E-cigarette Product Characteristics and Subsequent Frequency of Cigarette Smoking

Does the time to nicotine dependence vary by internalizing symptoms for young people who use e-cigarettes? An analysis of the Population Assessment of Tobacco and Health (PATH) study, (Waves 1-5; 2013-2019)

OBJECTIVE

To determine the relationship between past-year internalizing symptoms and the time to first report of signs of nicotine dependence among young people.

METHODS

Secondary analysis using data from the Population Assessment of Tobacco and Health (PATH) (Waves 1-5; 2013-2019). The study included 2,102 (N = 5,031,691) young people (age 12-23 years) who reported past-30-day (P30D) e-cigarette use in one or more waves. Kaplan Meier curves, stratified by past year internalizing symptoms were used to estimate the time to the first report of three nicotine dependence symptoms (i.e., use within 30 min of waking, cravings, and really needing to use) following the first P30D e-cigarette use. Cox proportional hazard models were used to estimate crude and adjusted hazard ratios (AHR), comparing any past year internalizing symptoms to no past year internalizing symptoms.

RESULTS

We found no significant differences between past year internalizing symptoms and the time to the first report of cravings (AHR = 1.30, 95 % CI = 92-1.85), really needing to use (AHR = 1.31; 95 % CI = 0.92-1.89) and use within 30 min of waking for follow-up times 0-156 weeks (AHR = 0.84; 95 % CI = 0.55-1.30) and > 156 weeks (AHR = 0.41; 95 % CI = 0.04-4.67) respectively.

CONCLUSION

Past year internalizing symptoms did not modify the time to the first report of nicotine dependence among youth with P30D e-cigarette use. Further research is needed to understand how changing internalizing symptoms and e-cigarette use frequency influence nicotine dependence over time and, how this relationship impacts cessation behavior.

Psychometric Properties of Instruments That Measure Vaping Outcome Expectancies: A Systematic Review

INTRODUCTION

Vaping is a growing public health concern. Interventions that address vaping must build upon rigorous research that uses psychometrically sound instruments to measure vaping-associated outcome expectancies.

AIMS AND METHODS

The primary aim was to appraise the reporting of psychometric properties of instruments used to measure vaping outcome expectancies. Secondary aims were to distinguish the different types of outcome expectancies assessed across the measures, the conceptual underpinnings, and the evidence explaining e-cigarette use etiology. This systematic review was guided by an adapted version of the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline and Risk of Bias Checklist. Five electronic databases were searched for peer-reviewed studies, dissertations, and theses that psychometrically evaluated instruments that measure vaping outcome expectancies. Studies that met the inclusion criteria were appraised based on their reporting of nine psychometric properties outlined in the COSMIN checklist.

RESULTS

The review included 11 studies that described eight instruments and reported on two to five of nine predetermined psychometric properties. Structural validity, construct validity, and internal consistency were the most commonly reported properties. No studies reported test-retest, intrarater, or interrater reliability, measurement error, or responsiveness. Content validity and measurement invariance were only reported by two and four studies, respectively. The most commonly included subscales in the instruments were affect regulation, positive sensory experience, and negative health consequences. Many of the outcome expectancy subscales were associated with e-cigarette behaviors.

CONCLUSIONS

There is limited reporting of psychometric testing of instruments that measure vaping outcome expectancies; however, utilization of the COSMIN guideline could enhance the quality of such reporting.

IMPLICATIONS

Appraising the reporting of psychometric properties of instruments that measure vaping outcome expectancies is a first step to ensuring valid and reliable instruments are used to support rigorous research and build evidence-based knowledge. Future research should focus on testing for responsiveness, measurement error, and reliability, and on quality appraisal of the instruments. Studying vaping outcome expectancies may improve understanding of factors that influence and deter vaping. This may contribute to the development of effective interventions aimed at vaping cessation and prevention.

Nicotine and fluoxetine alter adolescent dopamine-mediated behaviors via 5-HT1A receptor activation

Introduction

Abuse or misuse of tobacco, e-cigarettes, or antidepressants may have serious clinical consequences during adolescence, a sensitive period during brain development when the distinct neurobiology of adolescent serotonin (5-HT) and dopamine (DA) systems create unique behavioral vulnerabilities to drugs of abuse.

Methods

Using a pharmacological approach, we modeled the behavioral and neurochemical effects of subchronic (4-day) nicotine (60µg/kg, i.v.) or fluoxetine (1mg/kg, i.v.) exposure in adolescent and adult male rats.

Results

Nicotine and fluoxetine significantly enhance quinpirole-induced locomotor activity and initial cocaine self-administration in adolescents, but not adults. These effects were blocked by serotonin 5-HT1A receptor antagonists, WAY-100,635 (100 µg/kg, i.v.) or S-15535 (300 µg/kg, i.v.). Neurochemical and anatomical autoradiographic analysis of 8-OH-DPAT-stimulated [35S]GTPγS reveal that prior exposure to nicotine and fluoxetine results in both overlapping and distinct effects on regional 5-HT1A receptor activity. Both fluoxetine and nicotine enhance adolescent 5-HT1A receptor activity in the primary motor cortex (M1), whereas fluoxetine alone targets prefrontal cortical neurocircuitry and nicotine alone targets the amygdala.

Discussion

Given their different pharmacological profiles, comparison between WAY-100,635 and S-15535 indicates that postsynaptic 5-HT1A receptors mediate the behavioral effects of prior nicotine and fluoxetine exposure. In addition, within the adolescent M1, maladaptive changes in 5-HT signaling and 5-HT1A activity after nicotine or fluoxetine exposure may potentiate hyper-responsiveness to dopaminergic drugs and prime adolescent vulnerability for future substance abuse.

Importance of Various E-Cigarette Device and E-Liquid Characteristics by Smoking Status among Young Adults Who Vape

BACKGROUND

E-cigarette product characteristics are known to influence appeal among young adults. Understanding which characteristics appeal to individuals with (vs. without) a history of combusted tobacco use is essential for developing effective tobacco control policies.

METHODS

Anonymous, self-report data were collected from young adults (18-30 years) who had used e-cigarettes in the past 30 days (n = 295) online via Prolific from September-October 2019. Using a visual analogue scale (range: 0-100), participants rated the importance of ten e-cigarette device and nine e-liquid characteristics. Adjusted linear regression models were used to evaluate the association of combusted tobacco use status (never, former, current) with mean rating scores for each of the nineteen characteristics.

RESULTS

The most important e-cigarette device characteristics were price (Mean = 81.1; [SD = 17.9]), size (Mean = 75.5 [SD = 20.9]), and hit strength (Mean = 73.8 [SD = 20.4]) while the most important e-liquid characteristics were flavor (M = 85.1 [SD = 16.3]), price (M = 80.9 [SD = 18.4]), and nicotine level (M = 77.8 [18.9]). Differences by combusted tobacco use status were observed for device brand, temperature/voltage, customizability, color, and popularity, with the highest ratings generally observed among those concurrently using combustible tobacco products. For e-liquids, differences by use status were observed for flavor, price, and bottle type. Notably, those concurrently using combusted products rated flavor as less important than those with no history of combustible tobacco use (B=-5.01[95%CI=-9.97, -0.05]).

CONCLUSIONS

The self-rated importance of e-cigarette device and e-liquid attributes varies by combustible tobacco use status among young adults which may be used to inform regulatory decisions regarding e-cigarette product characteristics.

Relationship Between Product Features and the Prices of e-Cigarette Devices Sold in Web-Based Vape Shops: Comparison Study Using a Linear Regression Model

BACKGROUND

Open-system electronic cigarette (EC) product features, such as battery capacity, maximum output wattage, and so forth, are major components that drive product costs and may influence use patterns. Moreover, continued innovation and monitoring of product features and prices will provide critical information for designing appropriate taxation policies and product regulations.

OBJECTIVE

This study will examine how product features are associated with the prices of devices sold in web-based vape shops.

METHODS

We draw samples from 5 popular, US-based, web-based vape shops from April to August 2022 to examine starter kits, device-only products, and e-liquid container-only products. We implemented a linear regression model with a store-fixed effect to examine the association between device attributes and prices.

RESULTS

EC starter kits or devices vary significantly by type, with mod prices being much higher than pod and vape pen prices. The prices of mod starter kits were even lower than those of mod devices, suggesting that mod starter kits are discounted in web-based vape shops. The price of mod kits, mod device-only products, and pod kits increased as the battery capacity and output wattage increased. For vape pens, the price was positively associated with the volume size of the e-liquid container. On the other hand, the price of pod kits was positively associated with the number of containers.

CONCLUSIONS

A unit-based specific tax, therefore, will impose a higher tax burden on lower-priced devices such as vape pens or pod systems and a lower tax burden on mod devices. A volume- or capacity-based specific tax on devices will impose a higher tax burden on vape pens with a larger container size. Meanwhile, ad valorem taxes pegged to wholesale or retail prices would apply evenly across device types, meaning those with advanced features such as higher battery capacities and output wattage would face higher rates. Therefore, policy makers could manipulate tax rates by device type to discourage the use of certain device products.

Time to first report of signs of nicotine dependence among youth who use e-cigarettes and cigarettes in the United States: A nationally representative cohort study, findings from the Population Assessment of Tobacco and Health, 2013-2019

OBJECTIVE

To determine the time to first report of signs of nicotine dependence among youth exclusive e-cigarette users and compare this time to that for exclusive cigarette users.

METHODS

Secondary analysis of data (Waves 1-5; 2013-2019) from the Population Assessment of Tobacco and Health was conducted. Youth never tobacco users in the United States who reported exclusive past-30-day (P30D) e-cigarette or cigarette use (n = 2940, N = 5,391,642) in at least one wave were included in the current analysis. Survival analysis was used to estimate the time to the first report of three nicotine dependence indicators (i.e., "use within 30 minutes of waking"; "cravings" and "really needing to use") following the first report of P30D use. Multivariable Cox proportional hazard models were used to estimate adjusted hazard ratios (aHR).

RESULTS

There were no significant differences in the time to first report of "use within 30 minutes of waking" (aHR = 1.1, 95% CI = 0.87-1.40) and "cravings" (aHR = 1.09, 95% CI = 0.81-1.47) between exclusive P30D e-cigarette use and exclusive P30D cigarette use. However, compared to exclusive P30D e-cigarette use, the hazard of first reporting "really needing to use" tobacco was 39% (aHR 1.39; 95% CI: 1.05-1.84) times higher for those who reported exclusive P30D cigarette use after controlling for covariates.

CONCLUSION

Compared to exclusive P30D cigarette use, no differences in the time to first report of signs of nicotine dependence ("use within 30 minutes" and "cravings") were observed among exclusive P30D e-cigarette users. Policymakers and regulatory agencies should consider this evidence when assessing the abuse liability of e-cigarette products.

Symptoms of nicotine dependence by e-cigarette and cigarette use behavior and brand: A population-based, nationally representative cross-sectional study

BACKGROUND

Many modern e-cigarette brands contain equivalent or higher nicotine levels than traditional cigarettes.

OBJECTIVE

To examine differences in four nicotine dependence indicators (i.e., use within 30minutes of waking, cravings, needing to use, and frequent use) among adolescents (aged 12-17 years) with past 30-day (P30D) exclusive use of e-cigarettes, cigarettes, or dual use of both.

METHODS

Data were from Wave 5 (2018-2019) of the Population Assessment of Tobacco and Health (PATH) study (n=1060; N=2053,659). Multivariable logistic regression was performed to determine differences in indicators by P30D e-cigarette and cigarette use behavior (exclusive vs. dual use) and brand (e-cigarette use: JUUL vs. non-JUUL vs. Unknown).

RESULTS

The odds of frequent use among adolescents with JUUL (AOR: 2.11; 95% CI=1.02-4.37) and non-JUUL (AOR: 2.12; 95% CI=0.95-4.77) use were similar and paralleled that for dual use (AOR: 3.50; 95% CI=1.46-8.43) but were stronger (JUUL only) than exclusive cigarette use. The odds of using within 30minutes of waking for adolescents with JUUL (AOR: 2.23; 95% CI=0.80-6.25) and non-JUUL (AOR:1.42; 95% CI=0.47-4.32) use were similar and paralleled that for both dual (AOR=3.00; 95% CI=1.01-8.88) and exclusive cigarette use. For adolescents who used unknown brands, the odds of all indicators paralleled exclusive cigarette use but were lower than JUUL, non-JUUL, and dual use.

CONCLUSION

Compared to exclusive cigarette use, symptoms of nicotine dependence are similar for adolescents with exclusive e-cigarette use, irrespective of brand. Symptoms of nicotine dependence for JUUL and non-JUUL use parallel dual use. Tobacco regulation should consider these findings when assessing the abuse liability of e-cigarettes.

Latin America and the Caribbean Code Against Cancer 1st edition: Tobacco and nicotine-related products, secondhand smoke, and alcohol and cancer

Tobacco, secondhand smoke (SHS), and alcohol, all carcinogens, are leading preventable cancer risk factors in Latin America and the Caribbean (LAC). Since 2000, smoking and SHS exposure have significantly decreased in the region. Yet alcohol consumption remains high. The entry of nicotine-related products such as electronic cigarettes (e-cigs) threatens achievements made in tobacco control and chronic diseases prevention, including cancer. E-cigs use is likely associated with smoking initiation among adolescents who had never smoked and dual use with combustible tobacco products. Therefore, the LAC Code Against Cancer recommends to the public actions they can take to reduce their risk of cancer: 1. Don't smoke or use any type of tobacco. If you do, quitting is possible, with professional help if needed. Don't use e-cigarettes either, as they lead to tobacco use. 2. Make your home a smoke-free place. Respect and promote laws that ensure smoke-free spaces to protect our health. and 3. Avoid drinking alcoholic beverages. This helps prevent several types of cancer. The Code recommends to policymakers a package of cost-effective policies based on the MPOWER and SAFER to prevent cancer at the population level. It also recommends that primary care health professionals: 1. Ask all their patients and their families whether they smoke or vape, inform them about the harms of smoking and vaping, and promote tobacco and nicotine related products cessation strategies among users. 2. Inform about the harms of exposure to SHS, especially among children, and promote smoke-free environments, and 3. Prevent alcohol use by their patients and their families, use tools to assess use, intensity, and frequency, and apply brief counseling intervention to support alcohol abstinence in primary care.

Socio-temporal contextual and community factors associated with daily exclusive ENDS use and dual use with tobacco cigarettes among adolescent vapers: an ecological momentary assessment study

BACKGROUND

Adolescents who dual use ENDS with tobacco cigarettes are more likely to have an increased risk of developing dependence. Yet, little is understood about the factors driving dual use among adolescents. The current study sought to reveal the day-to-day socio-temporal contextual and community factors associated with adolescents' use of electronic nicotine delivery systems (ENDS), and how these factors predict dual use with tobacco cigarettes.

METHODS

We collected ecological momentary assessments (EMA) from a sample of 50 adolescent past two-week vapers (ages 14-17 years old) over 14 days. Daily EMA data were collected on ENDS and tobacco cigarette use, as well as a range of contextual (i.e., motivations to vape, location of vaping, who with when vaping) and community factors (i.e., exposure to peers vaping, to adults vaping, to ENDS advertising, to ENDS warning messages). Our primary analyses were multilevel regressions, accounting for daily observations nested within individuals (N = 700 observations).

RESULTS

Participants used ENDS exclusively on 44% of days and dual used ENDS and tobacco cigarettes on 8% of the days. Dual use days (versus exclusive ENDS use days) were associated with "vaping because tobacco use was prohibited" (OR = 34.65, p < .05). Also, dual use days (versus no use days) were associated with greater exposure to adults vaping (OR = 5.59, p < .05), peers vaping (OR = 7.48, p < .05), and (c) ENDS advertisements or promotions (OR = 2.12, p < .01), whereas exclusive use days (versus no use days) were only associated with greater exposure to peers vaping (OR = 2.58, p < .01).

CONCLUSIONS

Results showed that exposure to peers and adults vaping and exposure to ENDS marketing were associated with same day dual use behaviors. And, that adolescents who dual used were motivated to use ENDS because they were easy to conceal. Findings support stricter regulation of ENDS marketing and for smoke-free air laws that include ENDS. In addition, these findings support prioritizing family- and school-based prevention programming that effectively communicates risk associated with ENDS use, including heightened risk of dual use and dependence. Such efforts can reduce the number of adolescents who use ENDS as well as the number who transition to tobacco cigarette use.

Effect of flavored E-cigarette bans in the United States: What does the evidence show?

The United States federal government, along with many state and local governments, have passed restrictions on electronic cigarette ("e-cigarette") sales with the stated purpose of preventing youth use of these products. The justification for these restrictions includes the argument that youth e-cigarette use will re-normalize youth smoking, leading to increased rates of cigarette smoking by teenagers. However, in this paper, we propose an evidence-based version of this model based on several years' worth of longitudinal and econometric research, which suggests that youth e-cigarette use has instead worked to replace a culture of youth smoking. From this analysis, we propose a re-evaluation of current policies surrounding e-cigarette sales so that declines in e-cigarette use will not come at the cost of increasing cigarette use among youth and adults.

The interaction of nicotine concentration and device power on electronic nicotine delivery system (ENDS) abuse liability among exclusive ENDS users and dual users of ENDS and combustible cigarettes

Open-system electronic nicotine delivery systems (ENDS) permit modifications to device characteristics such as power, potentially increasing nicotine and toxicant delivery. Limiting liquid nicotine concentration may carry unintended consequences by prompting users to increase device power to increase nicotine delivery. This study examined the abuse liability of ENDS across nicotine concentration and power settings. In a clinical laboratory study, n = 19 exclusive ENDS users and n = 13 dual ENDS/cigarette users, aged 21-55 completed four Latin-square ordered conditions that varied by liquid nicotine concentration (10 mg/ml [low], 30 mg/ml [high]) and device power (15 watts [low], 30 watts [high]), that were followed by a fifth own brand (OB) condition. A progressive ratio task (PRT) using bar presses to earn ENDS puffs was used to assess abuse liability and compare between conditions using mixed effects linear regressions. The low nicotine/high watt condition was associated with a significantly higher number of bar presses and puffs earned relative to the OB ENDS, high nicotine/high watt, and high nicotine/low watt conditions (p < .05). Findings appeared to be driven largely by exclusive ENDS users; most comparisons were not significant among dual users. Participants worked significantly harder for puffs of low nicotine/high watt ENDS, highlighting previous findings that suggest limiting liquid nicotine concentration without addressing power settings may be insufficient to reduce the abuse liability of ENDS. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Association of device type, flavours and vaping behaviour with tobacco product transitions among adult electronic cigarette users in the USA

BACKGROUND

Few studies assess whether electronic cigarette (e-cigarette) device characteristics or flavours impact longitudinal patterns of cigarette and e-cigarette use.

DESIGN

We examined data from waves 2-4 of the Population Assessment of Tobacco and Health Study (2014-2018). Among adult (≥18 years) current e-cigarette users at wave 2 who were current smokers (dual users; n=1759) and former smokers (exclusive e-cigarette users; n=470), we classified participants into four use patterns at wave 3 (~12 months later) and wave 4 (~24 months later): (1) dual use of e-cigarettes and cigarettes; (2) exclusive cigarette smoking; (3) exclusive e-cigarette use; (4) non-use of both products. We used multinomial logistic regression to assess correlates of changing use patterns at 24 months, relative to no change, adjusting for sociodemographic factors.

RESULTS

At 24 months, 26.5% of baseline exclusive e-cigarette users, and 9% of baseline dual users, abstained from both vaping and smoking. Participants who vaped non-tobacco flavours (vs tobacco flavours), and used refillable tank or modifiable devices (vs disposable, cartridges and other devices) were less likely to transition to non-use of both products and to exclusive cigarette smoking. Baseline daily vaping (vs non-daily) was positively associated with exclusive e-cigarette use at 24 months for baseline daily cigarette smokers, but negatively associated with exclusive e-cigarette use and non-use of both products at 24 months for baseline non-daily smokers.

CONCLUSIONS

Non-tobacco flavours, daily vaping and modifiable e-cigarette devices may help some smokers abstain from cigarette smoking via transitioning to exclusive e-cigarette use, but are also associated with ongoing exclusive e-cigarette use.

Methods and Statistical Analyses in Studies of Motivation for E-Cigarette Use Among University Students: An Integrative Review

Understanding the motivations for e-cigarette use among college and university students is essential for developing and implementing effective interventions. Evaluating existing literature is necessary to identify methodological gaps and limitations and improve the quality of future research. We aimed to evaluate the quality of the methods and statistical analyses and integrate evidence addressing motivations for e-cigarette use among college and university students. An integrative literature review was conducted by two researchers to identify and evaluate peer-reviewed, quantitative, and mixed methods research exploring motivations for e-cigarette use among college and university students. A systematic analytic method of data reduction was used to identify alignment and divergence of the data, gaps in the literature, and methodological limitations. Fifteen quantitative studies and three mixed methods studies published between 2015-2020 were included. Most studies were cross-sectional, used convenience sampling, and lacked psychometric and assumptions testing. Half performed regression analyses, however, very few adhered to research and statistical reporting standards. Current literature provides a foundation for developing and implementing interventions aimed to prevent e-cigarette use and encourage cessation. Future research should incorporate stronger sampling methods and research designs, as well as the use of rigorous statistical analyses in conjunction with thorough reporting. Supplemental data for this article is available online at https://doi.org/10.1080/10826084.2021.1990332.

Dripping Technology Use Among Young Adult E-Cigarette Users

BACKGROUND

Young adults are increasingly using electronic nicotine delivery systems (ENDS). The standard ENDS device involves an electric coil that heats a wick to vaporize an e-liquid solution. "Dripping" is another method that involves applying e-liquid directly to the coil. Dripping increases risk of harmful toxic compounds in vapor aerosols. Despite evidence of high levels of dripping among adolescents, young adult prevalence is unknown.

METHODS

Young adults aged 18 to 24 completed an online survey assessing vaping and dripping status, type of devices used, tobacco use, and vaping expectancies. Among ever-vapers, univariate and multivariate logistic regression models assessed whether demographics predicted dripping and use of dripping devices. Multivariate Analysis of Variance compared never- and ever-drippers on expectancies for vaping outcomes.

RESULTS

Over 2 in 5 young adult ever-vapers (43.7%) reported dripping. A multivariate regression model found that male gender (AOR = 1.83), identifying as White (AOR = 2.37), and use of other tobacco products (hookah; AOR = 1.91; cigars; AOR = 2.26; cigarettes; AOR = 2.51) were associated with dripping. E-cigarette users who reported lifetime dripping were more likely to consider vaping stimulating, socially facilitating, and flavorful. They ascribed lower health risks to vaping and felt it could reduce negative affect, weight gain, nicotine cravings, and boredom (all P < .05).

CONCLUSION

Dripping was a highly prevalent behavior among this sample of young adults, particularly among White males. These findings point to the importance of gaining a greater understanding of the drivers and consequences of vaping and dripping behavior.

Effects of electronic cigarette aerosol exposure on oral and systemic health

Conventional cigarette smoke harms nearly every organ of the body and is the leading cause of death in the United States and in the world. Decades of research have associated conventional cigarette smoke with several diseases and death. Heavily marketed, electronic nicotine delivery systems such as electronic cigarettes (e-cigarettes) are available in a variety of flavors and high nicotine concentrations. In 2019, a severe lung disease outbreak linked to e-cigarette use led to several deaths, which was called electronic-cigarette or vaping product use-associated lung injury (EVALI). Even though the trend of e-cigarette use among teens continues to increase, information on the effects of e-cigarette smoke on oral and overall health are still scarce. This review discusses the possible health effects due to unregulated e-cigarette use, as well as the health effects of second-hand smoke and third-hand smoke on non-smokers.

Prevalence of Young Adult Vaping, Substance Vaped, and Purchase Location Across Five Categories of Vaping Devices

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.

ENDS Device Type and Initiation of Combustible Tobacco Products Among Adolescents

INTRODUCTION

The aim of this study was to determine whether Electronic Nicotine Delivery Systems (ENDS) device type (disposable devices, replaceable cartridges, and refillables) at initial or first ENDS use predicts subsequent initiation of combustible tobacco products (cigarettes, hookah, cigars) among adolescents and/or differentiates between those who initiate use of both ENDS and combustible tobacco products at the same time.

METHODS

The study examined data from the Texas Adolescent Tobacco and Marketing Surveillance System (TATAMS), a longitudinal population-based cohort of students in major metropolitan areas of Texas (n = 3907; N = 461 069). Data were collected every 6 months, from 2014 to 2018; 33.9% (n = 1324; N = 151 784) of the sample initiated ENDS use across this period. Unadjusted and adjusted logistic regression models were used to assess the odds of initiating combustible tobacco products at a subsequent or similar wave as ENDS initiation, given initial ENDS device type.

RESULTS

After adjusting for sociodemographic factors, the odds of initiating combustible tobacco use subsequent to ENDS initiation were significantly lower among those who reported using Cartridges as their initial device type compared to those who reported Refillables as their initial device type (adjusted odds ratio = 0.42 [0.18-0.98], p = .05). In addition, after controlling for sociodemographic variables, the odds of initiating combustible tobacco use in the same wave as ENDS initiation were significantly higher among those who reported using Cartridges as their initial device type, compared with those who reported Refillables as their initial device type (adjusted odds ratio = 2.31 [1.05-5.10], p = .04). No significant differences were found in adjusted models when Disposables were compared to Refillables and Cartridges to Disposables.

CONCLUSION

ENDS device type differentiates between adolescents who start using combustible tobacco products at the same time as initial ENDS use, or subsequently.

IMPLICATIONS

Previous research has shown ENDS use predicts subsequent combustible use among adolescents, but there is lack of research on the role of specific ENDS device types and the timing of initiation. Findings from this longitudinal study show that initiation of combustible tobacco product use varies by initial ENDS device type among adolescents. These findings can become a focal point for developing interventions for adolescents and could have regulatory implications for ENDS products.

Machine Learning-Based Nicotine Addiction Prediction Models for Youth E-Cigarette and Waterpipe (Hookah) Users

Despite the harmful effect on health, e-cigarette and hookah smoking in youth in the U.S. has increased. Developing tailored e-cigarette and hookah cessation programs for youth is imperative. The aim of this study was to identify predictor variables such as social, mental, and environmental determinants that cause nicotine addiction in youth e-cigarette or hookah users and build nicotine addiction prediction models using machine learning algorithms. A total of 6511 participants were identified as ever having used e-cigarettes or hookah from the National Youth Tobacco Survey (2019) datasets. Prediction models were built by Random Forest with ReliefF and Least Absolute Shrinkage and Selection Operator (LASSO). ReliefF identified important predictor variables, and the Davies–Bouldin clustering evaluation index selected the optimal number of predictors for Random Forest. A total of 193 predictor variables were included in the final analysis. Performance of prediction models was measured by Root Mean Square Error (RMSE) and Confusion Matrix. The results suggested high performance of prediction. Identified predictor variables were aligned with previous research. The noble predictors found, such as ‘witnessed e-cigarette use in their household’ and ‘perception of their tobacco use’, could be used in public awareness or targeted e-cigarette and hookah youth education and for policymakers.

Young adult e-cigarette use: A latent class analysis of device and flavor use, 2018-2019

OBJECTIVE

The myriad of e-cigarette devices and flavors used by young adults (YAs) complicates identification of the particular e-cigarette products that are associated with more frequent tobacco use and merit consideration for regulation. The current study used latent class analysis to identify distinct patterns of e-cigarette device and flavor use and evaluate their association with vaping and smoking frequency.

METHODS

Cross-sectional survey data (2018-2019) from a Southern California cohort were analyzed. YAs reporting past 30-day nicotine vaping (N = 550; M age = 19.2 years) self-reported e-cigarette device type/brand and flavor. Six device (e-cig/vape pen, mech mod, box mod, JUUL, non-JUUL pod, disposable) and three flavor (tobacco, mint/menthol, sweet/fruit) indicators were included in a latent class analysis. Past 30-day nicotine vaping and cigarette smoking frequency were assessed as correlates of device and flavor class membership.

RESULTS

Three classes were identified: Any Pod-Mint/Menthol or Sweet/Fruit Flavor Users (prevalance:47%); Non-JUUL-Sweet/Fruit Flavor Users (28%); and Poly-Device-Poly-Flavor Users (25%). Greater frequency of vaping and smoking were associated with higher odds of belonging to the Poly-Device-Poly-Flavor Users class vs. the Any Pod-Mint/Menthol or Sweet/Fruit Flavor Users (vaping: aOR[95%CI] = 1.36[1.16, 1.59], p < .001; smoking: aOR[95%CI] = 1.25[1.02, 1.54], p = .03) and Non-JUUL-Sweet/Fruit Flavor Users (vaping: aOR[95%CI] = 1.30[1.10, 1.53], p < .01; smoking: aOR[95%CI] = 1.42[1.07, 1.88], p = .02) classes.

CONCLUSIONS

Although YAs that predominately used pod devices alongside non-tobacco flavors were most common, YAs characterized by a proclivity toward using many different devices and flavors were appreciably prevalent and smoked and vaped more frequently. Regulations targeting a wide spectrum of vaping products may be optimal in protecting YA health.

An update on controversies in e-cigarettes

E-cigarettes are electronic nicotine delivery systems (ENDS) which mimic tobacco smoking without the combustion of tobacco. These devices have been misleadingly marketed as "less harmful" alternatives to conventional smoking tobacco products. The e-liquid in e-cigarettes include nicotine, a humectant and other additives including flavourings, colourants, or adulterants such as bacterial and fungal products. In this review, we discuss the contrasting views of the tobacco lobby and most professional societies. We describe the epidemiology of the use of these devices, with a widespread and significant rise in youth e-cigarette use seen in both the USA and Europe. We also describe what is known about the toxicity and mechanisms of EVALI (e-cigarette or vaping associated lung injury). This characterised by respiratory failure with an intense inflammatory response. The presentations are diverse and clinicians should consider vaping as a possible cause of any unusual respiratory illness in patients who have a history of vaping or other use of e-cigarette-related products. Second hand exposure to e-cigarettes is also harmful through respiration and transdermal absorption. E-cigarettes have a worse acute toxicity than tobacco and their long-term toxicity is unknown, and we advocate for the immediate, most vigorous anti-vaping legislation possible.

Potential effects of E-cigarettes and vaping on pediatric asthma

Asthma is the most common chronic disease in childhood and exposure to tobacco smoke has been long recognized as a risk factor for its onset as well as for exacerbations and poor disease control. Since the early 2000s, electronic cigarettes have been marketed worldwide as a non-harmful electronic alternative to combustible cigarettes and as a device likely to help stop smoking, and their use is continuously rising, particularly among adolescents. However, several studies have shown that vape contains many different well-known toxicants, causing significant cytotoxic and pro-inflammatory effects on the airways in-vitro and in animal models. In humans, a variety of harmful lung effects related to vaping, ranging from bronchoconstriction to severe respiratory distress has been already reported. To investigate the potential effects of vaping in pediatric asthma, we searched relevant published studies in the MEDLINE/PubMed database by combining the adequate Medical Subject Headings terms and key words. At the end of our study selection process, five cross-sectional studies focusing on electronic cigarettes use in adolescents and self-reported asthma and/or other respiratory symptoms, one study focusing on the effects of electronic cigarettes second-hand exposure and one case report were retrieved. These preliminary data support a likely detrimental effect of vaping in asthmatic adolescents. Currently available evidence supports that electronic cigarettes are a potential threat to respiratory health, particularly in adolescents with asthma. High-quality studies on larger population assessing the long-term effects of vape exposure, are urgently needed.