Youth use of e-cigarettes: Does dependence vary by device type?

An observational human laboratory assessment of nicotine delivery, vaping topography and subjective effects of usual brand electronic cigarette use among young adults

AIMS

To measure nicotine delivery, vaping topography and subjective effects of current generations of disposable, cartridge-based and other types of electronic cigarettes (e-cigarettes) among young adults.

DESIGN, SETTING, PARTICIPANTS

Observational, human laboratory assessment of e-cigarette use in Columbus, Ohio, USA (July 2020 to June 2021). Participants (n = 96, 60.4% female, age mean = 21.7 [standard deviation = 1.7] years, 82.4% white race) were identified via their participation in a cohort study or other convenience sampling and were 18 to 25 years old, vaped ≥4 days/week for ≥4 weeks and used other tobacco products for ≤5 days of past 30 days. Participants completed a pre-vaping questionnaire, vaped their usual brand of e-cigarette ad libitum for 30 min and completed a post-vaping questionnaire.

MEASUREMENTS

Outcome variables included pre- and post-vaping measures of plasma nicotine (t = 0 and t = 30, respectively) and craving and withdrawal symptoms, as well as vaping topography (e.g. flow rate and inter-puff interval), pre-vaping expectancies and post-vaping product appeal. Variables used to characterize the sample included demographics, e-cigarette and other tobacco use history, e-cigarette dependence and e-cigarette device characteristics (e.g. device type, flavor and nicotine form).

FINDINGS

Participants reported moderate nicotine dependence on average via the E-Cigarette Dependence Scale (mean = 6.9 [standard deviation = 4.0]). Following 30 min of ad libitum vaping, participants achieved substantial plasma nicotine boost (mean = 18.8 [standard deviation = 14.5] ng/mL), corresponding with statistically significant decreases in withdrawal symptoms measured via the Minnesota Nicotine Withdrawal Scale (pre-vaping mean = 9.0 [standard deviation = 5.1], post-vaping mean = 4.3 [standard deviation = 3.9]; P-value <0.0001). Pre-vaping, participants reported moderate vaping expectancies (e.g. mean = 2.5 [standard deviation = 1.0] on a scale from 0 to 4 for smell and taste expectancies); post-vaping, participants reported high satisfaction (mean = 4.6 [standard deviation = 1.2] on a scale from 1 to 7) and moderate reward (mean = 2.9 [standard deviation = 1.2]) and respiratory sensations (mean = 3.7 [standard deviation = 1.6]). Nearly half of participants (47.9%) used disposable e-cigarettes, and most used a mint/menthol or fruit flavored (99.0%) and nicotine salt (98.9%) e-liquid.

CONCLUSIONS

Among young adults in the United States, the latest generations of e-cigarettes appear to deliver large quantities of nicotine (similar to cigarettes) and significantly relieve withdrawal symptoms, and they are appealing.

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.

Nicotine Dependency Levels Among Adult Electronic Cigarette Smokers in Jeddah, Saudi Arabia: An Analytical Cross-Sectional Study

BACKGROUND

Electronic cigarettes (ECs) are a recent method to deliver nicotine with less harmful effects than traditional cigarettes. Studying nicotine dependence in adult EC users is a crucial area, but few measures are available to evaluate nicotine dependence induced by EC. Our study aims to estimate the levels of nicotine dependency among adult EC smokers using a modified Fagerström Test of Nicotine Dependence (e-FTND) in Jeddah, Saudi Arabia, and to identify EC-associated sociodemographic and smoking-related factors affecting nicotine dependency.

METHODS

An analytical cross-sectional study was conducted on adults 18 years of age and older in Jeddah, Saudi Arabia, from December 2023 to March 2024. Data were collected from the participants using a pre-tested structured self-administered questionnaire, and nicotine dependence was assessed using the modified e-FTND. Descriptive statistics such as frequency, mean, and standard deviation were applied. Chi-square was used to assess the association between categorical variables. Ordinal regression was used to predict the nicotine dependency levels with different variables.

RESULTS

A total of 344 participants were included in the study. The mean e-FTND score for EC users was 4.14 ± 2.45. Females had a lower likelihood of experiencing higher dependence compared to males (OR = 0.52, 95% CI: 0.32, 0.85). Using ECs for more than three years was associated with higher odds of increased dependence (OR = 3.18, 95% CI: 1.28, 7.98; p < 0.001). The use of Pod system devices lowered the odds of developing high nicotine dependence (OR = 0.32, 95% CI: 0.13, 0.75; p = 0.01) compared to Iqos device users, while mechanical Mod device users exhibited a trend towards higher dependence, although it was not statistically significant. Nicotine concentration in ECs had a significant impact on the degree of nicotine dependence. Higher concentrations were associated with increased odds of higher dependence (12-18 mg: OR = 3.26, 95% CI: 1.55, 6.91; >18 mg: OR = 4.53, 95% CI: 2.37, 8.75; p < 0.001).

CONCLUSION

Most exclusive EC users in the study developed a moderate nicotine dependence level. The EC device type and nicotine concentration were significant drivers of nicotine dependence. Additionally, the personal characteristics of the users, such as male gender and duration of use, were associated with a higher risk of dependence. An in-depth understanding of the magnitude of nicotine dependence among EC users will enhance the opportunity for tailored health-enhancing interventions and policies.

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.

Disposable E-Cigarette Use and Subsequent Use Patterns in Adolescents and Young Adults

BACKGROUND AND OBJECTIVES

Disposable electronic cigarettes (e-cigarettes) are widely used by adolescents and young adults (AYAs). Whether using disposable devices is associated with future e-cigarette use patterns is unknown but important for informing e-cigarette regulation.

METHODS

Prospective longitudinal study combining data from adolescent (14-17 years) and young adult (21-24 years) cohorts from Southern California surveyed at baseline and approximately 8-month follow-up during 2021 to 2022. The analyses included AYAs who used e-cigarettes in the past 30 days at baseline and had exposure and outcome data (N = 403; adolescent n = 124, young adult n = 279).

RESULTS

In the pooled sample of AYAs who used e-cigarettes at baseline (57.2% cis-gender female, 56.2% Hispanic), 278 (69.0%) reported past 30-day disposable e-cigarette use, and 125 (31.0%) used only nondisposable e-cigarettes. Baseline use of disposable (versus only nondisposable) devices was associated with higher odds of continued e-cigarette use (adjusted odds ratio = 1.92; 95% confidence interval = 1.09-3.42) and a greater number of times used e-cigarettes per day at follow-up (adjusted incidence rate ratio = 1.29; 95% confidence interval = 1.02-1.63). In supplemental analyses, disposable e-cigarette use was associated with greater odds of no changes (versus reductions) in e-cigarette use frequency and puffs per episode from baseline to follow-up but was not associated with increases in use frequency and intensity. No differences in e-cigarette use outcomes were found between those with poly-device (disposable and nondisposable) versus only disposable device use.

CONCLUSIONS

Use of disposable e-cigarette devices among AYAs may be associated with higher risks for persistent e-cigarette use patterns, which should be considered in tobacco product regulation designed to protect AYAs.

The association between excise taxes and smoking and vaping transitions-Findings from the 2016-2020 ITC United States surveys

BACKGROUND

While a growing number of studies examined the effect of e-cigarette (EC) excise taxes on tobacco use behaviors using cross-sectional surveys or sales data, there are currently no studies that evaluate the impact of EC taxes on smoking and vaping transitions.

METHODS

Using data from the US arm of the 2016-2020 International Tobacco Control Four Country Smoking and Vaping Survey (ITC 4CV), we employed a multinomial logit model with two-way fixed effects to simultaneously estimate the impacts of cigarette/EC taxes on the change in smoking and vaping frequencies.

RESULTS

Our benchmark model suggests that a 10 % increase in cigarette taxes led to an 11 % reduction in smoking frequencies (p < 0.01), while EC taxes did not have a significant effect on smoking frequencies.

CONCLUSION

Our findings suggest that increasing cigarette taxes may serve as an effective means of encouraging people who smoke to cut back on smoking or quit smoking. The impact of increasing EC taxes on smoking transitions is less certain at this time.

Factors Associated With Successful E-Cigarette Cessation Among a Convenience Sample of Adult Users

Background: A growing body of literature suggests that many people who use e-cigarettes become dependent and have difficulty quitting. Most people who use e-cigarettes have interest in quitting, yet there is currently a lack of evidence to inform interventions for e-cigarette cessation. Objective: The purpose of this study was to identify factors associated with successful e-cigarette quit attempts among a large sample of people who use e-cigarettes. Methods: Participants (n=586) were people who use e-cigarettes who reported at least one lifetime attempt to quit their e-cigarette use. Adjusted logistic regression models were performed to examine differences in e-cigarette use characteristics and quit methods between people who currently use e-cigarettes and who quit e-cigarettes. Results: Most participants were people who currently use e-cigarettes and only 27.5% reported successfully quitting. Most participants (90.6%) used e-cigarettes that contained nicotine, and over half (54.0%) used closed-system e-cigarette devices with replaceable pre-filled pods or cartridges. The quit method most commonly used overall (63.1%) and for people who quit e-cigarettes (70.8%) was cold turkey. Past 30-day cigarette use and past 30-day other tobacco use was significantly associated with reduced odds of quitting, and there were no e-cigarette characteristics significantly associated with successful cessation. Nicotine replacement therapy was the only e-cigarette cessation method that was significantly associated with increased odds of quitting after adjusting for past 30-day cigarette and other tobacco use. Conclusions: These results suggests that cigarette use, other tobacco use, and quit method used may significantly influence the likelihood of e-cigarette cessation. Future research is needed to determine the effectiveness of interventions for e-cigarette cessation using nicotine replacement therapy.

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.

Prevalence of use, perceptions of harm and addictiveness, and dependence of electronic cigarettes among adults in Kuwait: A cross-sectional study

INTRODUCTION

Electronic cigarettes (e-cigarettes) have become one of the most common forms of nicotine delivery used by youth and young adults worldwide. Given the lack of epidemiologic data in Kuwait, this study sought to estimate the prevalence of e-cigarette use, assess perceptions of harm and addictiveness of e-cigarettes, measure the level of dependence on e-cigarettes and assess factors associated with dependence level among adults.

METHODS

A cross-sectional study enrolled adults (n=3032, aged ≥18 years) living in Kuwait using a web-based questionnaire. Participants self-reported ever and current (past 30-day) e-cigarette use and self-completed the 10-item Penn State E-cigarette Dependence Index. Associations were evaluated using multinomial logistic regression.

RESULTS

The prevalence of ever and current e-cigarette use was estimated to be 40.2% (1220/3032) and 29.4% (892/3032), respectively. The prevalence of current e-cigarette use was higher in males compared to females (47.6% vs 14.4%, p<0.001). Relative to cigarette smoking, 40.6% of participants reported that e-cigarettes are less harmful, and 41.8% indicated that e-cigarettes are equally addictive. Among current e-cigarette users (n=892), 84.8% were ascertained to have developed either low, medium, or high dependence. The use of pod-based devices compared to disposable devices was associated with a high dependence level (adjusted odds ratio, AOR=8.56; 95% CI: 4.52-16.22).

CONCLUSIONS

These findings suggest that a large proportion of adults in Kuwait use e-cigarettes, and a considerable proportion of current users have developed dependence. Therefore, such results should alert public health authorities and warrant the development of evidence-based awareness campaigns, policies, and prevention measures to protect and improve the health of people.

Effects of dual use of e-cigarette and cannabis during adolescence on cigarette use in young adulthood

INTRODUCTION

E-cigarette and cannabis use by adolescents are risk factors for smoking initiation. We hypothesised that increasingly common dual use of e-cigarette and cannabis in adolescence leads to more frequent cigarette smoking in young adulthood.

METHODS

Data are from a prospective cohort study in Southern California, where 1164 participants who ever used nicotine products in their lifetime completed surveys in 12th grade (T1:2016), and at 24-month (T2) and 42-month (T3) follow-ups. Past 30-day use (number of days: range=0-30) of cigarettes, e-cigarettes and cannabis, and nicotine dependence, were assessed in each survey. Nicotine dependence for cigarettes and e-cigarettes was assessed using original and modified (for e-cigarette) Hooked on Nicotine Checklists (number of dependent products: range=0-2). Path analysis examined the mediation process via nicotine dependence linking baseline e-cigarette and cannabis use to subsequent increased cigarette use.

RESULTS

Baseline exclusive use of e-cigarettes (baseline prevalence, 2.5%) was associated with 2.61-fold increase in frequency of smoking days at T3 (95% CI 1.04 to 13.1), exclusive cannabis use (26.0%) with 2.58-fold increase (95% CI 1.43 to 4.98), and dual use (7.4%) with 5.84-fold increase (95% CI 3.16 to 12.81), compared with baseline non-users. Nicotine dependence at T2 mediated 10.5% (95% CI 6.3 to 14.7) and 23.2% (95% CI 9.6 to 36.3) of the association of cannabis and dual use, respectively, with increased smoking at T3.

DISCUSSION

Adolescent e-cigarette and cannabis use was associated with more frequent smoking during young adulthood, with larger effects of dual use. Associations were partially mediated through nicotine dependence. Dual use of cannabis and e-cigarettes may contribute to the development of nicotine dependence and increased use of combustible cigarettes.

Exclusive and dual use of electronic cigarettes among European youth in 32 countries with different regulatory landscapes

BACKGROUND

The Tobacco Products Directive (2014/40/EU) partially harmonised the regulation of electronic cigarettes (e-cigarettes) in Europe, but individual countries maintain jurisdiction over bans on use in public places, domestic advertising, taxation and flavour regulations. Their association with youth e-cigarette use has not been examined.

METHODS

We used the cross-sectional 2019 European School Survey Project on Alcohol and Other Drugs data from 32 countries with 98 758 students aged 15-16 years and the 2020 WHO's assessment of the e-cigarette regulations. Multilevel logistic regression models on ever (vs never) and current (vs non-current) exclusive e-cigarette use, exclusive cigarette use and dual use by e-cigarette regulations' composite score were adjusted for age, gender, parental education, perceived family's financial well-being, perceived difficulty of obtaining cigarettes, country income level and general progress in tobacco control.

RESULTS

Of the respondents, 13.3% had ever used cigarettes, 10.6% e-cigarettes and 27.3% both; 13.0% currently used cigarettes, 6.0% e-cigarettes and 6.4% both. Higher composite country score in the e-cigarette regulations was associated with lower current exclusive e-cigarette use (OR=0.78; 95% CI 0.65 to 0.94) and current dual use (OR=0.80; 95% CI 0.67 to 0.95). Youth perceiving more difficulties in obtaining cigarettes were less likely to use cigarettes, e-cigarettes and both ever and currently (OR from 0.80 (95% CI 0.76 to 0.85) to 0.94 (95% CI 0.92 to 0.96)).

CONCLUSIONS

More comprehensive e-cigarette regulations and enforcement of age-of-sale laws may be protective of e-cigarette and dual use among adolescents.

Use of electronic nicotine delivery system (ENDS) devices among U.S. Youth and adults: Findings from the Population Assessment of Tobacco and Health Study Waves 1-5

INTRODUCTION

Electronic nicotine delivery system (ENDS) devices evolve rapidly and impact nicotine dependence. This study described the type of ENDS devices used most frequently by U.S. youth and adults from 2013/14 to 2018/19.

METHODS

We analyzed Waves 1-5 data of the Population Assessment of Tobacco and Health Study. Among current ENDS users, descriptive statistics summarized the most frequently used ENDS devices (i.e., disposable cigalike, refillable cartridge, nonrefillable cartridge, tank, mod, prefilled pod, disposable pod) among youth (12-17 years), young adults (18-34 years), and older adults (≥35 years) for each wave.

RESULTS

The proportion of current ENDS users who reported they most frequently used disposable cigalikes and cartridge-based devices declined over time across all age groups. At Waves 1-4, tank was generally the most popular type for all ages and an increasing proportion of ENDS users reported they most frequently used tanks. The primary use of mods decreased among youth, and fluctuated among young and older adults. At Wave 5, prefilled pods became the dominant type (youth: 55.0%; young adults: 44.7%; older adults: 42.7%), and 4.2-10.0% of ENDS users reported using disposable pods most often. The popularity of tanks, mods, and prefilled pods was more evident in youth and young adults, and primary use of disposable pods was more common in older adults.

CONCLUSIONS

The primary use of ENDS devices changed over the years and varied by age. More research is warranted to continuously monitor the characteristics of ENDS devices in youth and adults to inform product regulations and intervention efforts.

E-cigarette Device Type, Source, and Use Behaviors of Youth and Young Adults: Findings from the Truth Longitudinal Cohort (2020-2021)

Background: E-cigarette device types vary in the amount of nicotine delivered to users. Given that youth and young adults are using pod-based and disposable e-cigarettes with high nicotine concentrations, it is important to determine how e-cigarette use behaviors associated with nicotine dependence may differ across e-cigarette device type. Methods: Baseline information was collected from September 2020 to March 2021 and follow-up information was collected from July to October 2021 from the Truth Longitudinal Cohort. The final analytic sample included respondents (aged 15-24) who reported current use of e-cigarettes at either baseline or follow-up and provided information on the 4-item E-cigarette Dependence Scale (EDS). Differences in endorsement of items from the EDS by e-cigarette device type (pod-based, disposable, or tank) were assessed using chi-square tests. Results: Participants (N = 308) were evenly split on age (15-20, 21+) and gender. Most 15-20-year-olds used disposable e-cigarettes, while those 21+ years primarily used tank devices. Although EDS score did not differ by e-cigarette device type, positive endorsement of two items from the EDS significantly differed by e-cigarette device type. More tank users endorsed reaching for a device without thinking about it (tank: 92.6%; pod-based: 79.0%; disposables: 79.9%, p = 0.04) and vaping more before going into a situation where vaping is not allowed (tank: 92.9%; pod-based: 71.0%; disposables: 73.0%, p < 0.01). Conclusions: Findings have the potential to inform policy implementation by providing evidence for specific targets for regulatory action that can help to reduce the burdens of e-cigarette use among youth and young adults, as results suggest that tank device users are more likely to endorse use behaviors associated with nicotine dependence.

Evaluation of the Psychometric Properties of Dependence Measures for Exclusive Electronic Cigarette Users

INTRODUCTION

Extant electronic cigarette (ECIG) dependence measures are largely adapted from those designed for cigarette smoking, though few have been evaluated for their psychometric properties.

AIMS AND METHODS

Never-smoking ECIG users (N = 134) participating in an online survey completed four dependence measures: Penn state electronic cigarette dependence index (PSECDI), e-cigarette dependence scale (EDS-4), diagnostic and statistical manual for tobacco use disorder (DSM-5), and Glover Nilsson behavioral questionnaire (GNBQ). They also reported on their ECIG use characteristics (eg, behaviors and reasons).

RESULTS

Internal consistency was highest for the EDS-4 (Cronbach's α = 0.88) followed by the GNBQ (α = 0.75), PSECDI (α = 0.72), and DSM (α = 0.71). Confirmatory factor analyses revealed a single-factor structure for the PSECDI, EDS-4, and GNBQ. For the DSM-5, however, two items did not load significantly (ECIG use interferes with responsibilities; reduce/give up activities because of ECIG use). Significant correlations were observed between all measures and the number of ECIG use days/week and/or years using ECIGs, as well as between DSM-5 scores and the number of ECIG quit attempts and initiation age. Endorsement of using ECIGs because "I like flavors" was correlated positively with DSM-5 and GNBQ scores.

CONCLUSIONS

All dependence measures evaluated herein demonstrated adequate reliability and construct validity. Future work should focus on determining which aspects of dependence are those that are unique to ECIG use, and subsequently developing a more comprehensive measure of ECIG dependence.

IMPLICATIONS

The measures assessed herein-PSECDI, EDS-4, DSM-5, and GNBQ-demonstrated adequate to good reliability and construct validity among a sample of never-smoking ECIG users. The dependence domains covered across measures were related yet distinct. Findings demonstrate the need for future evaluation of these different domains to determine which are the most salient characteristics of ECIG dependence.

Predictors of electronic cigarette dependence among non-smoking electronic cigarette users: User behavior and device characteristics

INTRODUCTION

ECIGs differ in their ability to deliver nicotine to the user and, consequently, they may differ in their ability to produce dependence. This study examined individual device characteristics, device type, and user behaviors as predictors of ECIG dependence in a sample of never-smoking ECIG users.

METHODS

Participants (N = 134) completed an online survey that assessed demographics, ECIG use behavior, and ECIG dependence as measured via the Penn State Electronic Nicotine Dependence Index (PSECDI) and E-cigarette Dependence Scale (EDS-4). Participants uploaded a picture of their personal ECIG device/liquid, which was coded by raters to identify product features. Multivariable linear regressions examined device characteristics (e.g., adjustable power, nicotine concentration) and device type (e.g., vape pen, mod, pod, modern disposable) as predictors of dependence controlling for demographics and user behaviors (e.g., ECIG use duration and frequency, other tobacco use).

RESULTS

Longer durations of ECIG use and more use days/week were associated significantly with higher PSECDI (β's = 0.91 and 1.90, respectively; p's < 0.01) and EDS-4 scores (β's = 0.16 and 0.28, respectively; p's < 0.01). Higher nicotine concentrations were associated with higher PSECDI scores only (β = 0.07, p =.011). Dependence scores did not differ as a function of ECIG device types after controlling for covariates.

CONCLUSIONS

ECIG dependence was observed among the never-smoking ECIG users in this sample, regardless of their ECIG device/liquid features. Findings suggest that regulatory efforts aimed at reducing the dependence potential of ECIGs in never smokers should focus on overall nicotine emissions rather than product features.

Electronic nicotine delivery systems (ENDS) dependence among Texas Young Adults, 2014-2019: Increasing trajectory after the 2017 surge in vape pod popularity

INTRODUCTION

Use of electronic nicotine delivery systems (ENDS) increased significantly after 2017. The increase is attributed to a surge in popularity of vape pods containing nicotine salts, which are high nicotine concentration ENDS that may heighten risk for dependence. However, little is known about changes in ENDS dependence before and after the 2017 surge. We examined the trajectory of ENDS dependence among young adults from 2014 to 2019.

METHODS

Participants were 1700 18-25-year-olds (57.6 % female) from 24 Texas colleges who reported past 30-day ENDS use in at least one of eight study waves. ENDS dependence was assessed at all waves with one item, use of ENDS within 30 min of waking. A discontinuous growth curve model was fit to test the hypothesis that the ENDS dependence trajectory would increase only after 2017, from 2018 to 2019. The model included socio-demographic and cigarette dependence covariates RESULTS: The proportion of young adults reporting ENDS dependence ranged from 2.3 % in 2014 to 8.2 % in 2019. Results from the discontinuous growth curve model indicated that the ENDS dependence trajectory was flat from fall 2014 to spring 2017. However, the post-2017 trajectory, from spring 2018 to spring 2019, was positive and significant indicating that the proportion of young adults reporting ENDS dependence increased after 2017.

CONCLUSIONS

The increase in ENDS dependence after 2017 likely resulted from the surge in popularity of vape pods containing nicotine salts. These vape pods are a disruptive technology that may result in more young adults developing nicotine dependence symptoms than do earlier generation devices.

Associations between living in localities with e-cigarette sales restrictions and e-cigarette use change among young adults in Los Angeles County

INTRODUCTION

Local e-cigarette sales restrictions (ESRs) may impact e-cigarette use. This study examined the associations between living in localities with various ESR policies and changes in e-cigarette use among young adults in Los Angeles (LA) County, California, USA.

METHODS

Data were from a cohort of LA County young adults (18-21 years; n=2100) who completed two waves of surveys (Fall 2018-Summer 2019 and Summer-Fall 2020). Local flavoured (n=9) and comprehensive (n=2) ESRs in LA County implemented between June 2019 and May 2020 were identified, coded and merged with the baseline data. Multivariable logistic regressions were used to examine the associations between living in ESR localities and e-cigarette use at follow-up, controlling for covariates and stratified by cigarette smoking at baseline.

RESULTS

Overall, 20.9% and 14.3% of participants lived in localities with flavoured and comprehensive ESRs, respectively. Participants who were non-Hispanic, had higher socioeconomic statuses and were currently using e-cigarettes were generally more likely to live in ESR localities than their counterparts. The associations between living in ESR localities and e-cigarette use at follow-up were not found among baseline non-e-cigarette users regardless of their cigarette smoking status; a positive relationship was found among baseline e-cigarette users who also smoked cigarettes but not among non-smokers.

DISCUSSION

Participants who lived in localities with various ESR policies were different in their baseline e-cigarette use and socioeconomic backgrounds. Future research examining the potential impact of ESRs on e-cigarette use change should consider the localities' overall sociodemographic and tobacco-using characteristics and individuals' cigarette smoking histories.

Nicotine Addiction and Intensity of e-Cigarette Use by Adolescents in the US, 2014 to 2021

IMPORTANCE

As e-cigarettes have become more effective at delivering the addictive drug nicotine, they have become the dominant form of tobacco use by US adolescents.

OBJECTIVE

To measure intensity of use of e-cigarettes, cigarettes, and other tobacco products among US adolescents and their dependence level over time.

DESIGN, SETTING, AND PARTICIPANTS

This survey study analyzed the cross-sectional National Youth Tobacco Surveys from 2014 to 2021. Confirmatory analysis was conducted using Youth Behavioral Risk Factor Surveillance System from 2015 to 2019. The surveys were administered to national probability samples of US students in grades 6 to 12.

EXPOSURES

Use of e-cigarettes and other tobacco products before and after the introduction of e-cigarettes delivering high levels of nicotine.

MAIN OUTCOMES AND MEASURES

First tobacco product used, age at initiation of use, intensity of use (days per month), and nicotine addiction (measured as time after waking to first use of any tobacco product).

RESULTS

A total of 151 573 respondents were included in the analysis (51.1% male and 48.9% female; mean [SEM] age, 14.57 [0.03] years). Prevalence of e-cigarette use peaked in 2019 and then declined. Between 2014 and 2021, the age at initiation of e-cigarette use decreased, and intensity of use and addiction increased. By 2017, e-cigarettes became the most common first product used (77.0%). Age at initiation of use did not change for cigarettes or other tobacco products, and changes in intensity of use were minimal. By 2019, more e-cigarette users were using their first tobacco product within 5 minutes of waking than for cigarettes and all other products combined. Median e-cigarette use also increased from 3 to 5 d/mo in 2014 to 2018 to 6 to 9 d/mo in 2019 to 2020 and 10 to 19 d/mo in 2021.

CONCLUSIONS AND RELEVANCE

The changes detected in this survey study may reflect the higher levels of nicotine delivery and addiction liability of modern e-cigarettes that use protonated nicotine to make nicotine easier to inhale. The increasing intensity of use of modern e-cigarettes highlights the clinical need to address youth addiction to these new high-nicotine products over the course of many clinical encounters. In addition, stronger regulation, including comprehensive bans on the sale of flavored tobacco products, should be implemented.

Association between Harmful and Addictive Perceptions of E-Cigarettes and E-Cigarette Use among Adolescents and Youth-A Systematic Review and Meta-Analysis

BACKGROUND

Recognising the association between the perceived risks of e-cigarettes and e-cigarette usage among youth is critical for planning effective prevention and intervention initiatives; thus, a systematic review and meta-analysis were performed.

METHODS

Fourteen databases were searched for eligible studies from the Inception of database until March 2022 to examine the effect estimates of the association between perceptions of harmfulness and addictiveness and overall e-cigarette usage among adolescents and youth.

RESULTS

The meta-analysis showed that in comparison to non-users, young people who were ever e-cigarette users were two times more likely to disagree that e-cigarettes are harmful (OR: 2.20, 95% CI: 1.41-3.43) and perceived e-cigarettes as less harmful than tobacco cigarettes (OR: 2.01, 95% CI 1.47-2.75). Youths who were ever e-cigarette users were also 2.3 and 1.8 times more likely to perceive e-cigarettes as less addictive (OR: 2.28, 95% CI: 1.81-2.88) or perceive e-cigarettes as more addictive (OR: 1.82, 95% CI: 1.22-2.73) than tobacco cigarettes, as compared with non-users. The subgroup analysis reported that adolescents were more likely to believe that e-cigarettes are less harmful than tobacco cigarettes, while youth users perceived otherwise.

CONCLUSION

the risk perceptions of e-cigarettes are associated with e-cigarette use among adolescents and youth and could be the focus of health promotion to prevent and curb the uptake of e-cigarettes among young people.

Consumption of JUUL vs. Other E-Cigarette Brands among U.S. E-Cigarette Users: Evidence from Wave 5 of the PATH Study

This study examines the use of JUUL vs. other e-cigarette brands among U.S. youth (12-17 years), young adult (18-24 years), and adult (25 years and above) e-cigarette users. Data were from the Population Assessment of Tobacco and Health (PATH) study Wave 5 survey (2019). The study population was past 30-day e-cigarette users who knew the brand of e-cigarettes they usually/last used (N = 2569). JUUL use was reported by 65.2% of youth, 60.7% of young adult, and 25.6% of adult e-cigarette users in our study sample. The share of JUUL consumed in the past 30 days, measured by the total number of puffs, was 15.4% by youth, 55.5% by young adults, and 29.1% by adults. By contrast, the share of other e-cigarettes consumed was 4.2% by youth, 28.9% by young adults, and 66.9% by adults. Youth JUUL users were more likely to use e-cigarettes within 30 min after waking (aOR = 2.30, 95% CI: 1.12-4.75) than youth users of other brands of e-cigarettes. Additionally, youth e-cigarette users who currently smoked cigarettes were less likely to use JUUL (aOR = 0.55, 95% CI: 0.30-0.99). This study concludes that JUUL consumption was disproportionally higher among youth and young adults in the U.S. in 2019.

Correlates of youth Poly-E-Cigarette device use

PURPOSE

The objective of this study was to examine poly-e-cigarette (poly-EC) device use among youth EC users and identify factors associated with poly- versus single-EC device use status.

METHODS

861 EC users aged 14-21 responded to an online survey about EC use and sociodemographic factors in August 2020. Respondents were included if they were current EC users (i.e., at least one day in the past 30 days) and excluded if they were currently using other tobacco products (OTPs).

RESULTS

Data analysis indicated poly-EC device use was associated with higher self-reported nicotine dependence, younger age of onset, having close friends who use ECs and higher or lower self-perceived socioeconomic status compared to others.

CONCLUSIONS

Young poly-EC device users were more likely to begin using at a younger age, live with and have close friends who were EC users, and report greater nicotine dependence. Identifying temporality in these associations can identify youth at greater risk of poly-EC use. Future research should examine poly-EC device use in prospective surveillance monitoring to further evaluate the longitudinal implications on use and dependence.

Daily E-cigarette Use and the Surge in JUUL Sales: 2017-2019

OBJECTIVES

To identify how the 2017 rapid surge in sales of JUUL e-cigarettes affected usage among US youth and young adults.

METHODS

Annual surveys in the Population Assessment of Tobacco and Health Study assess tobacco use by product and brand among the US population. We identified 2 cohorts aged 14 to 34 years, 1 with baseline survey in 2014 before the rapid surge of JUUL and the other in 2017 as the surge in JUUL sales was occurring. For 5 age groups, we compared 2-year incidence of first tobacco use and of new-onset daily tobacco use by product, and report levels of dependence.

RESULTS

Sociodemographic variables and rates of experimentation with any tobacco product were similar between cohorts. Among baseline nondaily tobacco users, only those aged 14 to 17 years had an increase in the 2-year incidence of new daily tobacco use (2014 cohort = 4.8%, 95% confidence interval 4.3, 5.5 vs 2017 cohort = 6.3%, 95% confidence interval 5.8-7.0) to rates approaching those in the 1990s. In 2019, three-quarters of new daily tobacco users aged 14 to 17 vaped daily and had e-cigarette dependence scores similar to daily cigarette smokers and older adult e-cigarette vapers. We estimate that about 600 000 Americans aged <21 years used JUUL products daily in 2019, a rate 2.5 times those aged 25 to 34 years.

CONCLUSIONS

The surge in US JUUL sales was associated with a sharp rise in daily e-cigarette vaping and daily tobacco use among US youth, not young adults.

Nicotine Dependence from Different E-Cigarette Devices and Combustible Cigarettes among US Adolescent and Young Adult Users

E-cigarettes, the most popular tobacco product among adolescents, vary widely in design and nicotine composition; thus, different devices may have different addictive potential. However, few studies examine levels of nicotine dependence across devices among adolescent and young adult (AYA) e-cigarette users. To assess the extent of nicotine dependence among US AYA (ages 13-24) by e-cigarette device type, we conducted a large, national, cross-sectional survey (n = 4351) and used the Hooked on Nicotine Checklist (HONC) to assess levels of nicotine dependence among those who had used disposable, pod-based, and/or mods/other e-cigarette devices in the past 30 days. We also examined HONC scores among those who had used combustible cigarettes in the past 30 days, whether with or without using e-cigarettes. Patterns of nicotine dependence were comparable across those who had used a combustible cigarette and/or e-cigarette in the past 30 days, with 91.4% of combustible cigarette users, 80.7% of disposable e-cigarette users, 83.1% of pod-based e-cigarette users, and 82.5% of mods/other e-cigarette users showing signs of nicotine dependence, as measured by endorsing at least one HONC symptom. This pattern persisted when analyses were restricted to e-cigarette only users, with more than 70% of all e-cigarette only past-30-day users endorsing at least one HONC symptom, across all types of devices. A thorough understanding of the extent and presentation of nicotine dependence among AYA will help researchers, public health officials, and clinicians recognize and manage AYA nicotine dependence.

Biomarkers of nicotine exposure correlate with the Hooked on Nicotine Checklist among adolescents in California, United States

BACKGROUND

The Hooked on Nicotine Checklist (HONC) has been used to assess nicotine dependence (loss of autonomy over tobacco) among adolescents. Existing HONC validation studies for non-cigarette products, such as electronic cigarettes (e-cigarettes), have generally not considered biomarkers of nicotine exposure.

METHODS

Within a cross-sectional sample of California (USA) high school students (total N = 1396; mean age 15.2 years; 56% female; 54% Hispanic/Latinx), self-reported past 30-day users of any tobacco (including e-cigarettes) completed a modified 10-item HONC questionnaire and provided saliva samples (N = 318 samples, including N = 234 exclusive past 30-day e-cigarette users). Samples were analyzed for cotinine using liquid chromatography-tandem mass spectrometry (lower limit of quantification: 1.0 ng/mL).

RESULTS

Across four categories of HONC score corresponding to an increasing number of reported dependence symptoms (scores: 0, 1, 2-4, 5-10), the prevalence of quantifiable salivary cotinine increased among past 30-day tobacco users (20%, 21%, 38%, 55%, respectively, P-for-trend < 0.001) and among past 30-day exclusive e-cigarette users (15%, 22%, 31%, 42%, respectively, P-for-trend = 0.001). Among participants with quantifiable cotinine levels, HONC total score and cotinine were positively correlated among past 30-day tobacco users (n = 89; Spearman rho = 0.449; P < 0.001) and past 30-day exclusive e-cigarette users (n = 49; Spearman rho = 0.520; P < 0.001). HONC score was also associated with past 30-day frequency of tobacco product use and reported use of tobacco within 30 min of waking.

CONCLUSIONS

These results support the validity of HONC to assess nicotine dependence among adolescents. Dependence symptoms may be experienced at low levels of nicotine exposure.

Electronic Nicotine Delivery System (ENDS) Device Types and Flavors Used by Youth in the PATH Study, 2016-2019

The evolving electronic nicotine delivery system (ENDS) marketplace and recent regulatory actions may influence youth ENDS device preferences. Using data from Waves (W) 4, 4.5, and 5 (2016–2019) of the nationally representative Population Assessment of Tobacco and Health (PATH) Study, this study estimated the prevalence of open and closed system primary ENDS use by youth (12–17 years) current (past 30-day) ENDS users, and compared demographics, tobacco use characteristics, and patterns of ENDS use, including flavors, by device type. Among current ENDS users, closed system use was significantly higher than open system use in W4.5 (68.3% vs. 31.7%) and W5 (60.5% vs. 39.5%). In W5, closed system users were more likely to have a regular ENDS brand, believe their ENDS had nicotine, and use tobacco and mint or menthol flavors in the past 30 days compared to open system users. In W5, users of closed systems were less likely to use fruit, non-alcoholic drink, and candy, desserts, or other sweets flavors in the past 30 days than users of open systems. Youth were more likely to use closed over open system ENDS in 2017–2019. Differences were observed between device types, particularly with flavor use, reflecting recent changes in flavored product availability.

Device features and user behaviors as predictors of dependence among never-smoking electronic cigarette users: PATH Wave 4

INTRODUCTION

Electronic cigarettes (ECIGs) vary greatly in their ability to deliver nicotine, which suggests they may also vary in their ability to produce dependence. This study examined individual and combined ECIG device features, and also user behaviors, as predictors of dependence in never-smoking ECIG users. Methods Data were collected from 711 current ECIG users who had smoked <100 cigarettes in their lifetime at Wave 4 of the Population Assessment of Tobacco and Health (PATH) Study. Multivariable linear regressions examined individual (e.g., contains nicotine, uses a tank, flavor preference) and combined (e.g., refillable tanks, refillable mods) device features, and user behaviors (e.g., uses/day) as predictors of dependence, withdrawal, and craving after accounting for demographic variables. Results Results for ECIG dependence and craving showed a similar pattern; higher levels were observed for older age, more frequent past 30-day use, using an ECIG containing nicotine (vs no nicotine), and using a non-refillable cartridge or refillable tank style (vs disposables). Higher withdrawal levels were observed for higher education levels and individual device features of tank (vs no tank), cartridge (vs no cartridge), refillable (vs non-refillable), and "other" flavor preference (vs tobacco flavor). Lower withdrawal levels were associated with a preference for sweet/fruit flavor(s) (vs tobacco flavor). Conclusions Few use behaviors and device features, whether examined alone or in combination, predicted dependence-related outcomes. Findings underscore the challenge with regulating ECIG products in the current marketplace, which is inundated with a myriad of device types.

E-cigarette device and liquid characteristics and E-cigarette dependence: A pilot study of pod-based and disposable E-cigarette users

BACKGROUND

E-cigarette device and liquid characteristics, such as electrical power output and liquid nicotine concentration, determine the rate at which nicotine is emitted from the e-cigarette (i.e., nicotine flux), and thus are likely to influence user nicotine dependence. We hypothesize that nicotine flux would be associated with the E-cigarette Dependence Scale (EDS) among pod-based and disposable e-cigarette products.

METHODS

Data were obtained from online panel participants between 18 and 65 years of age, who had indicated that they were either former or current e-cigarette users and resided within the United States (N = 1036). To be included in these analyses, participants had to provide information regarding device type (pod-based or disposable), power (watts), and nicotine concentration (mg/mL), from which we could determine nicotine flux (µg/s) (N = 666). To assess the relationship between nicotine flux and EDS, a series of multivariable linear regressions were conducted. Each model was separated by device type and adjusted for by age and past 30-day e-cigarette use.

RESULTS

Greater nicotine flux was associated with higher EDS scores among pod-based e-cigarette users (beta = 0.19, SE = 0.09, p-value = 0.043), but not users of disposable e-cigarettes. Neither power nor nicotine concentration were associated with EDS scores among users of either e-cigarette device type.

CONCLUSION

Results support the hypothesis that nicotine flux is positively associated with nicotine dependence in a sample of current users of pod-based and disposable e-cigarettes.

Use frequency and symptoms of nicotine dependence among adolescent E-cigarette users: Comparison of JUUL and Non-JUUL users

OBJECTIVE

Nicotine exposure among adolescent e-cigarette users remains a public health concern. JUUL, a popular e-cigarette brand among youth, is particularly alarming given the high nicotine delivery (59 mg/mL). This study compares e-cigarette use frequency and symptoms of nicotine dependence among adolescent JUUL and non-JUUL users.

METHODS

We analyzed data from the 2020 National Youth Tobacco Survey. Participants were n = 1713 U.S. middle and high school students who reported past 30-day e-cigarette use. We compared adolescent e-cigarette users who reported JUUL use to those who did not. Outcomes were: (1) symptoms of nicotine dependence (i.e. nicotine cravings; use within 30 min of waking); (2) past 30-day e-cigarette use frequency, categorized as 1-5 days, 6-19 days, and 20-30 days. Covariates were sex, race/ethnicity, other tobacco product use, primary e-cigarette device type (i.e., disposable; pod; mod/tank).

RESULTS

Overall, 49.5% of adolescent e-cigarette users reported using JUUL in the past 30 days, 40.1% reported symptoms of nicotine dependence, and 36.2% reported using an e-cigarette on 20-30 days. JUUL users were 1.77 (95% CI: 1.36-2.31) times as likely to report symptoms of nicotine dependence and 1.43 (95% CI: 1.02-2.01) time as likely to report using e-cigarettes on 20-30 days, compared to 1-5 days, relative to non-JUUL users, controlling for covariates.

CONCLUSION

JUUL use was associated with greater odds of nicotine dependence and more frequent e-cigarette use among adolescents. Greater prevention and regulatory efforts should be made to prevent adolescent use of high dose nicotine devices such as JUUL.