the scientific measurement of vaping. Aims and Methods We conducted semi-structured qualitative interviews with 62 young adults who vape in Los Angeles, California between June 2018 and June 2019. We analyzed participants' responses to the following question: “What do you think is the best way for us to understand how much people vape?” using thematic content analysis. Results We identified two major themes: (1) challenges stemming from differences between the way researchers query about vaping and how individuals self-monitor vaping frequency, and (2) insights for future measurement of vaping. Participants reported that challenges of accurately quantifying vaping were due to inherently hard-to-answer questions (eg, puffs per day), lack of awareness of or not actively monitoring consumption of vaping products, or because vaping behaviors vary considerably between and within individuals over time, making “on-average” questions challenging. Participants discussed ideas for improving survey measures that could accurately assess vaping quantity, including querying about the type of device used, and frequency of replenishment of nicotine solutions. Conclusions Existing vaping behavior survey measures may not accurately capture the quantity of vaping as they differ from how (or if) participants track their own vaping consumption patterns. While continued research is needed to optimally refine survey measures on vaping consumption, future measures may better align with vapers' self-monitoring by including questions on device-type and replenishment frequency. Implications The present study provides insights regarding the variability that exists between vaping quantity measurements utilized by researchers and individuals who consume e-cigarettes. The qualitative data analyzed for this study support previous reports of difficulties faced by vapers when asked questions by researchers related to their vaping behavior. Furthermore, the present findings suggest the direction for the future development of accurate measurements of vaping frequency.

Emerging research has found that some young adults report vaping nicotine to control appetite and lose weight. Yet, there is little research on how young adults use vaping to manage weight, where they learn about weight-motivated vaping, and the role that food and weight motivations play in decisions to vape.We conducted one-on-one qualitative interviews with young adults aged 18-25 years old in Los Angeles, California (N = 62) from June 2018 to June 2019, who self-reported using e-cigarettes on a weekly basis or more for at least 5 months prior to study enrollment. Interviews examined participants' thoughts, feelings, and experiences related to e-cigarette use, including their understanding of the relation of vaping with eating behaviors and weight management. We analyzed the interviews using the rigorous and accelerated data reduction (RADaR) technique.Participants reported pairing nicotine vaping with caffeinated beverages like coffee, pop/soda, tea, and after every meal (like patterns of combustible cigarette use). Participants also reported vaping nicotine as a tool to avoid binge eating and increase concentration while studying. Reports of vaping effecting appetite and eating behaviors also emerged. Vaping nicotine to suppress appetite and/or achieve weight loss was often reported in conjunction with an eating disorder. Participants reported learning about weight-motivated vaping from peers or deducing from cigarette effects and their own experiences with nicotine. Others mentioned controlling food cravings by vaping a similar e-liquid flavor.Nicotine vaping was used as a tool to control weight and suppress appetite, paralleling food- and weight-related behaviors associated with cigarette use. Findings suggest a need for targeted interventions that address the role of nicotine vaping in eating/weight-related behaviors.

Adverse childhood experiences (ACE) have a strong association with alcohol and drug use; however, more research is needed to identify protective factors for this association. The present study assesses the longitudinal impact of ACE on problematic alcohol and drug use and the potential moderating effect of perceived social support. Data (n = 1404) are from a sample of Hispanic youth surveyed in high school through young adulthood. Linear growth curve models assessed the effect of ACE and perceived social support over time on problematic alcohol and drug use. Results indicated youth with ACE (vs. those without ACE) report more problematic alcohol and drug use in adolescence and have increased rates into young adulthood. Additionally, findings suggest that social support in high school may moderate the effects of ACE on problematic use over time. Among youth with high levels of support, the association of ACE with problematic alcohol and drug use was diminished. Although ACE can have a persistent impact on problematic alcohol and drug use from adolescence into adulthood, high social support during adolescence may mitigate the negative effects of ACE, lowering early problematic alcohol and drug use, offering the potential for lasting benefits.

Non-therapeutic, novel oral nicotine products are convenient, discreet to use, and flavored, with increasing sales in the United States. It is unclear whether these products appeal predominantly to adolescents already susceptible to inhalable nicotine products, or whether they attract adolescents who would not otherwise use nicotine. This study examined prevalence and correlates of susceptibility to inhalable and oral nicotine product use among adolescents. Ninth- and tenth-grade students from Southern California who had never used any nicotine product (N = 3129) completed an online survey in Fall 2021 assessing susceptibility to inhalable (i.e., cigarettes, e-cigarettes) and oral (e.g., pouches, gum, gummies) nicotine products. Multinomial logistic regression analyses estimated associations of demographic characteristics with odds of susceptibility to oral, inhalable, or both products. Susceptibility was highest for e-cigarettes (19.7%), followed by cigarettes (15.0%) and nicotine gum, lozenges, tablets and/or gummies (15.0%), and nicotine pouches (8.7%). Dual susceptibility to oral and inhalable products (vs. neither product type) was higher in cisgender female and non-cisgender (vs. cisgender male) adolescents (odds ratios [ORs] = 1.36-2.02; ps 0.05). Hispanic adolescents (vs. Asian) were more susceptible to both products (OR = 1.47; p .05). Lower-socioeconomic status (SES) and sexual minority adolescents were more susceptible to oral (ORs = 1.76-1.87; ps 0.05) and both products (ORs = 1.32-1.88; ps 0.05), compared to higher-SES and heterosexual adolescents. Adolescents in Southern California may be more susceptible to e-cigarettes than other nicotine/tobacco products. However, appreciable numbers may be susceptible to oral nicotine products, including some youth who might not otherwise use nicotine and youth from populations historically impacted by tobacco-related health disparities.

Introduction Cannabis—including blunts (cannabis rolled in tobacco-containing cigar casing) —is commonly the first substance used among adolescents and may increase the likelihood of subsequent initiation of combustible tobacco products. Aims and Methods Data were pooled from two prospective studies of adolescents in California and Connecticut (total N = 4594). Logistic regression models assessed the association of baseline ever blunt use and ever non-blunt cannabis use (vs. never cannabis use) with subsequent initiation of any combustible tobacco-only product (ie, cigarettes, cigars, or cigarillos) by 1-year follow-up after adjustment for demographic characteristics and other tobacco product use at baseline. We also assessed whether estimates differed by prior e-cigarette or hookah use at baseline. Results Among never combustible tobacco-only product users (N = 2973), 221 (7.4%) had ever used a blunt and 114 (3.8%) had ever used only non-blunt cannabis at baseline. Blunt use (adjusted odds ratio [AOR] = 1.98, 95% confidence interval [CI]: 1.30 to 3.01) and non-blunt cannabis use (AOR = 2.38, 95% CI: 1.41 to 4.00) were independently associated with greater odds of combustible tobacco-only product initiation by follow-up. Among those who had not tried e-cigarettes or who had not tried hookah, blunt use and non-blunt cannabis use were associated with significantly increased odds of combustible tobacco product initiation; among those who had tried e-cigarettes or hookah, the association was not significant. Conclusions We found blunt and non-blunt cannabis use to be associated with subsequent combustible tobacco-only product initiation, particularly among adolescents who had not also tried other products containing nicotine. Implications Adolescent-focused tobacco prevention efforts should consider incorporating cannabis products, including blunts. More research is needed to understand how blunt use and cannabis use more broadly are associated with initiation of tobacco products.

To estimate the association of longitudinal patterns of e-cigarette use with cigarette smoking abstinence, after accounting for time-dependent confounding and selection bias.Secondary analysis of longitudinal national cohort data. Using marginal structural models and four waves of the population assessment of tobacco and health (wave 1, 2013-14; wave 2, 2014-15; wave 3, 2015-16; wave 4, 2016-18), we estimated the association of vaping frequency across waves 2 and 3 with 12-month sustained cigarette smoking abstinence at wave 4, adjusting for time-dependent confounders at waves 1 and 2 and selection bias due to drop-out with inverse probability of treatment and censoring weights.United States.A total of 5699 adults (18+ years) who smoked cigarettes and did not vape at wave 1.The exposure was vaping frequency at waves 2 and 3 (non-use, non-daily use, daily use), representing nine possible combinations of vaping frequency across two waves. Non-use at both waves was the exposure reference group. The primary outcome was sustained 12-month cigarette smoking abstinence at wave 4.Among 5699 adults who smoked cigarettes at wave 1, a total of 560 (9.8%) reported smoking abstinence at wave 4. Compared with nonuse at both waves, daily vaping at both waves [risk ratio (RR) = 3.82, 95% confidence interval (CI) = 2.59-5.64] and non-use at wave 2 followed by daily vaping at wave 3 (RR = 2.50, 95% CI = 1.66-3.77) were positively associated with smoking abstinence; non-daily vaping at both waves was inversely associated with smoking abstinence (RR = 0.28, 95% CI = 0.11-0.75). Results persisted after accounting for misclassification of e-cigarette use and cigarette smoking abstinence and after restricting to participants with plans to quit smoking.In a US cohort of adult smokers, longitudinal patterns of vaping frequency appear to predict smoking abstinence, even after accounting for several sources of systematic error. Consistent daily vaping is associated with increased chances of cigarette smoking abstinence, while consistent non-daily vaping is associated with decreased chances of smoking abstinence.

Introduction Machine learning presents a unique opportunity to improve electronic cigarette (vaping) monitoring in youth. Here we built a random forest model to predict frequent vaping status among Californian youth and to identify contributing factors and vulnerable populations. Methods In this prospective cohort study, 1281 ever-vaping twelfth-grade students from metropolitan Los Angeles were surveyed in Fall and in 6-month in Spring. Frequent vaping was measured at the 6-month follow-up as nicotine-containing vaping on 20 or more days in past 30 days. Predictors (n = 131) encompassed sociodemographic characteristics, substance use and perceptions, health status, and characteristics of the household, school, and neighborhood. A random forest was developed to identify the top ten predictors of frequent vaping and interactions by sociodemographic variables. Results Forty participants (3.1%) reported frequent vaping at the follow-up. The random forest outperformed a logistic regression model in prediction (C-Index = 0.87 vs. 0.77). Higher past-month nicotine concentration in vape, more daily vaping sessions, and greater nicotine dependence were the top three of the ten most important predictors of frequent vaping. Interactions were found between age and perceived discrimination, and between age and race/ethnicity, as those who were younger than their classmates and either reported experiencing discrimination frequently or identified as Asian or Native American/Pacific Islander were at increased risk of becoming frequent vapers. Conclusions Machine learning can produce models that accurately predict progression of vaping behaviors among youth. The potential association between frequent vaping and perceived discrimination warrants more in-depth analyses to confirm if discrimination constitutes a cause of increased vaping. Implications This study demonstrates the utility of machine learning in predicting status of frequent vaping over 6 months and understanding predictors and nuanced intersectionality by sociodemographic attributes. The high performance of the random forest model has practical implications for a personalized risk calculator that supports vaping prevention program. Public health officials need to recognize the importance of social factors that contribute to frequent vaping, particularly perceived discrimination. Youth subpopulations, including younger high school students and Asians or Native Americans/Pacific Islanders, might require specially designed interventions to help prevent habit-forming in vaping.

E-cigarette use among adolescents and young adults has been associated with adverse respiratory symptoms, including symptoms of asthma and bronchitis. This investigation examined whether such associations differ by primary type of e-cigarette device used. This cross-sectional study included data from four study populations in California and Connecticut, United States, ages 13-21years (N=10,483), who self-reported their tobacco use behaviors and health status from 2018 to 2020. Adverse respiratory symptoms were grouped as bronchitis, asthma exacerbation, and shortness of breath. Associations with e-cigarette use were examined by frequency of e-cigarette use (regardless of device type) and most-frequently use device type in the past 30days (pod, pen/tank, disposable, or mod). Multivariable modeling accounted for demographic variables and use of other tobacco and cannabis. Results were pooled at the study level via random-effects meta-analysis. Across the four studies, e-cigarette use >5days/month versus never use was associated with bronchitic symptoms (summary odds ratio, sOR: 1.56; 95% confidence interval, CI: 1.37, 1.77) and shortness of breath (sOR: 1.68; 95% CI: 1.35, 2.08) but not statistically significantly with asthma exacerbations (sOR: 1.36; 95% CI; 0.95, 1.95). Among past 30-day e-cigarette users, associations with respiratory symptoms did not differ by device type. In these populations, e-cigarette use was positively associated with symptoms of bronchitis and shortness of breath, but adjusted odds of symptoms did not differ meaningfully by device type. These findings suggest that risk of these respiratory outcomes is elevated among more frequent e-cigarette users regardless of device type used.

COVID-19 vaccines have been available for over a year, yet 26% of U.S. young adults remain unvaccinated. This study examines racial and ethnic disparities in young adult vaccine hesitancy and attitudes/beliefs that mediate disparities in vaccine hesitancy. Young adults (n = 2041;Mean[SD]:21.3[0.7] years-old) from a Los Angeles, CA, USA cohort were surveyed online in January-May 2021 and classified as vaccine hesitant (those who reported "Not at all likely"/"Not very likely" /"Slightly likely" to get vaccinated) versus non-hesitant (those who reported "Moderately likely"/"Very likely"/"Definitely likely" to get vaccinated or already vaccinated). Multivariable logistic regression was performed to examine racial/ethnic disparities in vaccine hesitancy. Factor analysis was conducted to create three subscales toward vaccination: positive, negative, and lack-of-access beliefs. Mediation analyses were performed to assess pathways from attitude/belief subscales to racial disparities in vaccine hesitancy. Overall 33.0% of respondents reported vaccine hesitancy. Black vs. White young adults had a higher prevalence of vaccine hesitancy (AOR[95%CI] = 4.3[2.4-7.8]), and Asians vs. Whites had a lower prevalence (AOR[95%CI] = 0.5[0.3-0.8]). Mediators explained 90% of the Black (vs. White) disparity in vaccine hesitancy, including significant indirect effects through positive belief-reducing (β = 0.23,p .001) and negative belief-enhancing (β = 0.02,p = .04) effects. About 81% of the Asian (vs. White) disparity in vaccine hesitancy was explained by the three combined subscales, including significant positive belief-reducing (β = -0.18,p .001) indirect effect. Substantial racial and ethnic disparities in young adult COVID-19 vaccine hesitancy were found, which were mediated by differences in attitudes and beliefs toward vaccination. Targeted education campaigns and messages are needed to promote equitable utilization of the effective vaccine.

BACKGROUND Adolescent nonmedical prescription opioid use is associated with overdose and other adverse outcomes, but its risk factors are poorly understood. METHODS Data were drawn from a prospective cohort study of Los Angeles, California, high school students. At baseline (mean age = 14.6 years), students completed self-report screening measures of problem alcohol, cannabis, and drug use and 6 mental health problems (major depression, generalized anxiety, panic disorder, social phobia, obsessive-compulsive disorder, and hypomania or mania). Past 6-month nonmedical prescription opioid use (yes or no) was assessed across 7 semiannual follow-ups. RESULTS Among baseline never users of nonmedical prescription opioids (N = 3204), average past 6-month prevalence of new nonmedical prescription opioid use across the 42-month follow-up was 4.4% (range 3.5%–6.1%). In a multivariable model co-adjusting for 9 baseline behavioral problems and other factors, major depression, hypomania or mania, cannabis, alcohol, and other drug use problems were associated with increased odds of nonmedical prescription opioid use over follow-ups. Cumulative indices of behavioral health comorbidity showed successively greater odds of subsequent nonmedical prescription opioid use for students with 1 (odds ratio [OR]: 3.74; 95% confidence interval [CI]: 2.79–5.01), 2 (OR: 8.79; 95% CI: 5.95–12.99), or 3 (OR: 9.69; 95% CI: 5.63–16.68) vs 0 baseline substance use problems, and similar increases were associated with increasing number of mental health problems (1 [OR: 1.60; 95% CI: 1.03–2.88] to all 6 [OR: 3.98; 95% CI: 1.09–14.82] vs 0). CONCLUSIONS Behavioral health problems may be associated with increased risk of subsequent nonmedical prescription opioid use during mid to late adolescence, with successively greater risk for those with greater behavioral health comorbidity. In pediatric clinical practice or school-based prevention, behavioral health screeners may be useful for identifying youth at high risk for nonmedical prescription opioid use.

This Viewpoint discusses a federal policy loophole that allows psychotropic cannabis products to be commercially marketed and sold across the US, even in states where recreational cannabis is not legal.

Introduction Type of e-cigarette flavoring and device during first use might differentiate later e-cigarette use and dependence. This retrospective cross-sectional study examined associations of recalled first nicotine vaping device and flavor used with current vaping frequency/dependence. Aims and Methods A young adult cohort from Los Angeles, California, USA completed web-based surveys (N = 2553). Using cross-sectional data from 971 reporting ever vaping nicotine, multivariable hurdle regressions tested associations between recalled first flavor (fruit/sweet, menthol/mint, other) and device (Juul, disposable, mod, box, pod, pen, other) vaped with past-30-day vaping status (yes/no) and frequency (1–30 days), and with any vaping dependence symptoms (yes/no) and count (1–10 symptoms). Results The most common first-flavor was sweet (71%); the most common first-device was a vape pen (37%), then Juul (22%). First-flavor of mint/menthol (vs. other; adjusted odds ratio [AOR]: 2.22[95% CI = 1.16 to 4.25]), and first-device mod (AOR = 2.40[95% CI = 1.34 to 4.31]) and non-Juul pod (2.64[95% CI = 1.41 to 4.92]) (vs. pen) were associated with past-30-day vaping, and twice as many vaping days (adjusted rate ratios [ARRs] range: 1.96–2.12; ps < .05). First flavor of mint/menthol (vs. other; AOR: 1.95[95% CI = 1.003 to 3.79) and first device mod, box, non-Juul pod, and other (AORs range: 2.36–4.01; ps < .05) were associated with nicotine dependence. First device Juul, mod, box, and non-Juul pod were also associated with more dependence symptoms (ARRs range:1.38–1.59; ps < .05). Conclusions Exposure to mint/menthol and certain devices (mod, box, Juul, and non-Juul pods) at first e-cigarette use may be associated with more frequent e-cigarette use and nicotine dependence symptoms in young adulthood. Mint/menthol and certain devices warrant consideration in regulation of e-cigarettes based on product characteristics. Implications Characteristics (flavor and device type) of first e-cigarette product used were associated with higher usage and more dependence. Pending replication with prospective designs, the findings suggest certain flavors (mint/menthol) and devices (pods, mods) merit consideration in regulation because of their possible link with continued use and dependence among young people.

Introduction Young adult never-smokers who vape are at elevated risk of initiating cigarettes, while young adults who smoke often begin vaping to substitute or reduce cigarette use. Reasons underlying different use patterns of tobacco products are not well-understood. Aims and Methods We conducted 1-on-1 qualitative interviews with young adults (N = 62) who vape in Los Angeles, California from June 2018 to June 2019. Participants were 18–25 years old (79% male; racially/ethnically diverse) and self-reported vaping ≥1x/week. We used a semi-structured interview guide and applied thematic analysis method to analyze data. Results Young adults initiated vaping due to peer socialization and e-liquid flavor novelty. They often reported vaping (after first smoking) due to a belief that e-cigarettes are healthier, social pressure to quit smoking, and convenience of use. Participants reported smoking (after first vaping) when traveling outside of the United States where vaping products were less accessible, and cigarettes were normative. Many of the personal narratives described patterns of dual and cyclical use, which was often attributed to nicotine dependence and cost, or described as dependent upon the current environment (eg, at a party). Conclusions The current study characterizes nicotine use trajectories and reasons why young adults vape, and smoke cigarettes. Dual and cyclical use of both e-cigarettes and cigarettes was common; this pattern of use should be considered in policy and prevention work to address nicotine dependence among young people. Implications We display findings from the current study in a model depicting common trajectories of nicotine use, along with reasons for initiation, transitions between products, and dual/cyclical e-cigarette and combustible cigarette use.

Research exploring patterns and predictors of problematic cannabis use behaviors among young adults is limited. This knowledge is essential for intervening to prevent abuse and dependence outcomes. METHODS: Young adult cannabis users (Mage=19.2[SD=0.8]) in Southern California (N=1007) were classified by patterns of problematic cannabis use from the Cannabis Abuse Screening Test, using Latent Class Analysis. Multinomial regression evaluated the association of frequency of use (no past 30 day use, infrequent [use on 1-2 of past 30 days], semi-frequent [use on 3-9 of the past 30 days], and frequent [use on 10 or more of the past 30 days]) for each cannabis product type (combustible, edible, vaporized, concentrate, blunt) with class membership. RESULTS: Four distinct classes of cannabis-related problems were identified: “non-symptomatic” (no problems; 33.8%), “non-recreational use” (before noon and when alone; 34.5%), “moderate use problems” (before noon, alone, and memory problems; 8.0%), and “severe cannabis problems” (all 6 problems; 23.7%). Semi-frequent (AOR range: 1.85-4.63;ps

Introduction Novel, inexpensive disposable e-cigarettes widely sold in attractive flavors might be exempt from US federal regulations. To inform regulatory and public health priorities, this study examined young adult disposable e-cigarette use uptake among existing tobacco users versus non-users and possible use correlates that could be potential regulatory targets. Aims and Methods Prospective cohort data were analyzed in 2021. Among baseline (2018–2019) never disposable e-cigarette users (n = 1903; mean [SD]: 19.3 [0.8] years-old), we tested prospective associations of baseline tobacco product use with follow-up (2020) disposable e-cigarette use initiation, followed by stratified analyses distinguishing baseline exclusive and dual e-cigarette/combustible tobacco use. Exploratory cross-sectional associations of tobacco-related correlate with vaping frequency among current disposable users (n = 266) were tested. Results Follow-up ever disposable e-cigarette use initiation was higher among baseline former (22.1%) and current (50.2%) versus never (6.3%) rechargeable (non-disposable) e-cigarette users. In stratified analyses, follow-up disposable e-cigarette use initiation was 0% in baseline never-vaping exclusive current smokers, higher in baseline never-vaping former smokers versus never users of any tobacco product (18.2% vs. 5.7%; adjusted odds ratio [95% CI] = 3.9 [2.1–7.5]), and higher among baseline current dual users versus never-smoking exclusive current vapers (61.3% vs. 42.2%; adjusted odds ratio [95% CI] = 3.0 [1.5–6.0]). Among follow-up current disposable e-cigarette users (overall prevalence = 10.9%), using ice-flavored (vs. fruit/sweet-flavored) e-cigarettes (adjusted rate ratio [95% CI] = 1.5 [1.0–2.1]) and vaping dependence symptoms (adjusted rate ratio [95% CI] = 2.2 [1.5–3.2]) were cross-sectionally associated with more past-month disposable e-cigarette use days. Conclusions Young adult disposable e-cigarette use was of appreciable prevalence, including among tobacco product never users and former smokers. Regulation of disposable e-cigarettes, including ice-flavored products, might benefit young adult health. Implications Sales of disposable e-cigarette products increased significantly in the United States from 2019 to 2020. These products contain high nicotine concentrations and various flavors that may appeal to young people. This study provides the first evidence that disposable e-cigarette use may be common among young adults, including among tobacco product never users and former smokers. Frequency of disposable e-cigarette use was positively associated with using ice-flavored e-cigarettes and vaping dependence. Regulatory policies and enforcement strategies addressing disposable e-cigarettes merit consideration in young adult health policy and prevention priorities.

Background The “cigarette susceptibility index” has been adapted for other products, yet, the validity of these adapted measures–particularly among youth who have used other tobacco products–has not been evaluated. Methods We used prospective data from the Southern California Children's Health Study to evaluate the association of questionnaire measures assessing susceptibility to e-cigarette, cigarette, hookah and cigar/cigarillo/little cigar use at wave 1 (W1; 11th/12th grade) with subsequent initiation between W1 and W2 (16 months later, N = 1453). We additionally examined whether each effect estimate differed by use of other tobacco products at W1. Results Odds ratios, attributable risk%, and risk differences for product initiation among susceptible vs. non-susceptible youth were consistently higher among never users of any tobacco product than among youth with any tobacco use history. For example, susceptible (vs. non-susceptible) youth with no prior tobacco use had 3.64 times the odds of subsequent initiation of e-cigarettes (95%CI:2.61,5.09), while among users of another product, susceptible (vs. non-susceptible) youth had 1.95 times the odds of e-cigarette initiation (95%CI:0.98,3.89; p-interaction = 0.016). 60.4% of e-cigarette initiation among never users of any product could be attributed to susceptibility, compared to 19.8% among users of another product. The e-cigarette absolute risk difference between susceptible and non-susceptible youth was 21.9%(15.2,28.6) for never users, vs. 15.4%(0.2,30.7) for users of another product. Conclusion Tobacco product-specific susceptibility associations with initiation of use at W2 were markedly attenuated among prior users of other products, demonstrating reduced utility for these measures among subjects using other products.

Purpose Little is known about whether adolescent cigarette and e-cigarette use patterns over time differ by ethnicity. Methods Data were pooled from three prospective cohort studies of adolescents in California and Connecticut (baseline: 2013–2014; 12-month follow-up: 2014–2015; N = 6,258). Adjusted polytomous regression models evaluated the association of baseline exclusive ever e-cigarette use, exclusive ever cigarette use, ever use of both e-cigarettes and cigarettes (dual use) with past 30-day use at follow-up (exclusively e-cigarettes, exclusively cigarettes, dual use; no use at baseline/follow-up were the referent groups). Interaction analyses evaluated differences by race/ethnicity (Hispanic white [HW], non-Hispanic white [NHW], Other). Results A significant global interaction was observed for the association of baseline with follow-up tobacco use by ethnicity (p = .009). Among NHW participants, ever e-cigarette or cigarette users at baseline (vs. never users) had significantly higher odds of every past 30-day use tobacco use pattern at follow-up. Among HW participants, compared with never users, exclusive e-cigarette users at baseline had increased odds of continued e-cigarette use (ORexclusive e-cigarettes = 5.22; 95% confidence interval [CI]: 3.50, 7.79; ORdual use = 3.64; 95% CI: 1.62, 8.18) but not of transition to exclusive cigarette use at follow-up (ORexclusive cigarettes = 1.27; 95% CI: .47, 3.46), and HW exclusive cigarette users at baseline had greater odds of continued cigarette use (ORexclusive e-cigarettes = 12.3; 95% CI: 5.87, 25.8; ORdual use = 3.82; 95% CI: 1.06, 13.7) but not of transition to exclusive e-cigarette use at follow-up (ORexclusive cigarettes = 1.61; 95% CI: .62, 4.18). Conclusions Findings that NHW youth report more transitional use patterns and HW youth report more stable use patterns suggest a potential for differential impacts of e-cigarettes, by ethnicity, in increasing subsequent transition to or cessation from cigarette smoking.

To review the implementation of the WHO Framework Convention onTobacco Control in theAmericas, describe two national case studies and analyze the evidence on electronic cigarettes from a public health perspective.Revision of the tobacco control legislation and the scientific evidence regarding electronic cigarettes.Implementation of tobacco control policies is not homogeneous, with important advances in smoke-free environments, pictorial health warnings, and epidemiological surveillance, but challenges that remain for the implementation of a total ban of tobacco advertising, increases in tobacco taxes, and tobacco cessation programs. Tobacco industry interference is one of the main obstacles for advancing and novel products create uncertainty about their regulation.There is a need for political will for a comprehensive implementation of the Convention, with evidence-based decisions to confront challenges and to defend the achievements from tobacco industry interference.Revisar la aplicación del Convenio Marco de la OMS para el Control del Tabaco en las Américas, describir dos estudios de caso nacionales y analizar la evidencia sobre los cigarrillos electrónicos desde la perspectiva de salud pública.Revisión de la legislación de control de tabaco y la evidencia científica sobre los cigarrillos electrónicos.La aplicación de políticas no es homogénea, con avances importantes en ambientes libres de humo, advertencias sanitarias gráficas y vigilancia epidemiológica, pero desafíos pendientes en la prohibición total de la publicidad, incremento de impuestos y cesación tabáquica.La interferencia de la industria tabacalera es uno de los principales obstáculos para avanzar y los nuevos productos crean incertidumbre sobre su regulación.Se necesita revitalizar la voluntad política para aplicar integralmente el Convenio, tomando decisiones basadas en evidencia ante los nuevos desafíos y defendiendo los logros de la interferencia de la industria.

PURPOSE OF REVIEW: E-cigarettes are available in a variety of flavors not found in traditional tobacco products (i.e., “nontraditional flavors”), which is a commonly-cited reason for e-cigarette use. This review examines the prevalence of nontraditional-flavored e-cigarette use, mechanisms through which flavorings enhance product appeal, use of nontraditional-flavored e-cigarettes for smoking cessation, and differences in these findings between youth and adults. RECENT FINDINGS: Nontraditional-flavored e-cigarettes are used at e-cigarette initiation by the majority of youth. These flavors enhance the appeal of e-cigarettes by creating sensory perceptions of sweetness and coolness and masking the aversive taste of nicotine. Use of nontraditional-flavored e-cigarettes is higher among youth and young adults (vs. older adults) and among nonsmokers (vs. combustible cigarette smokers). SUMMARY: Nontraditional-flavored e-cigarettes are popular among youth, but may be less common among older adults and combustible cigarette smokers. Further research is needed to determine whether use of e-cigarettes in nontraditional flavors affects smoking cessation.

Objectives In this study, we identified groups of adolescents who share similar awareness and perceptions of harm regarding e-cigarettes, cigars, hookah, and smokeless tobacco. Methods We used latent class analyses (LCA) with the data from Wave 1 (2013-14) of the Population Assessment of Tobacco and Health youth and parent survey (PATH; N = 13,650) to address the research goal. Multinomial logistic regression analysis assessed the associations between identified classes with demographic characteristics and tobacco use. Results LCA identified 5 classes: (1) perceived harm across all alternative tobacco products (36.6%); (2) perceived harm for e-cigarettes and smokeless tobacco but never heard of cigars and hookah (48.2%); (3) never heard of alternative tobacco products (8.6%); (4) mix of no harm and harm across alternative tobacco products (5.2%); and (5) "don't know" the harm across alternative tobacco products (1.4%). Relative to the class who perceived harm across all alternative tobacco products, classes of adolescents who were unaware of the products or did not know the harms were more likely to be non-white, younger, have lower parental education, and less likely to have tried an alternative tobacco product. Conclusions Tobacco prevention should target vulnerable youth, such as adolescents who are non-white, young, and have low parental education.

Objective Tobacco control policies have decreased tobacco use among youth and young adults. We aimed to identify whether specific local tobacco retail licensing ordinances were associated with reasons for e-cigarette use, in order to examine whether strong local policies may reduce e-cigarette initiation rates by influencing the appeal of these products. Methods Online questionnaires were completed by Southern California Children's Health Study participants in 2015–2016 (mean age = 18.9 years). Those who had ever used an e-cigarette (N = 614) were asked about reasons for use; additional data were collected on local jurisdiction tobacco sales policy, friends' attitudes toward e-cigarette use, e-cigarette characteristics (level of nicotine, flavorings), and history of tobacco use. Multivariate logistic regression models evaluated associations of each factor with reasons for e-cigarette use, adjusting for gender, ethnicity, highest parental education, tobacco use history and with a random effect of jurisdiction. Results The top reason for e-cigarette use was “They come in flavors I like” (56.6%). Using e-cigarettes to quit smoking was uncommon (12.8%). Participants in jurisdictions with weaker tobacco retail licensing ordinances were more likely to report use of e-cigarettes because they are less harmful than cigarettes (50.1% vs. 36.2%), more acceptable to non-tobacco users (38% vs. 25%), and because they can use e-cigarettes in places where smoking is prohibited (30.7% vs. 18.3%; all p Conclusion Targeted policy to enforce a strong regulatory environment that denormalizes e-cigarette use, conveys the adverse impact of e-cigarettes, and restricts use in public places may reduce e-cigarette use among adolescents and young adults.