Dependence on e-cigarettes and cigarettes in a cross-sectional study of US adults

Comparison of Indicators of Dependence for Vaping and Smoking: Trends Between 2017 and 2022 Among Youth in Canada, England, and the United States

INTRODUCTION

The current study sought to examine trends in indicators of dependence for youth vaping and smoking during a period of rapid evolution in the e-cigarette market.

AIMS AND METHODS

Data are from repeat cross-sectional online surveys conducted between 2017 and 2022 among youth aged 16-19 in Canada, England, and the United States (US). Participants were 23 145 respondents who vaped and/or smoked in the past 30 days. Four dependence indicators were assessed for smoking and vaping (perceived addiction, frequent strong urges, time to first use after waking, days used in past month) and two for vaping only (use events per day, e-cigarette dependence scale). Regression models examined differences by survey wave and country, adjusting for sex, age, race, and exclusive/dual use.

RESULTS

All six indicators of dependence increased between 2017 and 2022 among youth who vaped in the past 30 days (p < .001 for all). For example, more youth reported strong urges to vape at least most days in 2022 than in 2017 (Canada: 26.5% to 53.4%; England: 25.5% to 45.4%; US: 31.6% to 50.3%). In 2017, indicators of vaping dependence were substantially lower than for smoking; however, by 2022, youth vaping was associated with a greater number of days used in the past month (Canada, US), shorter time to first use (all countries), and a higher likelihood of frequent strong urges (Canada, US) compared to youth smoking.

CONCLUSIONS

From 2017 to 2022, indicators of vaping dependence increased substantially. By 2022, vaping dependence indices were comparable to those of smoking.

IMPLICATIONS

Indicators of vaping dependence among youth have increased substantially since 2017 to levels that are comparable to cigarette dependence among youth who smoke. Future research should examine factors underlying the increase in dependence among youth who vape, including changes to the nicotine profile and design of e-cigarette products.

Smoking reduction using an electronic nicotine delivery system (ENDS) with nicotine delivery similar to combustible cigarettes

BACKGROUND

Electronic nicotine delivery systems (ENDS) offer a promising approach to tobacco harm reduction, but many people use both ENDS and combustible cigarettes ("dual use"), which undermines potential risk reduction. To explore the role of ENDS nicotine delivery in promoting switching to ENDS, we conducted a study in which people who smoked cigarettes were offered an ENDS that had previously been shown to replicate the rapid nicotine pharmacokinetics of combustible cigarettes (BIDI® Stick).

METHODS

Twenty-five cigarette smoking adults, not seeking smoking cessation treatment, but open to using ENDS as a cigarette substitute, were provided with a 12-week supply of BIDI® Stick in tobacco or menthol flavors, during a study that included seven biweekly sessions and a 6-month follow-up. Daily diaries assessed ENDS and cigarette use, and exhaled carbon monoxide (eCO) served as an objective marker of smoke intake. Subjective ratings were collected to assess the rewarding properties of ENDS and combustible cigarettes, and indices of nicotine dependence.

RESULTS

Over 12 weeks, ENDS use increased to an average of 15.8 occasions per day (SD = 20.2) and self-reported cigarette consumption decreased by 82% from 16.7 cigarettes/day (SD = 6.0) at baseline to 3.0 cigarettes/day (SD = 4.1) at week 12. The eCO level decreased by 27% from an average of 20.0 ppm (SD = 9.8) at baseline to 14.5 ppm (SD = 9.9) at week 12. Four of 25 participants completely switched to ENDS and were smoking abstinent during weeks 9-12. At 6 months one participant was confirmed to be abstinent. Ratings of subjective reward for the ENDS were very similar to those of participants' usual brands of cigarettes. Dependence level was lower for the ENDS than for combustible cigarettes.

CONCLUSIONS

In this study, the ENDS effectively replicated the subjective rewarding effects of participants' usual brands of cigarettes and led to a substantial reduction in reported cigarettes/day. Exhaled CO showed less of a decrease, possibly due to compensatory smoking behavior and/or the timing of eCO measurements that might not have reflected smoke intake throughout the day. The relatively low rate of sustained smoking abstinence at 6 months suggests that additional approaches continue to be needed for achieving higher rates of complete switching.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT05855343.

Measures of youth e-cigarette use: strengths, weaknesses and recommendations

This perspective discusses how to best define "e-cigarette use" among youth in a way that is relevant to individual and human health. Commonly-used definitions of youth e-cigarette use have been adapted from measures validated for tobacco cigarette smoking among adults, but may not carry the same meaning for a different product (with a much lower risk profile and very different patterns of use) and a different population (whose use is more often transient and experimental, rather than frequent and persistent). We discuss strengths and weaknesses of different definitions, and recommend improvements in defining youth e-cigarette use. We find that current literature employs a range of definitions of e-cigarette use, from lifetime use ("even a puff") to daily use. More lenient measures capture more potentially at-risk youth, but much of this is transient experimentation that has negligible risks in and itself, if not persistent. More stringent measures such as daily use are more relevant to individual and public health. Future research should examine possible improvements to definitions which include intensity of use (e.g., number of puffs per day) and persistence/duration of use, either via self-report or technology-assisted data capture.

Longitudinal Assessment of Association Between Tobacco Use and Tobacco Dependence Among Adults: Latent Class Analysis of the Population Assessment of Tobacco and Health Study Waves 1-4

INTRODUCTION

With increasing tobacco product varieties, understanding tobacco use (TU) profiles and their associations with tobacco dependence (TD) has also become increasingly challenging.

AIMS AND METHODS

We aimed to identify TU profiles and their associations with TD over time, and to identify subgroups with high risk of TD. We included 3463 adult recent tobacco users who had complete TU and TD data across waves 1-4 of the Population Assessment of Tobacco and Health (PATH) study. We used a composite index of TD and a summed TD score from an established 16-item TD measure. We applied a latent class analysis to identify TU profiles based on participants' usage of eight common tobacco product groups at each survey wave and to check the stability of the TU profiles over time. We then used generalized estimating equations regressions to evaluate the longitudinal TU-TD association, adjusting for potential confounders.

RESULTS

We identified three distinct TU profiles that remained consistent across four survey waves: Dominant cigarette users (62%-68%), poly users with high propensity of using traditional cigarettes, e-cigarettes, and cigars (24%-31%), and dominant smokeless product users (7%-9%). Covariate-adjusted models showed that TD was significantly lower among the poly users and the dominant smokeless users, compared to that among the dominant cigarette users.

CONCLUSIONS

Both TU profiles and their associations with TD were stable over time at the population level. Poly users and smokeless product users were consistently associated with lower TD than cigarette-dominant users, suggesting the need for tailored tobacco cessation interventions for users with different TU profiles.

IMPLICATIONS

The finding of consistent TU profiles across four survey waves extends the current literature in capturing TU patterns in an evolving tobacco product landscape. The finding of the overall higher level of TD among the cigarette-dominant users compared to the other TU latent profiles (the Cig+eCig+Cigar dominant poly users and the dominant smokeless product users) can help identify high-risk groups for potential interventions. Our application of innovative statistical methods to high-quality longitudinal data from the PATH study helps improve the understanding of the dynamic TU-TD relationship over time.

Psychometric properties of measures for electronic cigarette dependence among former-smoking electronic cigarette users

BACKGROUND

Measures designed to assess electronic cigarette (ECIG) dependence are largely adapted from those developed for cigarette smoking, and have been evaluated mainly among dual ECIG-cigarette users. The present study evaluated the psychometric properties of four dependence measures among former-smoking ECIG users.

METHODS

Respondents (N = 187) were daily ECIG users who had formerly smoked cigarettes regularly. As part of an online survey, they completed four dependence measures: Penn State Electronic Cigarette Dependence Index (PSECDI); E-Cigarette Dependence Scale (EDS-4); Glover Nilsson Behavioral Questionnaire (GNBQ); and Diagnostic and Statistical Manual 5th Edition (DSM-5).

RESULTS

Confirmatory factor analysis revealed a single factor structure for all four measures, and fit indices were adequate for all models. Most inter-item correlations (mean r's = 0.21 to 0.45) and all item-total correlations (mean r's = 0.53 to 0.80) were significant for all four measures. Internal consistency was highest for the GNBQ (α = 0.86) followed by the EDS-4 (α = 0.81), PSECDI (α = 0.76), and DSM-5 (α = 0.75). Age of ECIG initiation was correlated negatively with scores on the EDS-4 and DSM-5, while number of ECIG quit attempts was correlated positively with scores on all measures except the GNBQ. Convergent validity was highest for comparisons between the EDS-4 and PSECDI (r = 0.75) though all comparisons were significant (p's < 0.001).

CONCLUSIONS

All four measures demonstrated acceptable reliability and validity in this sample of former-smoking ECIG users.

Assessment of abuse liability and switching potential of menthol-flavored pod-based electronic nicotine delivery systems among US adults who smoke cigarettes

BACKGROUND

Menthol-flavored electronic nicotine delivery systems (ENDS) are a focus of public health and regulatory policy considerations. The abuse liability of five menthol-flavored pod-based ENDS was compared to combustible cigarettes, and switching potential of ENDS was also evaluated.

METHODS

215 US adults who smoke cigarettes (34.4% female; mean age[SD]=29.60[8.75]; 40.9% non-Hispanic White; mean cigarettes/day[SD]=12.04[8.52]) completed a randomized 6-arm within-person cross-over product-use study. Participants used five pod-based menthol-flavored ENDS (JUUL2 Polar Menthol 1.5%, JUUL2 Prototype Fresh Menthol 3.0%, JUUL Menthol 5.0%, Vuse Alto Menthol 5.0%, NJOY Ace Menthol 5.0%) and their usual brand (UB) cigarette for 20minutes ad libitum. After each product use, subjective reinforcing effects relevant to abuse liability and associated with switching away from cigarettes (e.g., satisfaction, product liking) were assessed.

RESULTS

All ENDS products were rated substantially and statistically significantly lower than UB cigarette on measures of subjective reinforcing effects (ps<0.001). Satisfying effects of JUUL2 1.5% were rated significantly higher than other ENDS products. JUUL2 Prototype 3.0% and Vuse Alto 5.0% did not significantly differ (ps>0.05), and both were rated significantly higher than JUUL 5.0% and NJOY Ace 5.0% (ps<0.05). Differences in subjective responses to study products did not significantly differ by preference for menthol cigarettes or by current ENDS use.

CONCLUSIONS

Abuse liability of all menthol-flavored ENDS in this study was substantially lower than combustible cigarettes. Abuse liability of JUUL2 1.5% was within the range of currently marketed pod-based menthol-flavored ENDS products. JUUL2 1.5% likely has high potential for facilitating switching among US adults who smoke.

Comparing Adult Smokers Who Switched to JUUL versus Continuing Smokers: Biomarkers of Exposure and of Potential Harm and Respiratory Symptoms

OBJECTIVES

Real-world evidence on exposure to harmful and potentially harmful constituents (HPHCs) and on biological effects in cigarette smokers who switch to electronic nicotine delivery systems (ENDS) can inform the health effects of switching.

AIMS AND METHODS

This cross-sectional, observational study assessed adults who had smoked ≥10 cigarettes/day for ≥10 years, comparing 124 continuing cigarette smokers (Smokers) to 140 former smokers who switched to JUUL-brand ENDS exclusively for ≥6 months (Switchers). Assessments included biomarkers of exposure (BOEs) to select HPHCs, biomarkers of potential harm (BOPHs) related to smoking-related diseases, psychometric assessments of dependence on cigarettes and ENDS, respectively, and respiratory symptoms. Planned analyses compared geometric means, adjusted for demographic covariates; further analyses adjusted for additional lifestyle and smoking history covariates.

RESULTS

Nicotine levels were significantly higher in Switchers (median time switched = 3 years), who were unusually heavy users of JUUL. All other BOEs, including NNAL and HPMA3 (primary endpoints), were significantly lower in Switchers than Smokers. Most BOPHs (sICAM-1 [primary], and eg, white blood cell count, MCP1, HbA1c) were significantly lower in Switchers than Smokers; HDL was significantly higher. Switchers reported significantly lower dependence on JUUL than Smokers did on cigarettes, and respiratory symptom scores were significantly lower among Switchers than Smokers.

CONCLUSIONS

Compared to continuing smokers, smokers who switched to JUUL had substantially lower exposures to multiple HPHCs, favorable differences in markers of inflammation, endothelial function, oxidative stress, and cardiovascular risk, and fewer respiratory symptoms. These findings suggest that switching from cigarettes to JUUL likely reduces smokers' health risks.

IMPLICATIONS

Short-term confinement studies and randomized clinical trials demonstrate that adult smokers who switch completely to ENDS experience substantial reductions in exposure to many smoking-related toxicants. This study extends those findings to longer periods of switching to JUUL-brand ENDS (almost 3 years on average) under naturalistic use conditions in real-world settings and also found that switching to JUUL resulted in favorable differences in BOPHs more proximally related to smoking-induced disease, as well as in respiratory symptoms. Smokers who switch to ENDS reduce their exposure to toxicants, likely reducing their disease risk.

Co-occurrence of habit-forming risk behaviors and their socio-demographic, health status and lifestyle determinants: a population-based cross-sectional study

BACKGROUND

Although habit-forming risk behaviors frequently co-occur, determinants of concurrent risk behaviors have rarely been investigated. The aim of the present study was to investigate socio-demographic, health status, and lifestyle determinants of single versus concurrent risk behaviors in general-population adults.

METHODS

We analyzed data from 32,622 participants (74.5% female; mean age = 57.9 ± 14.2 years) of the NutriNet-Santé cohort who completed the Alcohol Use Disorders Identification Test, the 12-item Cigarette Dependence Scale, the modified Yale Food Addiction Scale 2.0, and the Internet Addiction Test in 2021-2022. Using established cutoffs, participants were first split into 2 groups (presence versus absence) for each risk variable (alcohol use disorders, nicotine dependence, food addiction, Internet addiction) and were then divided into 3 groups (no risk behavior, 1 risk behavior (reference), and ≥ 2 risk behaviors). The association between socio-demographic, health status, and lifestyle exposures and individual/concurrent risk behaviors were investigated with polytomous logistic regression.

RESULTS

Younger age (Odds Ratio (OR) = 2.04; 95% Confidence Interval (CI: 1.62-2.56), current financial difficulties (OR = 1.29; CI: 1.08-1.54), self-perceived poor health (OR = 1.70; CI: 1.32-2.20), overall poor dietary quality (OR = 2.88; CI: 2.06-4.02), being underweight (OR = 1.46; CI: 1.05-2.04), having obesity (OR = 1.62; CI: 1.31-1.99), lack of affection during childhood (OR = 1.41; CI: 1.18-1.69), and a lifetime prevalence or medication use for a mental disorder (OR = 1.46; CI: 1.24-1.73) were positively associated with having ≥ 2 versus 1 risk behavior (all p < 0.05). The comparison of none versus 1 risk behavior revealed the same determinants in addition to having a higher education, being physically active at work, and being overweight.

CONCLUSIONS

We investigated determinants of concurrent habit-forming risk behaviors among adults in a large, population-based study. The findings could serve as impetus for future research in this domain and ultimately help guide addiction prevention efforts.

Predictors of Quitting Dual Use of Electronic Cigarettes and Cigarettes During Pregnancy

Background and Aims: There is limited research surrounding dual maternal use of cigarettes and electronic cigarettes (e-cigarettes). We aimed to assess predictors of maternal quitting of cigarettes, e-cigarettes, and both during late pregnancy. Materials and Methods: We analyzed dual use (n = 4,006) and exclusive e-cigarette use (n = 1,685) among mothers using data from the 2016 to 2019 phase of the Pregnancy Risk Assessment Monitoring Systems (PRAMS), a nationally representative sample of the United States. Dual use and exclusive e-cigarette use were defined based on use reported during the 3 months before pregnancy and quitting was assessed during the last 3 months of pregnancy. Multinomial and binomial logistic regression models estimated the odds ratios and 95% confidence intervals for predictors of quitting status among mothers who reported dual use and exclusive e-cigarette use, respectively. Separate predictor analyses were conducted in the dual and exclusive e-cigarette use groups to see predictors of quitting e-cigarettes, cigarettes, or both. Results: The highest proportion of mothers who used cigarettes and e-cigarettes before pregnancy quit both during late pregnancy (46.2%), followed by those who quit e-cigarette use only (26.5%) and those who quit cigarette use only (6.6%). Among mothers who reported dual use, those who were African American or Asian, of Hispanic ethnicity, consumed alcohol before pregnancy, had higher education, were married, had diabetes, had higher annual household income, had nongovernmental health insurance, had more prenatal care visits, had a higher frequency of e-cigarette use before pregnancy, had a lower frequency of cigarette use before pregnancy, and smoked hookah around pregnancy had a higher likelihood of quitting both cigarette and e-cigarette use during late pregnancy. Conclusions: Quitting use of cigarettes and/or e-cigarettes was fairly common among mothers who reported dual use or e-cigarette use only. Sociodemographics, pregnancy characteristics, and use of other tobacco products predicted quitting use of both cigarettes and e-cigarettes during late pregnancy.

Comparative risk perceptions of switching to JUUL vs. continued smoking and subsequent switching away from cigarettes: a longitudinal observational study

BACKGROUND

Evidence indicates that electronic nicotine delivery systems (ENDS) pose lower risk than cigarettes; however, many smokers harbor misperceptions that ENDS are equally or more harmful, possibly deterring them from switching. This study examines whether comparative risk perceptions of JUUL vs. smoking are associated with subsequent switching, among smokers who recently purchased JUUL.

METHODS

N = 16,996 current established smokers who recently purchased a JUUL Starter Kit were followed 6 times over 12 months. Comparative risk perceptions were assessed using both direct and indirect measures (i.e., contrasting JUUL and smoking directly in questions, and deriving from separate absolute scales). Repeated-measures logistic regression examined switching across follow-up (no smoking in past 30 days) as a function of baseline risk perceptions, adjusting for demographics and baseline smoking behavior.

RESULTS

Perceiving JUUL as less harmful than smoking was associated with higher switching rates, using both direct (e.g., adjusted odds ratio [AOR] = 1.48 for "JUUL much less" vs. "more/much more harmful") and indirect (AOR = 1.07, for each 10-unit increase in fraction; AOR = 1.51 for highest (6-100) vs. lowest (0 to < 1) fraction categories) comparative risk measures (all p < 0.0001). Among the subset smoking 10 + cigarettes per day, associations between risk perceptions and switching were more pronounced (AOR = 2.51 for "JUUL much less" vs. "more/much more harmful"; AOR = 1.81 for 6-100 vs. 0 to < 1 fraction, both p < 0.0001).

CONCLUSIONS

Smokers who perceive JUUL as less harmful than cigarettes have higher odds of switching. Future research should examine whether messaging which aligns comparative risk perceptions with current evidence can facilitate switching, especially among heavier smokers.

Switching away from smoking at 12 months among adult JUUL users varying in recent history of quit attempts made with and without smoking cessation medication

Some smokers switch away from smoking using e-cigarettes, but guidelines recommend trying approved medications first. We analyzed switching in adult smokers using JUUL by their recent history of quit attempts and use of smoking cessation medications. Participants were 8511 adult (21+) established smokers (at baseline), in which 50.3% are daily smokers, in a longitudinal observational study who completed a survey 12 months after first purchasing a JUUL Starter Kit. At baseline, participants reported attempts to quit smoking in the prior year and use of pharmacotherapy (nicotine replacement therapy [NRT] or prescription medication) in their most recent attempt. The outcomes were switching (self-reported no past-30-day smoking) and 50%+ reductions in cigarette consumption. Multivariable analyses were adjusted for baseline covariates. Two thirds of the participants had made a quit attempt in the year before purchasing JUUL. Overall, 59% [58%, 60%] had switched at 12 months. Switching was more likely in those who had used NRT and who attempted quitting without medication versus those who used prescription medications or made no quit attempt. In adjusted multivariable analyses, only making a past-year quit attempt (vs. not) was associated with higher odds of switching (OR = 1.15 [1.04, 1.28]). Over 60% of dual users reduced cigarette consumption by ≥50%. These associations were largely similar in daily smokers. Twelve months after purchasing JUUL, almost all smokers reported either switching or reducing their smoking by 50%+, including those who had recently failed to quit smoking with approved pharmacotherapies. E-cigarettes provide an alternative route to abstinence from smoking for smokers with a history of cessation and cessation treatment failure.

Electronic cigarette use and cigarette smoking associated with inadequate sleep duration among U.S. young adults

OBJECTIVE

Nicotine use can influence inadequate sleep, but less is known about the associations of exclusive and dual use of electronic cigarettes (e-cigarettes) with combustible cigarettes in U.S. young adults. This study assessed the associations between current exclusive e-cigarette use, exclusive cigarette smoking, and dual e-cigarette and combustible cigarette use and inadequate sleep duration among U.S. young adults.

METHODS

We performed a secondary analysis of 2020 Behavioral Risk Factor Surveillance System (BRFSS) data including 13,978 U.S. young adults ages 18-24 years. Inadequate sleep duration was assessed categorically using the National Sleep Foundation's age-specific recommendations that define <7 h as inadequate sleep. Weighted logistic regression models were performed while adjusting for participants' sex, race/ethnicity, education level, annual household income level, body mass index, current physical activity, mental health status, disability status, current alcohol use, and current smokeless tobacco use.

RESULTS

Concerning use patterns, 11.8% of young adults were exclusive e-cigarette users, 4.7% were exclusive cigarette smokers, and 3.8% were dual e-cigarette and combustible cigarette users. Exclusive e-cigarette users (adjusted odds ratio [AOR] = 1.41, 95% confidence interval [CI] = 1.16-1.72), exclusive cigarette smokers (AOR = 1.63, 95%CI = 1.22-2.18), and dual product users (AOR = 2.03, 95%CI = 1.44-2.86) were at increased odds of having inadequate sleep duration compared to non-users, while adjusting for the covariates. Additionally, dual product users were at increased odds (AOR = 1.52, 95%CI = 1.06-2.19) of reporting inadequate sleep duration compared to exclusive e-cigarette users, while adjusting for the covariates.

CONCLUSIONS

Current e-cigarette and cigarette use may influence inadequate sleep among U.S. young adults. Tobacco cessation efforts may encourage increased sleep health.

Nicotine dependence and associated factors among persons who use electronic e-cigarettes in Malaysia - an online survey

BACKGROUND

Nicotine dependence, factors associated with dependence, and self-reported side effects among people who use e-cigarettes are scarce in developing countries.

METHODS

A sample of 302 persons who currently use e-cigarettes was recruited from discussion forums on Reddit, Facebook, and the forum 'lowyat'. The online Google form survey collected data on demographics, e-cigarette use, and the reasons, for cigarette smoking, Fagerstorm Test for Nicotine Dependence adapted for e-cigarettes (eFTND), and side effects experienced.

RESULTS

The mean age was 25.5 years (6.5), 60.6% were males and 86% had higher education. About 47% were using e-cigarettes only, 27.8% were currently using dual products (both electronic and conventional cigarettes), and 25.2% had also smoked cigarettes in the past. 'Less harmful than cigarettes' (56.3%), 'because I enjoy it' (46.7%), and 'it has a variety of flavors (40.4%) were the common reasons for e-cigarette use. The mean eFTND score was 3.9 (SD = 2.2), with a median of four side effects (IQR 3-6), sore or dry mouth/throat (41.4%), cough 33.4%, headache (20.5%), dizziness (16.2%) were commonly reported side effects. eFTND score and side effects were higher among persons using dual products. By multiple linear regression analysis, males (β = 0.56 95% CI 0.45, 1.05, p = 0.033), dual-use (β = 0.95 95% CI 0.34, 1.56, p < 0.003), and use of nicotine-containing e-cigarettes (β = 0.66 95% CI 0.07, 1.25 p = 0.024) had higher eFTND score.

CONCLUSION

Our findings of the study call for the placement of disclaimers about possible nicotine addiction and side effects of e-cigarette products.

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.

Longitudinal transitions in e-cigarette and cigarette use among US adults: prospective cohort study

Background

To support tobacco control efforts, this study sought to characterize longitudinal transitions in use of electronic nicotine delivery systems (ENDS) and cigarettes.

Methods

Participants were nationally representative samples of 53,729 US adults from Waves 3-5 (2015-2019) of the Population Assessment of Tobacco and Health Study. We examined behavioral transitions (initiation, relapse, progression, and cessation) in ENDS and cigarette use across waves. Weighted generalized estimating equation models adjusted for sociodemographic variables.

Findings

Of never ENDS users at baseline, an estimated 1.7% reported initiating ENDS use by follow-up. Of former ENDS users, an estimated 12.1% relapsed into ENDS use. Of periodic ENDS users at baseline, 13% progressed to established ENDS use. Of baseline current ENDS users, 46.3% discontinued ENDS use. The corresponding transitions for cigarette smoking were 1.6% (initiation), 4.8% (relapse), 21.1% (progression), and 14% (discontinuation). Adults aged 18-24 (vs. older age), Hispanics (vs. non-Hispanic white), and past 12-month cannabis users were more likely to initiate ENDS or cigarettes (all p < 0.05). Having any internalizing mental health symptoms increased the odds of ENDS initiation, while externalizing symptoms increased the odds of cigarette initiation. Those who perceived nicotine as very harmful (vs. none/low harm) were more likely to discontinue ENDS. Current cigarette users (vs. non-users) at baseline were more likely to initiate, relapse, or discontinue ENDS (all p < 0.05) and vice versa.

Interpretation

We observed high changeability in ENDS and cigarette use among US adults over time. In absolute terms, ENDS use grew, while smoking fell. Tobacco control programs should focus on priority populations, including young adults and people with internalizing and externalizing mental health symptoms.

Funding

National Institutes of Health, R01-CA246606-01A1, R01-DA048390.

The Roswell eND scale: Brief, valid assessment of nicotine dependence adults seeking to discontinue e-cigarette use

BACKGROUND

Most adults who regularly use e-cigarettes or Electronic Nicotine Delivery Systems (ENDS) desire to discontinue use. ENDS use can result symptoms of nicotine withdrawal and dependence which can make it more difficult to discontinue use. Brief, valid assessment of nicotine dependence among adults who use ENDS is needed to guide treatment for nicotine dependence in this group. We sought to develop a brief, valid instrument to measure nicotine dependence among adults seeking to discontinue ENDS in a busy Quitline.

METHODS

In this cross-sectional design, we examined content, construct, and concurrent validity of the Roswell ENDS Nicotine Dependence Scale (Roswell eND Scale) and the Penn State E-Cigarette Dependence Index (Penn State eCDI). Participants who called the New York Quitline from November 2019 to June 2020 seeking to discontinue ENDS use were invited to participate. Construct validity was examined with exploratory and confirmatory factor analyses. Instrument and factor scores were then correlated with cotinine, a biomarker of nicotine exposure.

RESULTS

All participants (n = 209) were highly dependent and co-used combustible cigarettes to varying degrees. Both instruments demonstrated content validity and construct validity, however only the 5-item Roswell eND Scale demonstrated criterion-related validity by showing a significant positive correlation with salivary cotinine levels.

CONCLUSIONS

The 5-item Roswell eND Scale can briefly and effectively assess nicotine dependence among treatment-seeking adults who co-use ENDS and cigarettes. These preliminary psychometric findings have the potential to be generalizable to other adults seeking to discontinue ENDS use, many of whom currently or formerly smoked cigarettes.

Investigating predictors of problematic alcohol, cannabis, and nicotine use among legal users of all three substances

BACKGROUND

The three most used substances-alcohol, cannabis, and nicotine-are frequently concurrently. Use of each substance has been connected to an increased probability of use of the other substances, and the problematic use of each substance has been linked to demographic factors, substance use factors, and personality. However, little is known about which risk factors are most important for consumers of all three substances. This study examined the extent to which various factors are associated with dependence on alcohol, cannabis, and/or nicotine in users of all three substances.

METHODS

516 Canadian adults with past month use of alcohol, cannabis, and nicotine completed online surveys querying their demographics, personality, substance use history, and levels substance dependence. Hierarchical linear regressions were used to determine which factors best predicted levels of dependence on each substance.

RESULTS

Alcohol dependence was associated with levels of cannabis and nicotine dependence, and impulsivity, with 44.9% of variance explained. Cannabis dependence was predicted by alcohol and nicotine dependence levels, impulsivity, and the age of onset of cannabis use, with 47.6% of variance explained. Nicotine dependence was best predicted by alcohol and cannabis dependence levels, impulsivity, and dual use of cigarettes and e-cigarettes, with 19.9% of variance explained.

CONCLUSIONS

Alcohol dependence, cannabis dependence, and impulsivity were the strongest predictors for dependence on each of the substances. A strong relationship between alcohol and cannabis dependence was evident, warranting further research.

Changes in Dependence Over One Year among US Adults Who Smoke Cigarettes and Switched Completely or Partially to Use of the JUUL-Brand Electronic Nicotine Delivery System

Background

Electronic nicotine delivery systems (ENDS) are substitute sources of nicotine for adults who smoke cigarettes. Understanding changes in dependence as people switch from cigarettes to ENDS is relevant to public health. This study assessed changes in dependence among adults who switched completely or partially (dual users) from cigarettes to JUUL-brand ENDS over 12 months.

Methods

US adults who smoke and purchased a JUUL Starter Kit (n = 17,619) completed a baseline assessment and were invited to 1-, 2-, 3-, 6-, 9- and 12-month follow-ups. Dependence on cigarettes at baseline and on JUUL at follow-ups was assessed with the Tobacco Dependence Index (TDI; Range 1-5). Analyses estimated the minimal important difference (MID) for the scale, compared JUUL dependence to baseline cigarette dependence and assessed changes in JUUL dependence over 1-year, including among those using JUUL at all follow-ups.

Results

Participants who switched at month 2 had month 1 JUUL TDI scores 0.24 points greater than those who continued smoking (p<0.001); thus MID=0.24. Among both switchers and dual users overall, dependence on JUUL 1 and 12 months later was lower than baseline dependence on cigarettes (ps<0.001); participants who smoked every day showed more consistent and larger reductions. Among participants who persistently used JUUL without smoking, dependence increased 0.01 points per month (p<0.001), but was leveling off over time.

Conclusions

Dependence on JUUL was lower than baseline cigarette dependence. Increases in JUUL dependence were small over 12 months of continual JUUL use. These data indicate that ENDS, including JUUL, have lower dependence potential than cigarettes.

Part one: abuse liability of Vuse Solo (G2) electronic nicotine delivery system relative to combustible cigarettes and nicotine gum

Abuse liability (AL) of electronic nicotine delivery systems (ENDS) is relevant as the category increases in popularity as a potentially less-harmful alternative to cigarette smoking. AL assessments are important to the FDA in determining if a new product is appropriate for the protection of public health. This paper reports the results for Vuse Solo (G2 cartridge design) compared to high and low AL-comparators evaluated in an open-label, randomized crossover confinement AL study. The confinement design was adapted from previous ambulatory studies of Vuse Solo (G1 cartridge design) and included product familiarization sessions before each four-hour test session in which subjective measures, nicotine pharmacokinetics (PK), and physiological endpoints were assessed following a single 10-min ad libitum product use session. Product liking, intent to use again, suppression of urge to smoke, and nicotine PK were lower after use of Vuse Solo compared to cigarettes and higher after use of Vuse Solo compared to nicotine gum. No significant differences in blood pressure or heart rate were observed between the products pre- to post-product use. These data reinforce previous research and provide the scientific evidence to support regulatory decisions demonstrating that Vuse Solo has an AL profile lower than that of combustible cigarettes but higher than that of nicotine gum and, therefore, may be a suitable replacement for cigarette smoking for some adult smokers.

A Close Look at Vaping in Adolescents and Young Adults in the United States

Vaping by adolescents and young adults is a legitimate concern as there is a risk that some may start smoking and that electronic cigarette (EC) use may have adverse effects in the developing lungs of adolescents. This commentary provides updated information on vaping patterns among adolescents and young adults in the United States, as well as the impact of EC usage on respiratory health. EC use has surged greatly among high school students and young adults over the last decade but fortunately has declined significantly since its peak in 2019. During the same time period, smoking rates have constantly fallen to new low record levels. These trends argue against EC use as a gateway to smoking. Most EC usage is infrequent and unlikely to increase a person's risk of negative health consequences. Furthermore, the majority of EC usage has happened among those who have previously smoked. There is a dearth of data on the long-term health implications of EC usage in adolescents and young adults. We do not know whether short-term or intermittent use of EC in youth can lead to negative health outcomes in adulthood, and long-term high-quality studies in well-defined groups are needed. Although vaping has been linked to respiratory symptoms, they tend to be transient and of uncertain significance. This commentary provides up-to-date information so health care providers can give objective and responsible medical advice on EC usage.

A Decision-Theoretic Public Health Framework for Heated Tobacco and Nicotine Vaping Products

Markets for nicotine vaping products (NVPs) and heated tobacco products (HTPs) have grown as these products became positioned as harm-reduction alternatives to combusted tobacco products. Herein, we present a public health decision-theoretic framework incorporating different patterns of HTP, NVP, and cigarette use to examine their impacts on population health. Our framework demonstrates that, for individuals who would have otherwise smoked, HTP use may provide public health benefits by enabling cessation or by discouraging smoking initiation and relapse. However, the benefits are reduced if more harmful HTP use replaces less harmful NVP use. HTP use may also negatively impact public health by encouraging smoking by otherwise non-smokers or by encouraging initiation or relapse into smoking. These patterns are directly influenced by industry behavior as well as public policy towards HTPs, NVPs, and cigarettes. While substantial research has been devoted to NVPs, much less is known about HTPs. Better information is needed to more precisely define the health risks of HTPs compared to cigarettes and NVPs, the relative appeal of HTPs to consumers, and the likelihood of later transitioning to smoking or quitting all products. While our analysis provides a framework for gaining that information, it also illustrates the complexities in distinguishing key factors.

Cigarette Smoke Extract, but Not Electronic Cigarette Aerosol Extract, Inhibits Monoamine Oxidase in vitro and Produces Greater Acute Aversive/Anhedonic Effects Than Nicotine Alone on Intracranial Self-Stimulation in Rats

Conventional tobacco cigarettes appear to have greater abuse liability than non-combusted products such as electronic cigarettes (ECs) and nicotine replacement therapy (NRT). This may be due to the higher levels of behaviorally active non-nicotine constituents [e.g., monoamine oxidase (MAO) inhibitors such as β-carbolines] in cigarette smoke (CS) compared to non-combusted products. To evaluate this hypothesis, the current studies compared the relative abuse liability of CS and EC aerosol extracts containing nicotine and a range of non-nicotine constituents to that of nicotine alone (NRT analog) using intracranial self-stimulation (ICSS) in rats. Effects of formulations on brain MAO activity in vitro and ex vivo were also studied to evaluate the potential role of MAO inhibition in the ICSS study. CS extract contained higher levels of several behaviorally active non-nicotine constituents (e.g., the β-carbolines norharmane and harmane) than EC extract. Nicotine alone reduced ICSS thresholds at a moderate nicotine dose, suggesting a reinforcement-enhancing effect that may promote abuse liability, and elevated ICSS thresholds at a high nicotine dose, suggesting an aversive/anhedonic effect that may limit abuse liability. CS extract elevated ICSS thresholds to a greater degree than nicotine alone at high nicotine doses. Effects of EC extract on ICSS did not differ from those of nicotine alone. Finally, CS extract significantly inhibited MAO-A and MAO-B activity in vitro, whereas EC extract and nicotine alone did not. None of the formulations inhibited MAO measured ex vivo. These findings indicate greater acute aversive/anhedonic effects for CS extract compared to nicotine alone, suggesting lower abuse liability. Although confirmation of our findings using other dosing regimens, preclinical addiction models, and tobacco product extracts is needed, these findings suggest that the centrally-mediated effects of MAO inhibitors and other non-nicotine constituents may not account for the greater abuse liability of cigarettes compared to non-combusted products. Nonetheless, identifying the specific constituent(s) mediating the effects of CS extracts in this study could help clarify mechanisms mediating tobacco addiction and inform FDA product standards.

Influence of Flavors and Nicotine Concentration on Nicotine Dependence in Adolescent and Young Adult E-Cigarette Users

Objective: The objective of this study is to examine the relationships between e-cigarette flavors, nicotine concentration, and their interaction on measures of nicotine dependence.Methods: Survey data are drawn from a cross-sectional convenience sample of past 30-day e-cigarette users aged 15 to 24 years (N = 2037) collected between October 2020 and November 2020. Participants were asked to provide information about the e-cigarette products they used most regularly. Only those with available information on flavors (fruit, mint, menthol/ice, and tobacco), nicotine concentration (0-2.9%, 3-4.9%, and 5% or greater), and time to first vape after waking (within 30 minutes, greater than 30 minutes) were included in analyses (N = 1430). Generalized linear regression models were used with log link and binary distribution to assess the relationship between flavors, nicotine concentration, and nicotine dependence. Effect modification by nicotine concentration was assessed using an interaction term for flavors by nicotine concentration. Models were adjusted for age, race/ethnicity, gender, and financial situation.Findings: Fruit, mint, and menthol flavor user groups had a very similar dose-response relationship between nicotine concentration and prevalence of vaping within 30 minutes. These groups showed that the prevalence of vaping within 30 minutes gradually increased as nicotine concentration increased. Meanwhile, tobacco flavor user groups demonstrated a decrease in prevalence of vaping within 30 minutes, as nicotine concentration increased.Conclusion: Results highlight the need for understanding how e-cigarette product characteristics like flavors and nicotine concentration can facilitate nicotine dependence to e-cigarettes. Findings suggest that comprehensive e-cigarette product regulation of all flavors and reducing nicotine concentration will help to reduce the risk for nicotine dependence among young people.

Intentions and Attempts to Quit JUUL E-Cigarette Use: The Role of Perceived Harm and Addiction

Introduction

Research on electronic cigarette (e-cigarette) quit intentions and attempts is limited despite the potential health benefits of quitting, especially for long-term users. The current study aimed to investigate perceptions of harm and addictiveness and tobacco use characteristics associated with quit variables among users of a popular e-cigarette brand, JUUL.

Methods

We surveyed 301 US adult JUUL users on their tobacco use characteristics, perceptions of JUUL harm and addictiveness, and quit variables at 3 time points, from July 2019 to April 2020. We used logistic regression models to assess demographic characteristics, smoking characteristics, and perceptions of JUUL harm and addictiveness as correlates of e-cigarette quit intentions, attempts, importance, and confidence.

Results

Twenty-three percent of the sample had intentions to quit using JUUL within the year, and 22.6% reported making a lifetime quit attempt. The average rating of quit importance was 4.1 and quit confidence was 5.8 on a Likert scale of 1 to 10. More than 90% of the sample indicated that JUUL was at least moderately addictive, whereas less than one-quarter indicated that JUUL was as harmful or more harmful than smoking. Higher levels of perceived JUUL addictiveness were associated with more quit intentions, attempts, and importance. Higher levels of perceived JUUL harm compared with smoking were associated with more quit importance.

Conclusion

Our findings suggest that a small proportion of adult JUUL users are interested in quitting. Self-reported perceptions of JUUL’s addiction potential may be related to more quit attempts. Findings highlight the need for evidence-based information on e-cigarette addictiveness and effective strategies for cessation.

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.

Factors associated with past-year attempts to quit e-cigarettes among current users: Findings from the Population Assessment of Tobacco and Health Wave 4 (2017-2018)

Over 10 million adults report use of electronic nicotine delivery systems (ENDS), with approximately 3.6 million reporting daily use. Even as the popularity of ENDS has increased, both as an available nicotine delivery system and an alternative to combustible cigarette smoking, few studies to date have examined ENDS cessation interest and related behaviors among ENDS users. The current study aimed to describe past year attempts to quit ENDS among current users and to investigate ENDS use / user characteristics associated with unsuccessful attempts to quit in the past year among adult, current, established ENDS users using data from the Population Assessment of Tobacco and Health (PATH) Study Wave 4. Over 10 % of ENDS users reported an attempt to quit completely in the past year, and 60 % indicated future intention to quit completely. Higher nicotine dependence, lower-frequency ENDS use, and higher interest in quitting were associated with past year attempts to quit ENDS. The current study adds support to claims that many ENDS users plan to quit using ENDS someday and highlights the need for continued research on ENDS cessation.

Co-creating opportunities to incorporate cessation for electronic nicotine delivery systems in family medicine - a qualitative program evaluation

BACKGROUND

The number of Americans who use tobacco has decreased in the twenty-first century, but electronic nicotine delivery systems (ENDS) have increased the complexity of treating tobacco dependence. The experiences of 18 family medicine practices were explored and opportunities to improve ENDS cessation were co-created in this study.

METHODS

Eighteen family medicine practices were enrolled into an implementation project to incorporate ENDS cessation into their practice. The participants' experiences were explored throughout the project using an iterative qualitative approach. The research team provided technical assistance. Semi-structured group interviews and focus groups were held with participants at the beginning, middle, and end of the project to explore participants' experiences. The collective knowledge and experiences of participants, expert consultants and the research team were fused together to co-create opportunities to improve ENDS cessation.

RESULTS

Nine opportunities to improve ENDS cessation were identified in three larger categories. The first category was leading change. This included: creating a vision for change to establish buy-in from key stakeholders and educate health care professionals to improve their confidence to address ENDS. The second category was creating processes. This included: establishing criteria for screening and quality improvement for ENDS cessation; being specific when asking about ENDS; creating electronic health record systems to support incorporating ENDS cessation; using chart audits if electronic health records cannot support incorporating ENDS into tobacco cessation; and assigning roles and responsibilities to members of the clinical care team. The third category was assisting patients who use ENDS. This included: educating patients and their parents/caregivers about ENDS and their potential harms, avoiding dual use, and developing a plan to quit.

CONCLUSIONS

This study highlights challenges and opportunities for incorporating ENDS cessation into family medicine. The opportunities outlined here provide a practical approach which is rooted in the experiences of family physicians and their clinical care teams working to improve how they address ENDS and based on peer reviewed literature and expert input. Improving how ENDS are addressed in family medicine will require more than clinical expertise. It will also require leadership skills and the ability to create process improvements.

TRIAL REGISTRATION

Not applicable.

Vapers exhibit similar subjective nicotine dependence but lower nicotine reinforcing value compared to smokers

INTRODUCTION

E-cigarette use has increased rapidly over the last 10 years, mostly among smokers and ex-smokers. Although there may be some degree of dependency on nicotine via e-cigarette use, the nature of this dependency is poorly understood. The aim of this paper is to use tasks from behavioural economics to compare the value that smokers place on tobacco cigarettes to the value that vapers place on e-cigarettes.

METHOD

Exclusive current smokers (n = 25) and vapers (n = 20) attended one session where they completed the Cigarette/e-cigarette Dependence Scale, the Cigarette/e-cigarette Purchasing Task (CPT) and the Concurrent Choice Task (CCT). The CPT requires participants to indicate how many puffs of their chosen product they would purchase at increasing price points. The CCT requires participants to choose between earning a money point or a point towards a cigarette/e-cigarette after being presented with a neutral, money or cigarette/e-cigarette cue.

RESULTS

Overall scores on the self-report scales suggest a comparable level of dependency between smokers and vapers. The CPT revealed that vapers are more sensitive than smokers to escalating costs as consumption declined as costs increased. On the CCT, when primed with money, vapers showed a decrease in choosing e-cigarettes.

CONCLUSION

These findings suggest that, on behavioural economic tasks, tobacco cigarettes have a higher relative value than e-cigarettes. Vapers appear to place a lower limit on what they will spend to access e-cigarettes and more readily choose money over e-cigarette puffs when primed by money cues.

Nicotine Dependence in Dual Users of Cigarettes and E-Cigarettes: Common and Distinct Elements

INTRODUCTION

In a sample of dual users of cigarettes and electronic nicotine delivery systems (ENDS; e-cigarettes), we evaluated psychometric properties of ENDS versions of the Nicotine Dependence Syndrome Scale (NDSS), the brief Wisconsin Inventory of Smoking Dependence Motives (WISDM), and the Fagerström Test for Nicotine Dependence (FTND). Using the NDSS, we tested the hypothesis that there would be one common underlying factor of dependence across the cigarette and ENDS scales and other product-specific factors.

AIMS AND METHODS

Adult dual users (N = 404) completed baseline cigarette and ENDS versions of the NDSS, WISDM, and FTND, and biweekly surveys of their smoking and vaping. Analyses included bifactor modeling, which helps to identify both a general and product-specific factor for each item, and exploratory factor analyses of the combined cigarette and ENDS NDSS items and examinations of concurrent and predictive validity.

RESULTS

The bifactor model was not a good fit, suggesting the lack of one common underlying dependence factor. Factor analyses revealed separate, similar factors for both products, with only one factor (priority) showing overlap of cigarette and ENDS items. ENDS scales significantly predicted ENDS use over time, but not cigarette use. Cigarette scales did not predict ENDS use over time.

CONCLUSIONS

Although the cigarette and ENDS NDSS versions showed similar factor structure, there was not a primary common underlying factor reflecting drive or tolerance, but rather product-specific factors. The cigarette scales were not valid for predicting ENDS use. These results highlight the importance of separately assessing dependence for cigarettes and ENDS in dual users.

IMPLICATIONS

Although underlying dimensions of nicotine dependence may be similar for ENDS and cigarettes, separate, product-specific measures may be needed to understand differences in product-specific dependency and predict changes in use of each product over time.

Indicators of dependence and efforts to quit vaping and smoking among youth in Canada, England and the USA

OBJECTIVE

The current study examined indicators of dependence among youth cigarette smokers and e-cigarette users in Canada, England and the USA, including changes between 2017 and 2019.

METHODS

Data are from repeated cross-sectional online surveys conducted in 2017, 2018 and 2019 with national samples of youth aged 16-19 years, in Canada (n=12 018), England (n=11 362) and the USA (n=12 110). Measures included perceived addiction to cigarettes/e-cigarettes, frequency of experiencing strong urges to smoke/use an e-cigarette, plans to quit smoking/using e-cigarettes and past attempts to quit. Logistic regression models were fitted to examine differences between countries and changes over time.

RESULTS

The proportion of ever-users who vaped frequently was significantly higher in 2019 compared with 2017 for all outcomes in each country. Between 2017 and 2019, the proportion of past 30-day vapers reporting strong urges to vape on most days or more often increased in each country (Canada: 35.3%, adjusted OR (AOR) 1.69, 95% CI 1.20 to 2.38; England: 32.8%, AOR 1.55, 1.08 to 2.23; USA: 46.1%, AOR 1.88, 1.41 to 2.50), along with perceptions of being 'a little' or 'very addicted' to e-cigarettes (Canada: 48.3%, AOR 1.99, 1.44 to 2.75; England: 40.1%, AOR 1.44, 1.03 to 2.01; USA: 53.1%, AOR 1.99, 1.50 to 2.63). Indicators of dependence among smokers were consistently greater than e-cigarette users, although differences had narrowed by 2019, particularly in Canada and the USA.

CONCLUSIONS

Prevalence of dependence symptoms among young e-cigarette users increased between 2017 and 2019, more so in Canada and the USA compared with England. Dependence symptom prevalence was lower for e-cigarettes than smoking; however, the gap has narrowed over time.

An Open-Label, Randomized, Controlled, Crossover Study to Assess Nicotine Pharmacokinetics and Subjective Effects of the JUUL System with Three Nicotine Concentrations Relative to Combustible Cigarettes in Adult Smokers

Introduction

This randomized, open-label, crossover clinical study evaluated nicotine pharmacokinetics (PK) and subjective effects of the JUUL System (JS; Juul Labs, Inc.) with three nicotine concentrations compared to the usual brand (UB) cigarettes in 24 adult smokers.

Methods

At five study visits, subjects used either the JS in 59 mg/mL, JS 18 mg/mL (two visits), and JS 9 mg/mL (all tobacco-flavored) or smoked their UB cigarette first during a controlled puffing sequence (CPS) and then ad libitum (5 min) use sessions. Blood samples were taken at specified timepoints for 60 min in each session. The modified Product Evaluation Scale assessed subjective effects 30-min post-use in the CPS session.

Results

Maximum plasma nicotine concentration (C_max-BL), total nicotine exposure (AUC_0-60-BL), and rate of plasma nicotine rise were significantly lower for all JS products compared to subjects' UB cigarette in CPS and ad libitum use sessions. In both use sessions these PK parameters were significantly higher for JS 59 mg/mL compared to 18 and 9 mg/mL. Subjective measures of cigarette craving relief and “Enough Nicotine” for JS 59 mg/mL did not differ significantly from UB cigarettes, but JS 18 and 9 mg/mL were rated significantly lower than JS 59 mg/mL and UB cigarettes.

Conclusions

Nicotine exposure and subjective relief were directly related to JS nicotine concentration: higher nicotine concentrations gave rise to significantly greater plasma nicotine levels and relief from craving. Heavier and more dependent smokers may require the greater nicotine delivery of JS 59 mg/mL to successfully transition away from cigarettes.

Implications

It has been suggested that electronic nicotine delivery systems (ENDS) and other alternative nicotine delivery products that more closely mimic the nicotine pharmacokinetics (PK) of cigarettes may facilitate smokers transitioning away from cigarettes. We examined nicotine PK and subjective effects of JUUL System (JS) ENDS with three nicotine concentrations (59, 18 and 9 mg/mL) compared to combustible cigarettes. Nicotine delivery from JS ENDS was nicotine concentration dependent, with higher nicotine concentrations giving rise to higher nicotine exposure. These findings suggest that heavier and more dependent smokers may require ENDS with nicotine concentrations greater than 20 mg/mL to successfully transition away from cigarettes.

Kicking the habit is hard: A hybrid choice model investigation into the role of addiction in smoking behavior

Use of choice models is growing rapidly in tobacco research. These models are being used to answer key policy questions. However, certain aspects of smokers' choice behavior are not well understood. One such feature is addiction. Here, we address this issue by modeling data from a choice experiment on the US smokers. We model addiction using a latent variable. We use this latent variable to understand the relationship between choices and addiction, giving attention to nicotine levels. We find that more addicted smokers have stronger preferences for cigarettes and are unwilling to switch to e-cigarettes. Addicted smokers value nicotine in tobacco products to a much greater extent than those that are less addicted. Lastly, we forecast short-term responses to lowering nicotine levels in cigarettes. The results suggest that current nicotine-focused policies could be effective at encouraging addicted smokers to less harmful products and lead to substantial public health gains.

Chronic exposure to cigarette smoke extract upregulates nicotinic receptor binding in adult and adolescent rats

Heavy smokers display increased radioligand binding of nicotinic acetylcholine receptors (nAChRs). This "upregulation" is thought to be a contributing factor to tobacco dependence. Although cigarette smoke contains thousands of constituents that can contribute to nicotine dependence, it is not well understood whether non-nicotine constituents contribute to nAChR upregulation. In this study, we used an aqueous cigarette smoke extract (CSE), which contains nicotine and soluble constituents of cigarette smoke, to induce nAChR upregulation in adult and adolescent rats. To do this, male rats were exposed to nicotine or CSE (1.5 mg/kg/day nicotine equivalent, intravenously) daily for ten days. This experimental procedure produces equivalent levels of brain and plasma nicotine in nicotine- and CSE-treated animals. We then assessed nAChR upregulation using quantitative autoradiography to measure changes in three nAChR types. Adolescents were found to have consistently greater α4β2 nAChR binding than adults in many brain regions. Chronic nicotine exposure did not significantly increase nAChR binding in any brain region at either age. Chronic CSE exposure selectively increased α4β2 nAChR binding in adolescent medial amygdala and α7 binding in adolescent central amygdala and lateral hypothalamus. CSE also increased α3β4 nAChR binding in the medial habenula and interpeduncular nucleus, and α7 binding in the medial amygdala, independent of age. Overall, this work provides evidence that cigarette smoke constituents influence nAChR upregulation in an age-, nAChR type- and region-dependent manner.

Abuse liability assessment of the JUUL system in four flavors relative to combustible cigarette, nicotine gum and a comparator electronic nicotine delivery system among adult smokers

BACKGROUND

The abuse liability of the JUUL System (JS) in four flavors were evaluated compared to combustible cigarettes, nicotine gum, and a comparator electronic nicotine delivery system (ENDS) with pharmacokinetics (PK) and subjective effects.

METHODS

Adult smokers (N = 66; 50.0 % female; mean age = 41.1; 63.6 % white) completed a 7-arm within-subjects cross-over product-use study while confined to a clinical laboratory. Participants used JS in four flavors (Virginia Tobacco, Mango, Mint, Creme, [5.0 % nicotine; 59 mg/mL]), their usual brand (UB) cigarette, a comparator ENDS (VUSE Solo; 4.8 % nicotine, tobacco-flavor), and mint nicotine gum (4 mg) under controlled use conditions. After each product use, nicotine PK and subjective effects were assessed.

RESULTS

Maximum plasma nicotine levels (Cmax-BL), rate of plasma nicotine rise, overall nicotine exposure (AUC0-60-BL), and subjective liking and satisfaction of JS were significantly lower than UB cigarettes. These parameters were generally greater for JS than nicotine gum; the comparator ENDS was somewhat lower but within the range of JS. Nicotine PK did not differ among the Mint, Mango, and Virginia Tobacco JS flavors. Mint and Mango were rated as more satisfying than Virginia Tobacco and Creme.

CONCLUSIONS

Controlled use of JS among adult smokers resulted in nicotine delivery, product liking, and satisfaction that were less than that of combustible cigarettes but generally greater than nicotine gum. These results support the conclusion that JS has lower abuse liability than combustible cigarettes, higher abuse liability than nicotine gum, and may provide sufficient nicotine delivery and satisfying effects to support substitution for combustible cigarettes among adult smokers.

Dependence on e-cigarettes and cigarettes in a cross-sectional study of US adults

BACKGROUND AND AIMS

Cigarette smoking often results in nicotine dependence. With use of electronic cigarettes as an alternative source of nicotine, it is important to assess dependence associated with e-cigarette use. This study assesses dependence among current and former adult e-cigarette users on cigarettes and e-cigarettes, compared with dependence on cigarettes.

DESIGN

Cross-sectional data from the Population Assessment of Tobacco and Health (PATH) study from 2013-2016. Psychometrically assessed dependence was compared for cigarettes and e-cigarettes among current and former exclusive and dual users of the products and among e-cigarette users who had and had not recently stopped smoking. Setting A population-based representative sample of US adults. Participants Participants were 13 311 US adults (18+) in Waves 1-3 of PATH reporting current established smoking, current use of e-cigarettes, or stopping use of either product in the past year who were administered dependence assessments for cigarettes and/or e-cigarettes. Measurements A 16-item scale assessing tobacco dependence (on a 1-5 scale), previously validated for assessment and comparison of dependence on varied tobacco products, including cigarettes and e-cigarettes, with a variation assessing residual dependence among users who stopped in the past year. Findings Among current users, dependence on e-cigarettes was significantly lower than dependence on cigarettes, in within-subjects comparisons among dual users of both e-cigarettes and cigarettes (1.58 [SE = 0.05] vs. 2.76 [0.04]), P < 0.0001), and in separate groups of e-cigarette users and cigarette smokers (1.95 [0.05] vs. 2.52 [0.02], P < 0.0001), and among both daily and non-daily users of each product. Among former users, residual symptoms were significantly lower for e-cigarettes than cigarettes, both among former dual users (1.23 [0.07] vs. 1.41 [0.06], P < 0.001) and among users of one product (1.28 [0.03] vs. 1.53 [0.03], P < 0.0001). The highest level of e-cigarette dependence was among e-cigarette users who had stopped smoking (2.17 [0.08]). Conclusion Use of e-cigarettes appears to be consistently associated with lower nicotine dependence than cigarette smoking.

Developmental Trajectories of Tobacco/Nicotine and Cannabis Use and Patterns of Product Co-use in Young Adulthood

Introduction

Concurrent co-use of tobacco/nicotine and cannabis (T/C) products is common among young people and may increase risks for negative health and psychosocial outcomes, but little is known about developmental patterns of T/C co-use. This study aimed to identify distinct trajectory classes of concurrent T/C co-use from ages 16 to 21 and compare groups on T/C co-use behaviors in young adulthood.

Methods

Participants (n = 2497) reported T/C use on annual online surveys from 2015 to 2019 (ages 16-22). We used parallel process growth mixture models to model simultaneous trajectories of past-month cigarette, e-cigarette, smokeless tobacco, and cannabis use and identify latent classes of T/C trajectories. Classes were then compared on types and number of T/C products used and types of T/C co-use in young adulthood.

Results

Models revealed 4 T/C classes: Low/No T/C Use, Early Concurrent T/C Co-use, Late Concurrent T/C Co-use, and Tobacco Quitters/Cannabis Maintainers. Compared to other classes, the Early Concurrent T/C Co-use group-individuals with rapid progression to concurrent T/C co-use during adolescence-were more likely to report poly-tobacco use, poly-cannabis use, same-occasion sequential T/C co-use and T/C co-administration (ie, mixing T/C) of both combustible and vaping products in young adulthood.

Conclusion

Early progression to concurrent T/C co-use in adolescence is prospectively linked to poly-product use and co-use of T/C products in young adulthood. Prevention efforts targeting co-use of T/C products in adolescence may help to reduce riskier patterns of T/C use and co-use in young adulthood.