Development of a questionnaire for assessing dependence on electronic cigarettes among a large sample of ex-smoking E-cigarette users

The association between smoking/vaping habits and self-reported respiratory symptoms

BACKGROUND

Smoking is well known for its harmful effect on the respiratory system, but whether vaping is less harmful is unknown. Therefore, the aim of this study was to assess the association of smoking/vaping habits with self-reported respiratory symptoms in vapers and cigarette smokers.

METHODS

An online survey was developed and shared on different vaping and smoking social media platforms and communities.

RESULTS

Out of the 891 respondents, 788 were vapers (77 pure vapers and 711 ex-smokers) and 103 were cigarette smokers. Smokers reported more frequently respiratory symptoms such as chest pain, wheezing and whistling, sputum production, cough, dry mouth, and smokers suffered from more shortness of breath, sore throat and disturbed sleep compared to vapers. The self-reported respiratory symptoms in vapers were mainly related to the nicotine strength of the product and number of puffs per use. There were no significant differences between pure vapers and vapers who were ex-smokers.

CONCLUSION

Self-reported severe respiratory symptoms were less frequent in vapers than smokers, irrespective of their smoking history. This suggests that vaping is less harmful than cigarette smoking.

Predictors of attrition in a randomized controlled trial of an electronic nicotine delivery system among people interested in cigarette smoking reduction

BACKGROUND

Mitigating attrition is a key component to reduce selection bias in longitudinal randomized controlled trials (RCTs). Few studies of electronic nicotine delivery systems (ENDS) allow for the examination of long-term retention. This analysis explores the relationship between attrition, baseline measures, and condition assigned for a RCT involving ENDS differing in nicotine delivery over a 24-week intervention period.

METHODS

Participants (N = 520) who smoked ≥10 cigarettes per day [CPD] for ≥1 year and reported interest in reducing but not quitting were randomized to 1 of 4 conditions: an ENDS containing 0, 8, or 36 mg/ml liquid nicotine (administered double-blind) or a cigarette-shaped plastic tube. Cox proportional hazards regression models were fit to examine attrition over time and predictors of attrition including baseline characteristics and condition. A stepwise approach was used to determine the final model; alpha was set at 0.05.

RESULTS

Attrition did not differ significantly by condition (223/520), and most (69%) were lost-to-follow-up. Only age, education level, and household income were significantly predictive of attrition. For every additional year of age, attrition risk fell by 3%. Holding a bachelor's degree or higher was associated with reduced attrition risk. Those with the lowest income (<$10 K) were more likely to be withdrawn compared to those earning $10 K-39 K, and those with the highest income ($100 K+) were more likely to be withdrawn compared with the latter bracket and those earning $70-99 K.

CONCLUSION

ENDS nicotine content did not drive differential attrition in this trial, and targeted retention efforts are needed for specific subgroups. Trial Registration #: NCT02342795.

Outcomes of a Comprehensive Mobile Vaping Cessation Program in Adults Who Vape Daily: Cohort Study

BACKGROUND

In the United States, e-cigarettes, or vapes, are the second most-commonly used tobacco product. Despite abundant smartphone app-based cigarette cessation programs, there are few such programs for vaping and even less supporting data.

OBJECTIVE

This exploratory, prospective open-label, single-arm, remote, initial cohort study of the Pivot vaping cessation program assessed enrollment and questionnaire completion rates, participant engagement and retention, changes in attitudes toward quitting vaping, changes in vaping behavior, and participant feedback. The aim was to establish early data in each of these areas to inform program improvements and future study design.

METHODS

U.S. adults aged ≥ 21 years who vape daily, report ≥ 5 vape sessions per day, and plan to quit vaping in the next 6 months were recruited online. Participants completed an online screening form, screening call, electronic informed consent, registration, and onboarding before beginning Pivot. Data were self-reported via app and web-based questionnaires. Outcomes focused on engagement and retention (i.e., weeks in the program, number of Pivot app openings, number of messages sent to coach); vaping attitudes (i.e., success to quit, difficulty to stay quit); vaping behavior (i.e., quit attempts, Penn State Electronic Cigarette Dependence Index, 7- and 30-day point prevalence abstinence [PPA], continuous abstinence [defined as ≥ 7-day PPA at 12 weeks + 30-day PPA at 26 weeks + 0 vaping sessions since 12 weeks]); and participant feedback.

RESULTS

Seventy-three participants completed onboarding (intention-to-treat [ITT] sample); 68/73 (93%) completed the 12- and 26-week questionnaires (completer samples). On average, participants were active in Pivot for 13.8 (SD 7.3) weeks, had 87.3 (SD 99.9) app sessions, and sent 37.6 (SD 42.3) messages to their coach over 26 weeks. Success to quit and difficulty to stay quit (scale 1-10) improved from baseline to 12 weeks: 4.9 (SD 2.9) to 7.0 (SD 3.0) and 4.0 (SD 2.8) to 6.2 (SD 3.1), respectively; both P < .001. Most participants (64/73, 88%) made ≥ 1 quit attempt. At 26 weeks, ITT 7-day PPA, 30-day PPA and continuous abstinence rates were: 35/73 (48%), 33/73 (45%), and 22/73 (30%), respectively. Thirty-three participants did not achieve 7-day PPA at 26 weeks; their mean Penn State Electronic Cigarette Dependence Index score decreased from baseline (13.9, SD 3.1) to 26 weeks (10.8, SD 4.5) (mean change -3.2, SD 3.9, P < .001); almost half (16/33, 48%) had improvement in e-cigarette dependence category. At 2 weeks, 51/71 (72%) reported using Pivot increased their motivation to quit vaping; at 4 weeks, 55/70 (79%) reported using Pivot decreased the amount they vape per day.

CONCLUSIONS

In this first evaluation of Pivot in adult daily vapers, questionnaire completion rates were >90%, average program engagement duration was approximately 14 weeks and most participants reported increased motivation to quit vaping. These and early cessation outcomes herein suggest a role for Pivot in vaping cessation and will inform associated future study and program improvements.

CLINICALTRIAL

ClinicalTrials.gov NCT05642598; https://clinicaltrials.gov/study/NCT05642598.

Understanding the motivational mechanisms for smoking and vaping among dual users and exclusive smokers

BACKGROUND

Understanding the motivational processes that influence e-cigarette use in a laboratory setting may help elucidate mechanisms that support long-term ecigarette use, which could have significant clinical and public health consequences.

METHODS

Secondary analyses were conducted on data from exclusive smokers (N=47) and dual users (N=88) who underwent a laboratory ad lib use session. Participants were given 10minutes to smoke (exclusive smokers) or vape (dual users) as much as they wanted. Withdrawal was assessed pre- and post-use. Smoking and vaping behavior was coded from session videos. Person-level predictors included cigarette/ecigarette craving-relief expectancies, demographics, and cigarette/e-cigarette use and dependence. Smoking and vaping status was assessed at Year 1 using self-reported 30-day point prevalence. Data were analyzed using general linear models and logistic regressions.

RESULTS

Both groups reported reductions in withdrawal after product use, including cigarette craving. Baseline e-cigarette craving-relief expectancies, pre-session ecigarette craving, heaviness of e-cigarette use, and relative e-cigarette dependence were significant univariate predictors of continued vaping in dual users at Year 1 (ORs>1.04, ps<.05). Dual users and exclusive smokers did not differ on use behavior (i.e., average number of puffs, ps>.16).

CONCLUSIONS

E-cigarette use alleviated withdrawal, including cigarette and e-cigarette craving, in dual users. Laboratory use behavior did not differ between dual users using e-cigarettes and exclusive smokers using cigarettes. Greater e-cigarette craving-relief expectancies, e-cigarette craving, heaviness of e-cigarette use, and morning product use pattern ('relative dependence') may reflect mechanisms that sustain e-cigarette use.

A Vaping Cessation Text Message Program for Adolescent E-Cigarette Users: A Randomized Clinical Trial

Importance

E-cigarettes are the most commonly used tobacco product among adolescents. Despite known harms of nicotine exposure among teens, there are no empirically tested vaping cessation interventions.

Objective

To compare the effectiveness of a text message program for nicotine vaping cessation among adolescents with assessment-only control.

Design, Setting, and Participants

A parallel, 2-group, double-blind, individually randomized clinical trial with follow-ups at 1 and 7 months after randomization was conducted from October 1, 2021, to October 18, 2023. Participants were recruited via social media ads; the intervention was delivered via text message; and assessments were completed online or by telephone. Eligible individuals were US residents aged 13 to 17 years who reported past 30-day e-cigarette use, were interested in quitting within 30 days, and owned a mobile phone with an active text message plan. To optimize study retention, all participants received monthly assessments via text message about e-cigarette use.

Interventions

Assessment-only controls (n = 744) received only study retention text messages. Intervention participants (n = 759) also received an automated, interactive text message program for vaping cessation that delivers cognitive and behavioral coping skills training and social support.

Main Outcomes and Measures

The primary outcome was self-reported 30-day point-prevalence abstinence from vaping at 7 months analyzed as intention-to-treat, with missingness coded as vaping.

Results

Among n = 1503 adolescents randomized, average age was 16.4 (SD, 0.8) years. The sample was 50.6% female, 42.1% male, and 7.4% nonbinary/other; 10.2% Black/African American, 62.6% White, 18.5% multiracial, and 8.7% another race; 16.2% Hispanic; 42.5% sexual minority; and 76.2% vaped within 30 minutes of waking. The 7-month follow-up rate was 70.8%. Point-prevalence abstinence rates were 37.8% (95% CI, 34.4%-41.3%) among intervention participants and 28.0% (95% CI, 24.9%-31.3%) among control participants (relative risk, 1.35 [95% CI, 1.17-1.57]; P < .001). No baseline variables moderated the treatment-outcome relationship. There was no evidence that adolescents who quit vaping transitioned to combustible tobacco products.

Conclusions and Relevance

A tailored, interactive text message intervention increased self-reported vaping cessation rates among adolescents recruited via social media channels.

Trial Registration

ClinicalTrials.gov Identifier: NCT04919590.

The prospective relationship between a-priori intentions for and patterns of e-cigarette use among adults who smoke cigarettes

BACKGROUND

Electronic (e-)cigarettes may help adult cigarette smokers achieve cigarette cessation, depending on patterns of e-cigarette use. Among cigarette smokers who do not use e-cigarettes, it is unclear if and how a-priori intentions for use are related to uptake patterns. Longitudinal studies have focused on established e-cigarette users or adolescent and young adult populations exclusively.

METHODS

Within a nationwide randomized clinical trial (N = 638), adult cigarette smokers not currently using e-cigarettes were randomized (2:1) to receive (or not) one-month sampling of e-cigarettes. An exploratory factor analysis (EFA) was performed on an established 15-item measure assessing a-priori intentions for e-cigarette use to identify latent variables. Among those receiving e-cigarette products, regression models examined relationships between intentions and: 1) uptake (yes/no), 2) frequency (number of days per week), and 3) amount (puffing episodes per day) of e-cigarette use at one-month follow-up.

RESULTS

Two factors emerged from the EFA: 1) cigarette-related intentions (e.g., cigarette cessation, no smell) and 2) novel appeal of e-cigarettes (e.g., flavors). Three items remained and were treated as separate intentions: "feels like cigarette smoking", "curiosity", and "affordability". In the final multivariable models, "feel like cigarette smoking" predicted more frequent e-cigarette use (β = 0.187, SE = 0.086, p = 0.03); however, none of the five factors/intentions were significantly associated with uptake or amount of use.

CONCLUSIONS

For adult cigarette smokers not currently using e-cigarettes, a-priori intentions for using e-cigarettes might not be predictive of if or how these products will be used in the future, suggesting that motives may not drive use behavior.

Kick Vaping: Feasibility, acceptability, and preliminary impact of a vaping cessation text messaging intervention for Latino young adults

OBJECTIVE

To assess the feasibility, acceptability, and preliminary impact of Kick Vaping among Latino young adults.

METHODS

Forty Latino young adults (ages 18 to 25) who were currently vaping received Kick Vaping, a vaping cessation text messaging intervention available in English and Spanish. Feasibility was measured by the eligibility, enrollment, and follow-up rates. Acceptability was measured by overall satisfaction with the intervention. Preliminary impact was measured by self-reported 7-day point prevalence abstinence and changes in self-efficacy.

RESULTS

Two hundred three individuals were identified, 61 were assessed for eligibility, and 55 were eligible. Forty individuals consented to participate and were enrolled in Kick Vaping. At baseline, most participants used disposable devices (70%), vaped daily (97.5%), had low (37.5%) or medium (35.0%) e-cigarette dependence, and had attempted to quit in the past year (72.5%). At Month 3, the follow-up rate was 90% (36/40). Treating those lost to follow-up as participants who continued vaping, 75% (30/40) of participants self-reported 7-day point prevalence abstinence. Self-efficacy mean scores significantly increased from 30.65 (SD 8.07) at baseline to 50.11 (SD 10.57) at follow-up (p < 0.01). Most participants (88.9%, 32/36) reported being satisfied/extremely satisfied with Kick Vaping.

CONCLUSION

It is feasible to recruit and retain Latino young adults in a vaping cessation text messaging intervention. Kick Vaping generated high satisfaction among Latino young adults, significantly increased self-efficacy, and resulted in a notable vaping cessation rate at Month 3. Additional testing in a randomized controlled trial is warranted to assess the efficacy of the intervention.

E-Cigarette Use Behavior and Expectancies Among Sexual Minority and Heterosexual College Student E-Cigarette Users

Background: College students who identify as a sexual minority (i.e., lesbian, gay, bisexual, or other sexual orientation) are at higher risk for e-cigarette use than their heterosexual or "straight" peers. However, little is known about factors, such as e-cigarette outcome expectancies, that might influence these differences in prevalence rates. Therefore, the current study examined differences between heterosexual and sexual minority college student e-cigarette users in terms of days of past-month e-cigarette use, e-cigarette dependence, and e-cigarette outcome expectancies. A secondary aim of the study was to examine whether outcome expectancies served as an explanatory mechanism in the association between sexual minority status and e-cigarette use frequency and dependence. Methods: Participants were heterosexual (n = 90; Mage = 19.65, SD = 2.70; 76.7% female; 77.8% White) and sexual minority (n = 44; Mage = 20.02, SD = 2.18; 68.2% female; 90.9% White) college student e-cigarette users who completed self-report measures. Results: Students who identified as a sexual minority reported greater e-cigarette dependence, more frequent past 30-day use, and greater negative consequences and positive reinforcement e-cigarette outcome expectancies. Follow-up mediation analyses indicated a significant indirect effect of sexual minority status on both days of past-month e-cigarette use and e-cigarette dependence through expectancies for negative consequences and positive reinforcement. Conclusions: These findings suggest that positive reinforcement and negative consequences outcome expectancies may be contributing to the disparities in e-cigarette use among college students who identify as a sexual minority and could be useful targets for cessation interventions for this population.

E-cigarette use reasons and associated e-cigarette use dependence among college students: A longitudinal examination

OBJECTIVE

Previous studies have established an understanding of reasons for e-cigarette use and associated e-cigarette use patterns such as use frequency, yet the critical extension to associated e-cigarette dependence outcome remains under-researched. This study used longitudinal data to examine whether the reasons for e-cigarette use predict a higher/lower level of e-cigarette dependence.

METHODS

This study recruited college students who were current e-cigarette users from Fall 2019 to Fall 2020 (four semesters) at three public universities in the Midwest and South of the U.S. Those who participated for at least two semesters were included (N = 366). Data were collected using a structured questionnaire. E-cigarette use dependence was assessed using the Penn State Electronic Cigarette Dependence Index. A linear mixed model with a random intercept and a random slope was conducted to examine the longitudinal association between reasons for e-cigarette use and dependence, controlling for demographics and other covariates.

RESULTS

Participants who used e-cigarettes for relaxation (β = 0.63, p < 0.05) and due to their good taste (β = 0.63, p < 0.05) had a higher level of e-cigarette dependence. Participants using e-cigarettes for experimental purposes had a lower level of e-cigarette dependence (β = -1.21, p < 0.01).

CONCLUSIONS

These findings highlight the importance of addressing e-cigarette use reasons and their relationship to e-cigarette dependence. Prevention and intervention efforts aimed at developing more effective strategies should consider the various e-cigarette use reasons associated with dependence risks, such as enhancing awareness of the use dependence risk related to good taste of e-cigarettes and use for relaxation, as well as incorporating early screenings for use.

Cytisinicline for Vaping Cessation in Adults Using Nicotine E-Cigarettes: The ORCA-V1 Randomized Clinical Trial

Importance

The prevalence of e-cigarette use among US adults, especially young adults, is rising. Many would like to quit vaping nicotine but are unable to do so. Cytisinicline, a plant-based alkaloid, targets nicotinic acetylcholine receptors, reduces nicotine dependence, and helps adults to stop smoking cigarettes. Cytisinicline may also help e-cigarette users to quit vaping.

Objective

To determine the efficacy and safety of cytisinicline vs placebo to produce abstinence from e-cigarette use in adults seeking to quit vaping nicotine.

Design, Setting, and Participants

This double-blind placebo-controlled randomized clinical trial compared 12 weeks of treatment with cytisinicline vs placebo, with follow-up to 16 weeks. It was conducted from July 2022 to February 2023 across 5 US clinical trial sites. A total of 160 adults who vaped nicotine daily, sought to quit, and did not currently smoke cigarettes were enrolled, and 131 (81.9%) completed the trial.

Intervention

Participants were randomized (2:1) to cytisinicline, 3 mg, taken 3 times daily (n = 107) or placebo (n = 53) for 12 weeks. All participants received weekly behavioral support.

Main Outcomes and Measures

Biochemically verified continuous e-cigarette abstinence during the last 4 weeks of treatment (weeks 9-12; primary outcome) and through 4 weeks posttreatment (weeks 9-16; secondary outcome). Missing outcomes were counted as nonabstinence.

Results

Of 160 randomized participants (mean [SD] age, 33.6 [11.1] years; 83 [51.9%] female), 115 (71.9%) formerly smoked (≥100 lifetime cigarettes). Continuous e-cigarette abstinence in cytisinicline and placebo groups occurred in 34 of 107 participants (31.8%) vs 8 of 53 participants (15.1%) (odds ratio, 2.64; 95% CI, 1.06-7.10; P = .04) at end of treatment (weeks 9-12) and in 25 of 107 participants (23.4%) vs 7 of 53 participants (13.2%) during weeks 9 to 16 (odds ratio, 2.00; 95% CI, 0.82-5.32; P = .15). There was no evidence, based on nonsignificant interactions, that cytisinicline efficacy differed in subgroups defined by demographic characteristics, vaping pattern, e-cigarette dependence, or smoking history. Cytisinicline was well tolerated, with 4 participants (3.8%) discontinuing cytisinicline due to an adverse event.

Conclusions and Relevance

In this randomized clinical trial, cytisinicline for 12 weeks, with behavioral support, demonstrated efficacy for cessation of e-cigarette use at end of treatment and was well tolerated by adults, offering a potential pharmacotherapy option for treating nicotine e-cigarette use in adults who seek to quit vaping. These results need confirmation in a larger trial with longer follow-up.

Trial Registration

ClinicalTrials.gov Identifier: NCT05431387.

Combining app-based behavioral therapy with electronic cigarettes for smoking cessation: a study protocol for a single-arm mixed-methods pilot trial

BACKGROUND

Cigarette smoking remains a leading cause of preventable illness and death, underscoring the need for effective evidence-based smoking cessation interventions. Nuumi, a novel smoking cessation program integrating a digital behavioral therapy and an electronic cigarette, may provide a solution.

OBJECTIVE

To investigate the initial efficacy, acceptability and psychological outcomes of an evidence-based smoking cessation intervention comprised of a mobile phone app and an electronic cigarette among adults who smoke and who are motivated to quit.

METHODS

A prospective 6-month single-arm mixed-methods pilot study will be conducted. Seventy adults who smoke and who are motivated to quit will be recruited via web-based advertisements and flyers. Participants receive access to an app and an electronic cigarette with pods containing nicotine for temporary use of at least 3 months. The electronic cigarette is coupled with the app via Bluetooth, allowing for tracking of patterns of use. The behavioral therapy leverages evidence-based content informed by cognitive behavioral therapy and mindfulness-informed principles. Web-based self-report surveys will be conducted at baseline, at 4 weeks, at 8 weeks, at 12 weeks, and at 24 weeks post-baseline. Semi-structured interviews will be conducted at baseline and at 12 weeks post-baseline. Primary outcomes will be self-reported 7-day point prevalence abstinence from smoking at 12 weeks and 24 weeks. Secondary outcomes will include other smoking cessation-related outcomes, psychological outcomes, and acceptability of the nuumi intervention. Descriptive analyses and within-group comparisons will be performed on the quantitative data, and content analyses will be performed on the qualitative data. Recruitment for this study started in October 2023.

DISCUSSION

As tobacco smoking is a leading cause of preventable morbidity and mortality, this research addresses one of the largest health burdens of our time. The results will provide insights into the initial efficacy, acceptability, and psychological outcomes of a novel mobile health intervention for smoking cessation. If successful, this pilot may generate an effective intervention supporting adults who smoke to quit smoking. The results will inform feasibility of a future randomized controlled trial. Trial Registration German Clinical Trials Register DRKS00032652, registered 09/15/2023, https://drks.de/search/de/trial/DRKS00032652 .

Partial Nicotine Reduction and E-Cigarette Users' Puffing Behaviors Among Adults Aged 21 to 35 Years: A Randomized Crossover Clinical Trial

Importance

The advent of salt-based, high-nicotine electronic nicotine delivery systems [e-cigarettes] has contributed to their epidemic use among young people in the US, necessitating the need for policies to address the addictiveness of these products.

Objective

To evaluate the effect of partial nicotine reduction on new-generation e-cigarette users' puffing behaviors.

Design, Setting, and Participants

This randomized crossover clinical trial was conducted at the Clinical Research Lab for Tobacco Smoking at Florida International University in Miami between April 15, 2022, and October 17, 2023. Using a volunteering sampling method by distributing flyers and advertisements, current e-cigarette users (who preferred 5% nicotine concentration), aged 21 to 35 years, were included.

Intervention

In a crossover design, participants completed 2 sessions of the same product (JUUL or NJOY) that differed by nicotine concentration (3% [JUUL] or 2.4% [NJOY] and 5% [JUUL or NJOY]) in random order. In each session, participants vaped up to 60 minutes ad libitum, preceded by 12 hours of nicotine abstinence.

Main Outcomes and Measures

The primary outcomes were puffing topography parameters (eg, total session time, puffing time, total puffing number, interpuff interval, total inhaled volume, average puff volume, duration, and flow rate) measured during each session and plasma nicotine measured before and after each session.

Results

Among 735 participants who were approached for eligibility, 675 were excluded, and 10 did not complete session 2. Of the 50 remaining current e-cigarette users (mean [SD] age, 23 [3] years; 56% men), 23 (46%) were low nicotine dependent. The median topography parameters were significantly higher during the e-cigarette use sessions with 3% or 2.4% nicotine concentration compared with 5% nicotine concentration for 3 outcomes: puffing time (1.3 minutes [IQR, 0.3-9.4 minutes] vs 1.2 minutes [IQR, 0.2-5.6 minutes]; P = .02), puff duration (2.6 seconds [IQR, 0.8-6.9 seconds] vs 2.4 seconds [IQR, 0.4-6.6 seconds]; P = .02), and total inhaled volume (1990.0 mL [IQR, 279.0-24 400.0 mL] vs 1490.0 mL [IQR, 148.0-14 300.0 mL]; P = .05). The median plasma nicotine boost observed in the 5% nicotine concentration condition (0.0060 mg/L [IQR, 0.0001-0.0249 mg/L]) was significantly higher than that in the 3% or 2.4% session (0.0043 mg/L [IQR, 0.0008-0.0225 mg/L]) (P = .001). Additionally, deeper puffing (increased average puff duration and average puff volume) was observed in participants with higher nicotine dependence (1.42 seconds [95% CI, 1.12-1.80 seconds]; P = .03) and male users (1.38 mL [95% CI, 1.09-1.75 mL]; P = .04) in response to nicotine reduction.

Conclusions and Relevance

This randomized crossover clinical trial provides direct evidence that partial nicotine reduction in salt-based e-cigarettes was associated with acute compensatory puffing and the potential for increased exposure to toxicants. However, given the reduced nicotine delivery associated with nicotine reduction, the acute compensatory response observed in this study may not preclude a population benefit due to the marketing of less addictive products. These results suggest that at least for current e-cigarette users, partial nicotine reduction can lead to enhanced exposure to some toxicants in the short term.

Trial Registration

ClinicalTrials.gov Identifier: NCT05205382.

Differences in Attentional Bias Toward e-Cigarette Cues Between e-Cigarette Users and Nonusers

ABSTRACT

The use of electronic nicotine delivery systems (ENDS) has increased rapidly in recent years, particularly among young adults. There is a dearth of research on the cognitive factors that contribute to ENDS use. One of the possible cognitive mechanisms involved with addictive behavior is attentional bias (AB). AB can manifest as either facilitated attention engagement toward or delayed attention disengagement from a relevant stimulus. The purpose of this study was to examine the difference in AB toward ENDS-related cues between ENDS users and non-ENDS users. ENDS users (n = 29) and nonusers (n = 24) between the ages of 18 and 29 years participated in the dot-probe and eye-tracking picture-viewing tasks. The results showed that there was a significant difference in the variance of AB between the two groups. In the eye-tracking task, ENDS users displayed significantly greater net dwell time and fixation time at time frames of 6-9, 9-12, and 12-15 seconds, compared to nonusers. It is noteworthy that ENDS users exhibited attentional fluctuation toward ENDS cues as well as difficulties disengaging attention from ENDS cues. The current findings offer insight into the nature of attentional processes associated with ENDS cues and provide useful data to guide the development of a nurse-led cognitive intervention focusing on biased attentional processing related to ENDS cues.

Assessing the Dependence and Perceptions of the Harm and Addictiveness of Electronic Cigarettes among Saudi University Students: A Cross-Sectional Study

(1) Background: The rising prevalence of e-cigarette use among university students necessitates a comprehensive understanding of dependence levels and associated factors. This study investigates e-cigarette dependence among Jazan University students in Saudi Arabia. (2) Methods: With the use of a cross-sectional design, data were collected from 1187 students through an online survey from January to April 2024. Dependence levels were assessed using the Penn State Electronic Cigarette Dependence Index (PS-ECDI), and the Arabic version of the questionnaire was validated through pilot testing. Multivariable logistic regression analysis was employed to identify factors associated with e-cigarette dependence. (3) Results: The results indicated that among current e-cigarette users, 37.4% had low dependence, 34.4% had medium dependence, and 13.8% had high dependence. A significant proportion of current and ever users regarded e-cigarettes to be less harmful (50.6% and 44.4%, respectively) and less addictive (37.9% and 32.3%, respectively) than cigarettes. Significant factors influencing dependence included gender, with males showing higher odds of medium (AOR = 12.8, 95% CI: 3.4-47.6) and low dependence (AOR = 9.7, 95% CI: 2.5-37.3) compared to females. Longer duration of e-cigarette use (>2 years) was strongly associated with high dependence (AOR = 50, 95% CI: 7.7-324). Daily use and multiple quit attempts were also significant predictors of higher dependence levels. (4) Conclusions: These findings highlight the substantial e-cigarette dependence among university students and underscore the need for targeted interventions to address this growing public health concern.

Is Maintenance or Switching Between Freebase and Nicotine Salt Liquid Associated with Electronic Nicotine Delivery Systems Dependence?

BACKGROUND

Electronic nicotine delivery systems (ENDS) use one of two formulations of nicotine-freebase or nicotine salt. This study examines whether maintenance or switching between nicotine formulations is associated with ENDS dependence using longitudinal survey data.

METHODS

543 U.S. adults (21+) using ENDS frequently (5+ days/week) self-reported and uploaded photos of their most used ENDS liquids in wave 3-5 online surveys from September 2021 to April 2023. Nicotine formulation from photo data was used if available; otherwise, self-reported data were used. ENDS dependence was measured in each wave by a 4-item E-cigarette Dependence Scale (EDS: range 0-4, 4 being most dependent). Data were analyzed using ANCOVA.

RESULTS

Participants using nicotine salt liquids in three waves reported the highest EDS in wave 5 (49.3%, EDS = 2.59), followed by participants switching from salt to freebase (3.2%, EDS = 2.58), participants switching from freebase to salt (10.1%, EDS = 2.52), participants using freebase in three waves (34.9%, EDS = 2.18), and participants changing back and forth (2.4%, EDS = 2.11). After controlling for smoking status, participants stably using nicotine salt and participants switching from freebase to salt reported significantly higher EDS than those stably using freebase (p < 0.01).

CONCLUSIONS

Over an 18-month period, people consistently using nicotine salt liquids and participants switching from freebase to nicotine salt were more likely to have a higher ENDS dependence than those consistently using freebase liquids. Understanding how switching between nicotine formulations relates to ENDS dependence can inform nicotine formulation and concentration regulations that may impact addiction.

Reasons for continued usage of ENDS: Differences by device and liquid characteristics among US adults

INTRODUCTION

Motivations for using electronic nicotine delivery systems (ENDS) include quitting or reducing cigarette smoking, flavor, and addiction. This study examines whether the primary reason for continued ENDS usage changes over time, and its association with device and liquid characteristics.

METHODS

Data are from a longitudinal cohort study and include 526 US adults (≥21 years) using ENDS frequently (≥5 days/week) as self-reported, and uploaded photos of their most used ENDS devices and liquids and self-reported primary reason for continued ENDS usage in wave 2 (December 2020-April 2021) and wave 5 (February-April 2023). Device-liquid grouping was defined by device (disposable/disposable pod/refillable pod/tank, adjustable/no adjustable settings) and liquid (salt/freebase) characteristics. A device was classified as having adjustable settings if it allowed users to modify the power, coil, or airflow. Data were analyzed using multivariable logistic regressions and McNemar tests.

RESULTS

From wave 2 to 5, the primary reason for continued ENDS usage significantly changed, with more participants reporting addiction (29.2% vs 34.6%, p<0.001); and significantly more participants used disposable devices (salt, no adjustable settings) (7.9% vs 25.2%, p<0.001). Compared to those using tanks (freebase, adjustable settings), participants using devices with nicotine salt liquids were more likely to report addiction (AOR>2; 95% CI: 1.12-8.19); and participants using disposable devices (salt, no adjustable settings) were less likely to report quitting/reducing smoking as the primary ENDS use reason after controlling for smoking status and sociodemographic characteristics (AOR<0.6; 95% CI: 0.14-0.995).

CONCLUSIONS

Over a 2.5-year period, the proportion of participants continuing to use ENDS at least 5 days/week because of addiction grew, and participants' motivations varied by device-liquid grouping. Restrictions on nicotine salts may disproportionately impact those using ENDS because of addiction; and regulations targeting tanks with freebase liquids may disproportionately impact those using ENDS for smoking cessation/reduction.

Cigarettes, heated tobacco products and dual use: exhaled carbon monoxide, saliva cotinine and total tobacco consumed by Hong Kong tobacco users

BACKGROUND

Independent studies on exhaled carbon monoxide (CO) and saliva cotinine levels in regular heated tobacco product (HTP) users, and how they compare with conventional cigarette (CC) smokers, are lacking.

METHODS

A total of 3294 current users of CCs, HTPs or electronic cigarettes (ECs) from a household survey and a smoking hotspot survey were classified into seven groups: exclusive users of CCs, HTPs, ECs; dual users of CCs and HTPs, CCs and ECs, HTPs and ECs; and triple users. We measured exhaled CO level using the piCo Smokerlyzer (n=780) and saliva cotinine using NicAlert cotinine test strips (n=620). Among the seven groups, the differences in (1) CO and cotinine levels were examined using Kruskal-Wallis test, and (2) the average daily tobacco consumption in the past 30 days was examined using multivariable linear regression.

RESULTS

Both exclusive and dual users of CCs had a higher CO level than exclusive HTP or EC users (p<0.05). Exhaled CO levels were similar between HTP and EC users, as were saliva cotinine levels among the seven groups. Compared with exclusive CC users, those who also used HTPs or ECs smoked fewer CCs (CCs+HTPs: adjusted coefficient -2.79, 95% CI -3.90 to -1.69; CCs+ECs: -1.34, 95% CI -2.34 to -0.34), but consumed more tobacco sticks equivalent in total (2.79 (95% CI 1.61 to 3.96); 1.95 (95% CI 0.79 to 3.12)).

CONCLUSIONS

HTP or EC use showed lower exhaled CO but similar saliva cotinine levels compared with CC use. Dual users of CCs and HTPs/ECs smoked fewer CCs than exclusive CC users, but consumed more tobacco in total.

A Randomized Clinical Trial of a Quitline Vaping Cessation Intervention: Baseline Characteristics of Young Adult Exclusive E-Cigarette Users Seeking Treatment

Despite interest in quitting vaping among young adults (YAs), little is known about characteristics of e-cigarette (EC) users seeking treatment. In this study, YAs aged 18-24 living in the United States interested in vaping cessation treatment were recruited to complete an online survey regarding demographics and EC use. Primary eligibility criteria were EC use on at least 20 days per month (no other tobacco use), and interest in quitting in the next month. We report descriptive statistics for those who did and did not complete a mandatory coaching call (n = 981). In this sample, most EC users reported high nicotine dependence, a history of unsuccessful quit attempts (including 29.4% with previous NRT use), along with stress, anxiety, and depression. There were few meaningful differences in demographics, EC use behaviors, or behavioral health factors between those who engaged with a phone coaching call (fully enrolled in study; n = 508), and those who did not (n = 473). YAs demonstrated interest in vaping cessation support, but there were no clear characteristics for the half who did not complete a coaching call. Vaping cessation program designers should consider tailoring for the self-reported behavioral health concerns present in this population.

Evidence for sex differences in the impact of cytochrome P450 genotypes on early subjective effects of cannabis

Early positive subjective effects of cannabis predict the development of cannabis use disorder (CUD). Genetic factors, such as the presence of cytochrome P450 genetic variants that are associated with reduced Δ9-tetrahydrocannabinol (THC) metabolism, may contribute to individual differences in subjective effects of cannabis. Young adults (N = 54) with CUD or a non-CUD substance use disorder (control) provided a blood sample for DNA analysis and self-reported their early (i.e., effects upon initial uses) and past-year positive and negative subjective cannabis effects. Participants were classified as slow metabolizers if they had at least one CYP2C9 or CYP3A4 allele associated with reduced activity. Though the CUD group and control group did not differ in terms of metabolizer status, slow metabolizer status was more prevalent among females in the CUD group than females in the control group. Slow metabolizers reported greater past year negative THC effects compared to normal metabolizers; however, slow metabolizer status did not predict early subjective cannabis effects (positive or negative) or past year positive effects. Post-hoc analyses suggested males who were slow metabolizers reported more negative early subjective effects of cannabis than female slow metabolizers. Other sex-by-genotype interactions were not significant. These initial findings suggest that genetic variation in CYP2C9 and CYP3A4 may have sex-specific associations with cannabis-related outcomes. Slow metabolizer genes may serve as a risk factor for CUD for females independent of subjective effects. Male slow metabolizers may instead be particularly susceptible to the negative subjective effects of cannabis.

Exploring the opinions and potential impact of unflavoured e-liquid on smoking cessation among people who smoke and smoking relapse among people who previously smoked and now use e-cigarettes: findings from a UK-based mixed methods study

BACKGROUND

Although electronic cigarettes (e-cigarettes) appear to be effective in helping people who smoke to stop smoking, concerns about use of e-cigarettes among young people have led to restrictions on non-tobacco flavoured e-liquids in some countries and some US states. These restrictions could reduce the appeal of these products to non-smoking youth but could have negative consequences for people who smoke or use e-cigarettes.

METHODS

In this mixed methods study, we recruited UK adults who smoked or used to smoke and subsequently vaped to explore their opinions of unflavoured e-liquids and their beliefs about how they would be impacted by hypothetical e-liquid flavour restrictions. Participants trialled an unflavoured e-liquid instead of their usual nicotine product for four hours and completed a survey and an online interview.

RESULTS

Using Interpretive Phenomenological Analysis and graphically presented data, we found differences in participants' opinions of unflavoured e-liquid. If only unflavoured, tobacco flavoured, and menthol flavoured e-liquids remained on the UK market, some people who smoke or vape may be unaffected, but some may relapse to smoking or continue smoking. Despite most wanting to prevent young people from initiating vaping, participants had varying opinions on whether flavour restrictions would be an effective method.

CONCLUSIONS

The findings highlight that people who smoke and vape could be impacted by flavour restrictions in a range of ways, some of which could have a potential adverse impact on harm reduction efforts in the UK (e.g., by making smoking more appealing than vaping).

Development and initial validation of a new self-report measure to assess perceived dependence on tobacco and nicotine products

How nicotine is administered has evolved from cigarettes to various delivery systems. Assessing perceived dependence on nicotine-containing products now requires accounting for product specificity while allowing comparisons across products and users. This study aims to develop a new self-report measure to assess perceived dependence on tobacco and nicotine products (TNPs) among exclusive and poly-TNP users. A draft version of the new measure, the ABOUT-Dependence, was constructed based on literature review, qualitative research, and expert opinion. Data for scale formation and psychometric assessment was obtained through a US-based web survey (n = 2334) that included additional dependence measures for convergent validity assessment. Qualitative research confirmed a preliminary conceptual framework with seven sub-concepts. Following a cognitive debriefing, 19 items were considered to best represent the different sub-concepts. Psychometric findings supported a three-domain structure [i.e., behavioral impact (five items), signs and symptoms (five items), and extent/timing of use (two items)] and an overall total composite score. The data confirmed convergent and known-group validity, as well as test-retest reliability. The ABOUT-Dependence is a 12-item, psychometrically sound, self-report measure that may be used as a tool for research and further understanding of perceived dependence across the spectrum of TNP and TNP users.

Uncontrolled vaping and restraint strategies: A qualitative study

INTRODUCTION

Little is known about uncontrolled vaping, defined as vaping more than the user prefers. We sought to understand e-cigarette users' experiences with uncontrolled vaping and how they restrain their vaping.

METHODS

Participants were 24 US adult e-cigarette users recruited in 2021. We conducted semi-structured qualitative interviews about uncontrolled vaping and restraint strategies and analyzed findings based on behavioral categories described in the Process Model of Self-Control.

RESULTS

While most participants (21 of 24) described experiences of uncontrolled vaping, some expressed ambivalence about how much they vaped. To restrain vaping, willpower was rarely used and was not perceived as effective. Distraction, deployment of attention away from the urge to vape, and reappraisal, thinking differently about vaping such as reminding oneself of health consequences, were common and helped some participants limit use in the moment of wanting to vape. Participants described using both situation selection, choosing to be in situations where e-cigarette use was less possible, and situation modification, modifying their circumstances to restrict opportunities to vape.

DISCUSSION

Uncontrolled vaping is not yet a well-defined concept for many e-cigarette users. E-cigarette users employed proactive situational strategies that required planning ahead to restrain use and found these strategies more effective compared to reactive strategies. Tobacco control programs and interventions should consider leveraging restraint strategies that people who vape are naturally using and perceive to be effective.

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.

Evidence of premature vascular dysfunction in young adults who regularly use e-cigarettes and the impact of usage length

BACKGROUND

Electronic (e-) cigarettes are increasingly popular tobacco products on the US market. Traditional tobacco products are known to cause vascular dysfunction, one of the earliest indicators of cardiovascular disease (CVD) development. However, little is known about the effect of regular e-cigarette use on vascular function. The purpose of this study was to investigate the impact of regular e-cigarette use on vascular function and cardiovascular health in young, healthy adults.

METHODS

Twenty-one regular users of e-cigarettes (ECU) and twenty-one demographically matched non-users (NU) completed this study. Vascular health was assessed in the cutaneous microcirculation through different reactivity tests to evaluate overall functionality, endothelium-dependent vasodilation (EDD), and endothelium-independent vasodilation (EID). Macrovascular function was assessed using flow-mediated dilation (FMD).

RESULTS

Our results suggest that regular users of e-cigarettes present with premature microvascular impairment when compared to non-users. Specifically, they exhibit lower hyperemic (p = 0.003), thermal (p = 0.010), and EDD (p = 0.004) responses. No differences in EID between the groups were identified. We also identified that individuals who use e-cigarettes for longer than 3 years also present with systemic manifestations, as observed by significantly reduced macrovascular (p = 0.002) and microvascular (p ≤ 0.044) function.

CONCLUSIONS

Our novel data suggests that young, apparently healthy, regular users of e-cigarettes present with premature vascular dysfunction in the microcirculation when compared to non-users. We have also identified systemic vascular dysfunction affecting both the micro and macrovasculature in those young individuals who used e-cigarettes for longer than 3 years. Taken together, these findings associate regular e-cigarette use with premature vascular dysfunctions and adverse cardiovascular outcomes.

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.

An Evaluation of the Contextual Factors Associated With the Use of Either Tobacco or Electronic Cigarettes in Individuals Who Dual Use

INTRODUCTION

Little is known about patterns of dual use of tobacco and electronic cigarettes (e-cigarettes), especially regarding the factors that lead people to choose either product in particular situations. Identifying contextual factors that are associated with product use would enhance understanding of the maintenance of dual product use.

METHODS

Individuals who dual use (N = 102) completed ecological momentary assessment surveys via text message regarding the recent use of tobacco and e-cigarettes for 2 weeks. Product legality, availability, craving, the presence of other people who smoke/vape, and social disapproval were assessed. Data were analyzed using hierarchical logistic regression to identify factors associated with the likelihood of tobacco versus e-cigarette use.

RESULTS

Contexts associated with increased likelihood of using tobacco rather than e-cigarettes included being in the presence of other people who smoke (odds ratio [OR] = 3.50, p < .0001) and experiencing elevated tobacco cigarette craving (OR = 3.51, p < .0001). Decreased likelihood of tobacco over e-cigarette use was associated with smoking restrictions (OR = 0.26, p = .003), the presence of other people who vape (OR = 0.38, p < .001), and experiencing elevated e-cigarette craving (OR = 0.23, p < .0001). The legality of e-cigarettes, social disapproval, and the availability of the alternative product were not significantly associated with the use of one product over the other. An individual difference score of relative tobacco (vs. e-cigarette) use pattern did not significantly moderate these effects.

CONCLUSIONS

This study provided essential information regarding behavioral patterns of dual use, which informs our understanding of people who dual use. Contexts such as smoking restrictions, craving, and social context significantly differentiated between the use of tobacco and e-cigarettes. This suggests product-specific motivations for dual use of tobacco and e-cigarettes in people who use both.

IMPLICATIONS

This study assessed the relationship between momentary contextual factors and dual use in a nationally recruited sample of people who dual use. Assessments of dual use in daily life provided novel information regarding patterns of dual use as well as differential use-motivations for each product. This information will be essential to build a theoretical framework of dual use of tobacco and e-cigarettes.

Recruiting Latino young adults into a vaping cessation study via social media: Feasibility and cost analysis

INTRODUCTION

This study aims to assess the feasibility and cost of recruiting young Latino adults (aged 18-25 years) to participate in a vaping cessation study via social media and to describe the baseline characteristics of participants enrolled via social media.

METHODS

Paid advertisements were launched using the Meta Ads platform, which serves ads to users on Facebook and Instagram. Key measures of audience targeting included ages 18-25 years, all genders, and the following interests: 'electronic cigarettes', 'vape', 'Latin pop', and 'Latin music'. The advertisements invited young Latino adults to join a text messaging vaping cessation study. By clicking on the advertisements, interested individuals were directed to a website to fill in a contact form. The study team contacted individuals who filled in the form, assessed them for study eligibility, and, if eligible, enrolled them in the study.

RESULTS

A total of 164 individuals completed the contact form, and 26 were successfully enrolled in the study. The enrollment efficiency ratio was 15.9% (26/164). The cost per enrollment was US$94.14. The participants' mean age was 22.7 years (SD=1.6). Half of the participants (50%) were male, 38.5% were female, and 11.5% were gender non-conforming/non-binary. Two-thirds of the participants (69.2%) were born in the US, 23.1% in Puerto Rico, and 7.7% in Mexico. Eight participants (30.7%) selected Spanish as their language of preference. In terms of the type of vaping device, 16 participants (61.5%) indicated using disposables, 6 (23.1%) cartridges/pods, and 4 (15.4%) tanks/refillable. Sixteen participants (61.5%) reported using marijuana in e-cigarettes. Six participants (23.1%) had high e-cigarette dependence. Twenty participants (76.9%) had attempted to quit e-cigarettes in the past year.

CONCLUSIONS

It is feasible to recruit young Latino adults for a vaping cessation study via social media. Social media offers a relatively low-cost approach to recruiting a diverse sample of Latino young adults who vape.

Avoidance biases for vaping stimuli among college students with electronic-cigarette use

Previous research has suggested that individuals who smoke demonstrate a behavioral tendency to approach rather than avoid smoking-related stimuli (i.e., approach bias). This study assessed whether 149 undergraduates with varying levels of e-cigarette use demonstrated an approach bias for vaping-related stimuli on an Approach-Avoidance Task (AAT). In contrast to our hypotheses, participants with e-cigarette use demonstrated a significant avoidance bias to vaping-related stimuli, and this effect appeared to be primarily driven by female e-cigarette users. Further, we found that more severe e-cigarette use was associated with numerous adverse outcomes, including reduced quality of life and increased vaping cravings, depressive symptoms, perceived stress, and cannabis use severity. Overall, our findings elucidate various negative impacts of e-cigarette use and suggest a potential role for sex differences in approach-avoidance tendencies toward vaping-related stimuli among young adults.

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.

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.

Effects of liquid nicotine concentration and flavour on the acceptability of electronic nicotine delivery systems (ENDS) among people who smoke participating in a randomised controlled trial to reduce cigarette consumption

BACKGROUND

Research is needed to understand the acceptability of electronic nicotine delivery systems (ENDS) as a smoking reduction aid. This study examines the acceptability of ENDS by liquid nicotine concentration and flavour among people who smoke using ENDS to reduce their smoking.

METHODS

People who smoke cigarettes but were naïve to ENDS participated in a double-blind randomised controlled trial to reduce conventional cigarette smoking. Participants were randomised to either a control cigarette substitute (CS) or one of three ENDS groups; 0 mg/mL, 8 mg/mL or 36 mg/mL nicotine concentration. ENDS flavour was chosen by the participant (tobacco or menthol). Participants reported their CS, ENDS and cigarettes per day (CPD) from the past 7 days at 1-month, 3-month and 6-month follow-up visits. Participants also reported side effects and measures of satisfaction, psychological reward, aversion and craving relief. Outcome variables were modelled using linear mixed effects by the following groups: liquid nicotine concentration, flavour and a flavour-nicotine concentration interaction.

RESULTS

Participants (n=520) were 41.2% male, 67.3% white, had a mean age of 46.2 years and smoked a mean of 18.6 CPD (SD=7.74) at baseline. All flavour and concentration groups decreased CPD from baseline to all follow-up visits with the 36 mg/mL experiencing the greatest reduction, compared with the 0 mg/mL and 8 mg/mL groups. All groups except the 36 mg/mL group decreased their product use over time. The use of menthol flavour was associated with fewer side effects at 3 months (p=0.02) and lesser aversion at 1 month (p=0.03) compared with tobacco-flavoured ENDS. The 36 mg/mL group experienced the greatest craving relief and greatest aversion compared with other groups.

CONCLUSIONS

Both nicotine concentration and flavour appear to have independent, as well as interactive, effects that influence ENDS acceptability among people who use cigarettes.

Expanding on cross-price elasticity: Understanding tobacco product demand and substitution from the cross-price purchase task

We examine whether cigarettes serve as substitutes for electronic nicotine delivery systems (ENDS) among ENDS users and demonstrate methodological extensions of data from a cross-price purchase task to inform policies and interventions. During a clinical laboratory study, n = 19 exclusive ENDS users and n = 17 dual cigarette/ENDS users completed a cross-price purchase task with cigarettes available at a fixed price while prices of own-brand ENDS increased. We estimated cross-price elasticity using linear models to examine substitutability. We defined five additional outcomes: nonzero cross-price intensity (purchasing cigarettes if ENDS were free), constant null demand (not purchasing cigarettes at any ENDS price), cross-product crossover point (first price where participants purchased more cigarettes than ENDS), dual-demand score (percentage of prices where both products were purchased), and dual-use break point (minimum relative price to force complete substitution). The cross-price elasticity results indicated that cigarettes could serve as substitutes for ENDS among ENDS users on average, but this average effect masked substantial heterogeneity in profiles of demand (here, a measure of the drug's reinforcement potential). Policies and regulations that increase ENDS prices appear unlikely to steer most exclusive ENDS users toward cigarette use, as most would not purchase cigarettes at any ENDS price, but they could prompt some dual users to substitute cigarettes completely while others remain dual users. This heterogeneity in consumer responses suggests additional indices of cross-product demand are useful to characterize the anticipated and unanticipated effects of tobacco price policies more fully.

Comparison of brain nicotine accumulation from traditional combustible cigarettes and electronic cigarettes with different formulations

Rapid brain accumulation is critical for the acute reinforcing effects of nicotine. Although nicotine formulation (free-base vs. protonated or salt) in electronic cigarette (E-cig) liquid affects user satisfaction, its impact on brain nicotine accumulation (BNA) from E-cig use has not been evaluated in comparison with traditional combustible cigarettes (C-cigs) using a within-subjects design. BNA was directly assessed with 29 adult dual users (13 females) of E-cigs and C-cigs, using [11C]nicotine and positron emission tomography (PET). Participants underwent two 15-min upper body (from chest to head) scanning sessions during which they inhaled a single puff of [11C]nicotine-labeled vapor from E-cigs with free-base nicotine or C-cig smoke in a randomized order. Seventeen of them also went through another session during which they inhaled from E-cigs with nicotine salt. A full-body scan was also conducted at each session to measure total absorbed dose of [11C]nicotine. Mean maximum nicotine concentration (Cmax) in brain following inhalation of free-base nicotine E-cig vapor was 19% and 15% lower relative to C-cig smoke and nicotine salt E-cig vapor (ps = 0.014 and 0.043, respectively). The Cmax values did not differ significantly between the C-cig and nicotine salt E-cig. Mean values of time to the maximum concentration (Tmax) were not significantly different between the two types of E-cig, but they were 64% and 40% longer than that for C-cig smoking (ps = 0.0005 and 0.004, respectively). Mean Cmax with C-cigs and free-base nicotine E-cigs were greater in females relative to males and correlated with T1/2 of lung nicotine clearance and participants' pack-years. These results suggest that while E-cigs with free-base nicotine formulation can deliver nicotine rapidly to the brain, those with nicotine salt formulation are capable of even more efficient brain nicotine delivery closely resembling combustible cigarettes. Therefore, nicotine formulation or pH in E-liquid should be considered in evaluation of E-cigs in terms of abuse liability and potential in substituting for combustible cigarettes.

Exploring the prevalence, knowledge, attitudes and influencing factors of e-cigarette use among university students in Palestine: a cross-sectional study

OBJECTIVES

E-cigarettes have gained popularity, especially among young adults. This study aims to determine the prevalence of e-cigarette smoking, assess knowledge and attitudes and identify associated factors among Palestinian university students.

DESIGN

A cross-sectional study.

SETTING AND PARTICIPANTS

The study was conducted among Palestinian university students in early 2023.A self-administered questionnaire was used to survey 1792 students from six Palestine universities in the West Bank. The questionnaire covered various aspects, including sociodemographic information, daily habits, exposure to smoking, attitudes and knowledge about e-cigarettes. Data were analysed using descriptive statistics, χ2 tests and multivariate regression analysis.

RESULTS

The study revealed a high prevalence of tobacco use (41.2%), with e-cigarette use prevalent among 19.7% of participants. Knowledge about e-cigarettes was suboptimal, with misconceptions regarding their safety and health effects. Negative attitudes towards e-cigarettes were common, and students with negative attitudes were more likely to use e-cigarettes (aOR=2.6, 95% CI: 1.9 to 3.6). Gender (aOR=2.1, 95% CI: 1.4 to 3.0), waterpipe smoking (aOR=4.5, 95% CI: 3.2 to 6.3), physical inactivity (aOR=1.4, 95% CI: 1.1 to 1.9), high coffee consumption (aOR=1.6, 95% CI: 1.1 to 2.3), spending time with friends (aOR=2.4, 95% CI: 1.5 to 3.7), having a mother who is a smoker (aOR=1.5, 95% CI: 1.1 to 2.2) and having a friend who uses e-cigarettes (aOR=1.5, 95% CI: 1.1 to 2.1) were significantly associated with e-cigarettes use.

CONCLUSIONS

E-cigarette use is a growing concern among Palestinian university students. Combating this trend should include educational initiatives, social interventions and policy measures to promote informed decision-making and discourage e-cigarette use. Comprehensive tobacco control programs considering various tobacco and nicotine products and involving multiple stakeholders are warranted.

A Comparison of Mental Health Symptoms among Adults Who Vape Nicotine, Cannabis, or Both

OBJECTIVES

Dual use of combustible cannabis and nicotine is related to worse mental health symptoms (MHS); however, little is known about MHS among those who vape cannabis and nicotine. The current study aimed to determine if dual use of cannabis and nicotine vapes is associated with worse MHS compared to single use and to identify correlates of MHS for dual users.

METHODS

We used Amazon Mechanical Turk to survey adults (N = 492) who used nicotine or cannabis vapes in the past 30 days on stress, anxiety, depression, vape use behaviors and sociodemographic information. We conducted hierarchical linear regressions to compare MHS between dual vs. single substance vape use and to identify correlates of MHS, including sociodemographic variables and vape use characteristics.

RESULTS

The final sample was 37.6% female, 87.6% White, and 11% Hispanic/Latinx with a mean age of 34.15 years. After controlling for sociodemographic characteristics and combustible product use, dual users had significantly higher mean MHS severity than single users. For dual users, younger age and being married were associated with higher symptoms of depression and stress. Holding a medical cannabis card was associated with higher anxiety symptoms.

CONCLUSION

The findings suggest that dual use of cannabis and nicotine vapes is associated with worse MHS severity compared to single substance use.

Indirect Effects of Body Mass Index and Sweet Taste Responsiveness on E-Cigarette Dependence: The Role of E-Cigarette Motives

Background: Recent research has shown obesity to be associated with e-cigarette use and appeal, but models have yet to examine how weight status may be related to e-cigarette dependence among e-cigarette users. Objectives: To increase our understanding of pathways from body mass index (BMI) to e-cigarette dependence, the present cross-sectional observational study investigated a model in which BMI, sweet taste responsiveness, and the interaction of BMI and sweet taste responsiveness are associated with e-cigarette dependence indirectly via seven conceptually-distinct motives for e-cigarette use. Data from several e-cigarette clinical laboratory research studies were pooled and analyzed; only current e-cigarette users were included in the analyses (N=330). Structural equation modeling was used to analyze the hypothesized model. Results: BMI was positively associated with lower social/environmental goad motives and higher weight control motives, and BMI x sweet taste interaction terms found that sweet taste responsiveness strengthened the association of BMI and weight control motives. BMI was not directly or indirectly associated with e-cigarette dependence nor was there a bivariate association between BMI and e-cigarette dependence. Sweet taste responsiveness was positively associated with greater affiliative attachment motives, cognitive enhancement motives, cue exposure-associative process motives, weight control motives, and affect enhancement motives. Sweet taste responsiveness was bivariately associated with e-cigarette dependence and mediation paths show indirect relations to e-cigarette dependence via three of the seven motives. Conclusions: The findings suggest that sweet taste responsiveness, opposed to BMI, is associated with a wider range of e-cigarette use motives and indirectly relates to e-cigarette dependence via several e-cigarette use motives.

Emotion Dysregulation and E-Cigarette Expectancies among College Student E-Cigarette Users

Background: E-cigarette outcome expectancies (i.e., beliefs about the expected consequences of e-cigarette use) are a key factor in motivating use. Emotion regulation difficulties have demonstrated significant associations with outcome expectancies; however, there has yet to be an examination of associations between specific emotion regulation difficulties and specific e-cigarette outcome expectancies, which could serve as targets for intervention efforts. Therefore, the current study sought to examine the unique predictive ability of specific emotion regulation difficulties in terms of e-cigarette outcome expectancies. Methods: Participants were 116 college student e-cigarette users (Mage = 19.72, SD = 1.88; 71.6% female) who completed self-report questionnaires for course credit. Results: Greater difficulties engaging in goal-directed behavior when experiencing negative emotions and fewer difficulties accessing effective emotion regulation strategies were associated with positive reinforcement outcome expectancies. Greater emotion regulation difficulties in general were also associated with negative reinforcement outcome expectancies, though there were no significant individual predictors. Conclusion: These results suggest that greater emotion regulation difficulties are associated with mood-related e-cigarette outcome expectancies, and targeting emotion regulation difficulties, particularly difficulty engaging in goal-directed behavior when upset, may be useful to incorporate into intervention efforts.

Pain interference among adult dual combustible and electronic tobacco users in terms of perceived barriers for quitting

Electronic cigarette (e-cigarette) use has become increasingly common among combustible cigarette users, and dual use may represent a more severe type of nicotine addiction. Experiencing pain is one prevalent domain that may be important to understand quit processes and behavior among dual users. Although most past research on pain and nicotine/tobacco has focused on combustible cigarette use, initial work on e-cigarette users has found that greater pain severity is associated with higher levels of dependence and negative thinking patterns about e-cigarette use. Yet, there has been no effort to explore the experience of pain among dual users in terms of perceived barriers for quitting combustibles or e-cigarettes. The present study sought to examine pain interference among dual combustible and e-cigarette users in terms of perceived barriers for quitting among 138 (45.9% female; Mage = 35.96 years, SD = 7.16) adult dual users (i.e., users of both combustible cigarette and e-cigarettes). Hierarchical linear regression models indicated that pain interference was significantly associated with both perceived barriers for cessation of combustible cigarettes and perceived barriers for cessation of e-cigarettes. Overall, the present investigation served as an initial evaluation of the role of pain interference in terms of perceived barriers for quitting combustible and e-cigarettes among adult daily dual users. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Dual Electronic and Combustible Cigarette Use: Understanding the Relation of Cannabis Use with E-Cigarette Outcomes

Background: E-cigarette use is on the rise and many who use e-cigarettes also smoke combustible cigarettes. Dual use (i.e., use of both electronic and combustible cigarettes) is associated with greater rates of cannabis use and cannabis use among individuals who engage in dual use is related to more severe ecigarette-related problems. Yet, no known studies have tested whether cannabis use is related to more severe e-cigarette problems via negative affect and the expectation that e-cigarettes can help manage negative affect. Objectives: The current study tested this hypothesis among 400 adults who endorsed dual use, 33% of whom endorsed current (past three month) cannabis use. Results: Results indicated that participants with cannabis use reported more anxiety, depression, e-cigarette problems, and the following e-cigarette use expectancies: negative consequences, negative reinforcement, and weight concerns. Multiple mediator models found that the relation between cannabis use status and e-cigarette problem severity was mediated by anxiety (but not depression) and by negative reinforcement and weight concerns (but not negative consequences) expectancies. Serial mediator models indicated that the relation between cannabis use and e-cigarette problems occurred via the serial effects of anxiety and negative reinforcement (but not weight concerns) expectancies. Conclusions: These results highlight several clinical correlates of cannabis use among adults who smoke combustible and e-cigarettes, and suggest that anxiety and the expectation that e-cigarettes may help manage such negative emotions play important roles in e-cigarette-related problems among these individuals.

Adult smokers' Complete Switching Away from Cigarettes at 6, 9, and 12 Months after Initially Purchasing a JUUL e-Cigarette

Background: Electronic nicotine delivery systems (ENDS) have the potential to benefit public health if smokers completely switch from cigarettes to ENDS. Methods: A cohort of adult smokers (age ≥ 21) who purchased a JUUL Starter Kit was followed for 12 months after the initial purchase. We defined "switching" as past-30-day abstinence from smoking (even if JUUL use had stopped), and analyzed factors associated with achievement and maintenance of self-reported repeated point-prevalence switching (RPPS) at three follow-ups, i.e., no past-30-day smoking at months 6, 9, and 12. Results: RPPS was reported by 21.6% of the 12,537 evaluable smokers. Smokers with lighter smoking history and lower cigarette dependence at baseline were more likely to report RPPS. RPPS was also associated with daily use of JUUL (Month-3: OR = 2.32, 95% CI = 2.02-2.68; Month-6: OR = 1.73, 95% CI = 1.42-2.10), and with greater subjective reinforcing effects from JUUL use (assessed by the mCEQ, Month-3: OR = 1.46, 95% CI = 1.38-1.56; Month-6: OR = 1.11; 95% CI = 1.02-1.20). Even among smokers who did not meet the criteria of RPPS (i.e., who smoked at least once), 35.5% reported past 30-day point-prevalence switching on at least one follow-up, and their cigarette consumption was substantially reduced compared to baseline. Conclusions: Approximately one-fifth of adult smokers reported 30-day point-prevalence abstinence at 6, 9, and 12 months after purchasing JUUL. Greater use of JUUL and stronger subjective reinforcing effects were associated with nonsmoking, validating the potential for ENDS to substitute for smoking, with potential for positive impacts on individual and population health.

Vaping and smoking cue reactivity in young adult electronic cigarette users who have never smoked combustible cigarettes: A functional neuroimaging study

Introduction

The rapid growth in the use of electronic cigarettes (e-cigarettes) among young adults who have never smoked combustible cigarettes is concerning, as it raises the potential for chronic vaping and nicotine addiction. A key characteristic of drug addiction is the elevated neural response to conditioned drug-related cues (i.e., cue reactivity). Generalized reactivity to both vaping and smoking cues may signify an increased risk for smoking initiation in non- smoking vapers. In this study, we used functional magnetic resonance imaging (fMRI) to evaluate brain responses to vaping and smoking cues in young adult never-smoking vapers.

Methods

Sixty-six young adult never-smoking vapers underwent functional MRI while viewing visual cues pertaining to vaping, smoking, and nicotine-unrelated unconditioned reward (i.e., food). A priori region-of-interest analysis combined with exploratory whole-brain analysis was performed to characterize neural reactivity to vaping and smoking cues in comparison to food cues.

Results

The medial prefrontal cortex and the posterior cingulate cortex, regions that play a key role in drug cue reactivity, showed significantly increased neural response to vaping cues compared to food cues. The posterior cingulate cortex additionally showed increased neural responses to smoking cues compared to food cues.

Conclusions

Despite never having smoked combustible cigarettes, young adult vapers exhibited heightened neural susceptibility to both vaping and smoking cues within brain systems associated with cue reactivity. The findings shed light on the mechanisms underlying nicotine addiction and smoking initiation risk in this critical population and may contribute to the development of science-based interventions and regulatory measures in the future.

IMPLICATIONS

The escalating vaping prevalence among US never-smoking young adults is alarming, due to its potential ramifications for nicotine addiction development. Nicotine addiction is characterized by elevated neural response to conditioned nicotine-related cues. Using functional neuroimaging, we showed that young adult non-smoking vapers exhibited heightened neural susceptibility to both vaping and smoking cues within brain systems previously associated with cue reactivity. Such cross-reactivity to both types of nicotine cues may serve as the mechanism underlying nicotine addiction and smoking initiation risk in this population. Our findings may contribute to the development of science-based interventions and regulatory measures addressing the vaping epidemic.

Milestones in the natural course of the onset of e-cigarette dependence among adolescents and young adults: Retrospective study

INTRODUCTION

There is considerable controversy about the development of dependence among e-cigarette users. This study describes the average amount of time using e-cigarettes before dependence milestones emerge and the differences in developing dependence between e-cigarette users who smoke cigarettes compared to those who do not.

METHODS

Adolescents and young adults aged 16-25 living in Canada were recruited into an online survey in 2021. Current (past-month) e-cigarette users completed 15 items assessing dependence from the Penn-State Electronic Cigarette Dependence Index and the E-cigarette Dependence Scale for a total of 12 behavioural (e.g., difficulty refraining from vaping) and 3 frequency (e.g., using e-cigarette daily, weekly, or monthly) indicators of dependence milestones. Number of years after e-cigarette onset at which the cumulative probability of attaining each milestone was 25 % was computed.

RESULTS

Among 1205 participants, most (80.6 %) were female, 73.7 % were Caucasian, and 49.7 % resided in Ontario. Ten of the 12 e-cigarette use milestones were attained by 25 % of respondents 2 years after starting vaping except for daily cigarette use (2.5 years after onset) and waking at night to vape (5.6 years after onset). Within the entire study population, frequency milestones (weekly, monthly, daily e-cigarette use) were attained faster by ever-smokers (hazard ratio compared to attainment by never-smokers: 1.12, 1.21, and 1.28 respectively), whereas for at least monthly users, behavioural milestones were attained faster by never-smokers.

DISCUSSION

Many current e-cigarette users developed symptoms of e-cigarette dependence between two and five years since onset. Never smokers may be at higher risk of becoming e-cigarette dependent since they attained e-cigarette dependence milestones faster than smokers.

Comparison of exhaled carbon monoxide levels and its association with nicotine dependence between electronic and tobacco cigarettes: A cross-sectional study among teenage smokers

Carbon monoxide (CO), resulting from incomplete combustion such as tobacco smoking, serves as an indicator of nicotine addiction. The aim of this study was to compare the levels of exhaled CO levels between electronic cigarette (e-cigarette) and tobacco smokers and to determine the association between nicotine dependence and exhaled CO levels in e-cigarette and tobacco smokers. A cross-sectional study was conducted using purposive sampling on active smokers, with 70 smokers in each group. The nicotine dependence was measured using the Penn State Nicotine Dependence Index (PSNDI) questionnaire for the e-cigarette group and the Fagerstrom questionnaire for the tobacco smoking group. The CO level was measured using the smokerlyzer piCO. To compare the mean exhaled CO levels between e-cigarettes and tobacco smoker groups, the Mann-Whitney test was used. The Mann-Whitney test and Kruskal-Wallis test were used to assess the associations between nicotine dependence and mean exhaled CO levels in the e-cigarette smoker group and in the tobacco smoker group, respectively. The majority of e-cigarette smokers were 17 years old (65.7%) and male (75.7%). Among tobacco smokers, the majority were also 17 years old (44.3%), and mostly male (91.4%). The mean exhaled CO levels in the tobacco smoker group were significantly higher than the e-cigarette smoker group, 6.86 ppm vs 1.61 ppm with p<0.001. There was a significant association between nicotine dependence and exhaled CO levels among tobacco smokers (p<0.001). Nicotine dependence was not associated with exhaled CO levels among e-cigarette smokers. This study highlights that the smokerlyzer piCO devise could be used to screen nicotine addiction in tobacco smokers.

Development and Validation of LC-MS/MS Method for Determination of Cytisine in Human Serum and Saliva

Cytisine (CYT) is a quinolizidine alkaloid used for nicotine addiction treatment. Recent clinical trial data regarding cytisine confirm its high effectiveness and safety as a smoking cessation treatment. CYT's popularity is growing due to its increased availability and licensing in more countries worldwide. This increased use by smokers has also resulted in an urgent need for continued drug research, including developing appropriate analytical methods for analyzing the drug in biological samples. In this study, a simple, fast, and reliable method combining hydrophilic interaction liquid chromatography and electrospray ionization quadrupole time of flight mass spectrometry (HILIC/ESI-QTOF-MS) for the determination of CYT in human serum and saliva was developed and validated. This was undertaken after the previous pre-treatment of the sample using solid-phase extraction (SPE). A hydrophilic interaction liquid chromatography (HILIC) column with a silica stationary phase was used for chromatographic analysis. In a linear gradient, the mobile phase consisted of acetonitrile (ACN) and formate buffer at pH 4.0. The proposed method was fully validated and demonstrated its sensitivity, selectivity, precision, and accuracy. The method was successfully applied to determine CYT in serum and, for the first time, in saliva. The findings indicate that saliva could be a promising non-invasive alternative to measure the free concentration of CYT.

Human abuse liability assessment of e-cigarettes: Why, what and how?

Cigarette smoking is the world's leading cause of preventable death and disease. Alternative nicotine products such as e-cigarettes have tobacco harm reduction potential, by providing smokers with an alternative form of nicotine delivery but with either the reduced presence or absence of the numerous harmful chemicals found in combustible cigarette smoke. One aspect of importance in determining the potential of e-cigarettes to provide a viable alternative to combustible cigarettes for smokers is their ability to cause dependence, also known as their abuse liability. E-cigarettes with little or no abuse liability would be unlikely to be used as a substitute for cigarettes, whereas at least some degree of abuse liability is acknowledged as supportive both to aiding cigarette substitution or complete cessation and to preventing relapse. Given this link between abuse liability and substitution efficacy, human studies assessing the abuse liability of e-cigarettes are important to determine their true harm reduction potential. In this review, the concept of tobacco product abuse liability is discussed, along with the primary elements-pharmacokinetics and pharmacodynamics (subjective effects)-that need to be assessed to determine abuse liability. The review also presents a number of human abuse liability study design considerations and discusses what existing studies in the literature tell us about the abuse liability and harm reduction potential of e-cigarettes.

Effect of unguided e-cigarette provision on uptake, use, and smoking cessation among adults who smoke in the USA: a naturalistic, randomised, controlled clinical trial

Background

As summarised in the most recent Cochrane review, the few clinical trials on e-cigarettes are largely focused on smoking cessation. We aimed to determine the naturalistic uptake, use, and impact of e-cigarettes among adults who may or may not want to stop smoking.

Methods

In this naturalistic, randomised, controlled clinical trial, adult smokers, across the motivational spectrum and with minimal history of e-cigarette use, were recruited online from the general community within 11 cities across the USA. Participants were randomly assigned (2:1) to either receive either a free 4-week supply of flavoured, tank-style e-cigarette, or not. E-cigarette group participants received a battery and device with up to 30 pre-filled tanks, offered among five flavours, with minimal instructions on use. The study's primary purpose was to descriptively assess naturalistic uptake and usage of the e-cigarette, and to secondarily assess its impact on smoking behavior. The latter, assessed through six months of follow-up, included: a) self-reported 7-day point prevalence abstinence, b) incidence of quit attempts, and c) smoking reduction. This trial is registered at ClinicalTrials.gov, NCT03453385.

Findings

Between 5/2018 and 3/2022, 638 adult smokers were enrolled and randomly assigned (427 in the e-cigarette group and 211 in the no-product control group). Uptake of e-cigarettes was robust: approximately 70% of participants used the product, with average usage exceeding 4 days per week during the initial 30 days. Based on an intent-to-treat approach where missing data is imputed as smoking, almost all behavioral outcomes favored the e-cigarette group relative to no-product control, including point prevalence abstinence at six months (Odds Ratio [OR] = 1.8; 95% Confidence Interval [CI] = 1.0-3.1), cumulative incidence of 24-hr quit attempts (OR = 1.5; 95% CI = 1.0-2.2), and having reduced smoking by at least 50% since baseline (OR = 1.8; 95% CI = 1.2-2.7). Results were similar under an alternative imputation.

Interpretation

Complementing cessation-focused trials, results suggest that unguided e-cigarette use also leads to smoking cessation, allaying the notion that causal effects of e-cigarettes on cessation are not reflective of real-world scenario of self-determined use. For smokers who may not be able to quit using existing pharmacologic approaches, e-cigarettes may be considered to achive that purpose.

Funding

National Cancer Institute.

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.

Nicotine Intake in Adult Pod E-cigarette Users: Impact of User and Device Characteristics

INTRODUCTION

This study examined user behavior, e-cigarette dependence, and device characteristics on nicotine intake among users of pod-mod e-cigarettes.

AIMS AND METHODS

In 2019-2020, people who use pod-mods in the San Francisco Bay Area completed questionnaires and provided a urine sample for analysis of total nicotine equivalents (TNE). The relationship between TNE and e-cigarette use, e-cigarette brands, e-liquid nicotine strength, e-cigarette dependence, and urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), as a measure of combustible cigarette exposure, were examined.

RESULTS

Of 100 participants (64% male, 71% in the 18-34 age group, 45% white), 53 used JUUL primarily, 12 used Puff Bar primarily, and 35 used other brands, including Suorin; 48 participants reported current cigarette smoking. Participants most often reported use of e-liquid with 4.5%-6.0% nicotine (68%), fruit (35%), tobacco (28%), and menthol or mint flavors (26%), used e-cigarettes on 25.5 (SD = 6.3) days a month, 10.2 (SD = 14.2) times a day, and 40% used 1-2 pods/cartridges per week. In bivariate analysis, urinary TNE was higher with greater frequency (days used) and intensity (number of pods used) of e-cigarette use, e-cigarette dependence, and combustible cigarette use. In multivariable analysis, days of e-cigarette use in the last 30 days, number of pods used per week, and NNAL levels were significantly associated with TNE. There was no significant impact of e-liquid nicotine strength on TNE.

CONCLUSIONS

Nicotine intake among people who used pod-mod e-cigarettes increased with e-cigarette consumption and e-cigarette dependence, but not with e-liquid nicotine strength. Our findings may inform whether FDA adopts a nicotine standard for e-cigarettes.

IMPLICATIONS

The study examined how device and user characteristics influence nicotine intake among pod-mod e-cigarette users. Nicotine intake increased with frequency (days of e-cigarette use in past 30 days) intensity of use (number of pods used per day) and e-cigarette dependence but not with the flavor or nicotine concentration of the e-liquids. Regulation of nicotine concentration of e-liquids is unlikely to influence nicotine exposure among adult experienced pod-mod users.

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.

Understanding perceived addiction to and addictiveness of electronic cigarettes among electronic cigarette users: a cross-sectional analysis of the International Tobacco Control Smoking and Vaping (ITC 4CV) England Survey

BACKGROUND AND AIMS

The addictive potential of electronic cigarettes (e-cigarettes) remains to be fully understood. We identified patterns and correlates of perceived addiction to e-cigarettes and perceived addictiveness of e-cigarettes relative to tobacco cigarettes (relative addictiveness) in dual users as well as exclusive e-cigarette users.

DESIGN, SETTING AND PARTICIPANTS

Observational study using cross-sectional survey data from England (2016) from the International Tobacco Control Project (ITC) Four Country Smoking and Vaping (4CV) survey. The study comprised 832 current e-cigarette users who had been vaping for at least 4 months.

MEASUREMENTS

Perceived addiction to e-cigarettes and relative addictiveness of e-cigarettes were examined. Socio-demographic factors were age, gender and education; markers of addiction included urge to vape, time to first vape after waking and nicotine strength used; vaping and smoking characteristics included frequency and duration of e-cigarette use, intention to quit, adjustable power or temperature, enjoyment, satisfaction relative to tobacco cigarettes and tobacco cigarette smoking status.

FINDINGS

A total of 17% of participants reported feeling very addicted to e-cigarettes, while 40% considered e-cigarettes equally/more addictive than tobacco cigarettes. Those who felt very addicted had higher odds of regarding e-cigarettes as more addictive than tobacco cigarettes (odds ratio 3.4, 95% confidence interval 2.3-5.1). All markers of addiction, daily use and enjoyment were associated with higher perceived addiction, whereas time to first vape after waking, daily vaping and perceiving vaping as less satisfying than smoking were associated with relative addictiveness.

CONCLUSIONS

Markers of addiction to e-cigarettes appear to correspond with perceived addiction to e-cigarettes, suggesting that self-reported perceived addiction might serve as an indicator of addiction. Prevalence both of markers of addiction and perceived addiction were comparatively low overall, suggesting a limited but relevant addictive potential of e-cigarettes. Additionally, positive and negative reinforcement, reflected here by enjoyment and relative satisfaction, might play a role in e-cigarette addiction.