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Rationale Electronic nicotine delivery systems and heated tobacco products are noncombustible alternatives for adult smokers. Evidence suggests sufficient nicotine delivery and satisfying effects are necessary to facilitate switching away from smoking; nicotine delivery varies across electronic nicotine delivery systems within limited nicotine concentrations. Objectives To assess the nicotine delivery and subjective effects of prototype JUUL2 System in two nicotine concentrations, currently-marketed US JUUL System (“JUUL”), IQOS-brand heated tobacco product, and combustible cigarettes. Methods Adult smokers (N = 40) completed a 5-arm cross-over product-use laboratory confinement study. Nicotine pharmacokinetics and subjective effects were assessed following use of: (1) JUUL2 prototype 18 mg/mL nicotine; (2) JUUL2 prototype 40 mg/mL; (3) JUUL 59 mg/mL; (4) IQOS 18 mg/g; and (5) usual brand combustible cigarette, each evaluated during ad libitum (10 min) and controlled (5 min, 10 standardized puffs) use. Results Nicotine delivery was greatest for combustible cigarettes, followed by JUUL2 prototype 40 mg/mL, IQOS, JUUL2 prototype 18 mg/mL, and JUUL 59 mg/mL. Nicotine delivery from JUUL2 prototype 18 mg/mL was significantly greater than JUUL 59 mg/mL after ad libitum use. JUUL products were significantly more satisfying and effective at reducing craving than IQOS. JUUL2 prototype 40 mg/mL was significantly more aversive than other JUUL products. Conclusions Prototype JUUL2 and JUUL 59 mg/mL products were rated higher than IQOS on subjective measures associated with switching away from smoking. The JUUL2 prototype 40 mg/mL produced aversive responses and would require modifications to be a viable product for adult smokers. Nicotine delivery and subjective responses to JUUL2 prototype 18 mg/mL suggest a product based on this prototype may facilitate increased switching among adult smokers.

INTRODUCTION: Youth use of electronic nicotine delivery systems (ENDS) is a continuing concern, making it important to assess evolving patterns, especially as non-tobacco, non-menthol (NTM) flavors were withdrawn for pod-based (but not disposable) ENDS in February 2020. METHODS: Trends in past-30-day (P30D) ENDS use and smoking prevalence, usual device type, flavor (tobacco, mint/menthol, or fruit/sweet/other), and regular/last-used brand in PATH Waves 4 (2017), 4.5 (2018), 5 (2019), and 5.5 (2020) were examined. Shifts between 2019-2020 in flavor use for pods and disposables were examined. Wave 5.5 is uninformative regarding brand use because common disposable brands were not queried. RESULTS: P30D ENDS use peaked in 2019 at 8.6% of all youth, subsequently declining by nearly half to 4.5% in 2020. Meanwhile, P30D cigarette smoking declined to an all-time low (1.3%) in 2020. Within this overall decline, consumption shifted to disposable ENDS, which increased nearly 10-fold (from 5.0% to 49.2% of P30D ENDS users). Relatedly, use of fruit/sweet/other flavors remained similar overall between 2019 and 2020 (approximately 75%-80% of P30D ENDS users), but the use of these flavors became concentrated in disposable ENDS in 2020 (a 12-fold increase from 4.4% to 58.4% of fruit/sweet/other-flavor users). CONCLUSIONS: PATH results show similar trends to other US national surveys in youth ENDS trends. The removal of non-tobacco, non-menthol flavors in pod-based ENDS (while remaining available in disposables) has likely driven youth towards disposable devices, resulting in continued high use of fruit/sweet/other flavors, which are now predominant in users of disposable ENDS.

Background: Evidence indicates that electronic nicotine delivery systems (ENDS) pose lower risk than cigarettes; however, many smokers misperceive ENDS to be equally ormore harmful, possibly deterring them from switching. This study examines whether relative risk perceptions of JUUL vs. smoking are associated with subsequent switching, among smokers who recently initiated JUUL use. Methods: N=16,996 current established smokers who recently purchased a JUUL Starter Kit were followed 6 times over 12 months. Relative risk perceptions were assessed using both direct and indirect measures (i.e., contrasting JUUL and smoking directly in questions, and deriving from separate absolute scales). Repeated-measures logistic regression examined switching across follow-up (no smoking in past 30 days) as a function of baseline risk perceptions, adjusting for demographics and baseline smoking behavior. Results: Perceiving JUUL as less harmful than smoking was associated with higher switching rates, using both direct (e.g., odds ratio [OR]=1.48 for “JUUL much less” vs. “more/much more harmful”) and indirect (OR=1.07, for each 10-unit increase in ratio; OR=1.51 for highest (6-100) vs. lowest (0 to ppConclusions: Smokers who perceive JUUL as less harmful than cigarettes have higher odds of switching. Future research should examine whether messaging which aligns relative risk perceptions with current evidence can facilitate switching, especially among heavier smokers.

Introduction: More real-world evidence on exposure to harmful and potentially harmful constituents (HPHCs) and on biological effects when cigarette smokers switch to e-cigarettes would be useful. 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 e-cigarettes exclusively for ≥ 6 months (Switchers). Assessments included biomarkers of exposure (BOEs) to select HPHCs, biomarkers of potential harm (BOPHs) related to smoking-related diseases, and psychometric assessments of tobacco dependence and respiratory symptoms. Planned analyses compared geometric means, adjusted for covariates; exploratory analyses adjusted for additional covariates. Results: Nicotine was higher in Switchers, who were 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 e.g., white blood cell count, MCP1, HbA1c) were significantly lower in Switchers than Smokers; HDL was significantly higher. Switchers reported significantly lower tobacco dependence and respiratory symptoms 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 less respiratory symptoms.

Background: The prevalence of electronic cigarette (“e-cigarettes”) use among youth has raised alarm over recent years. Vaping is usually assumed to be of nicotine, but uncertainties in survey definitions may also include non-nicotine substances which can impose different risks (particularly marijuana). The current study quantifies the proportions of nicotine-specific and marijuana-specific vaping among adolescents. Methods: Data from the Monitoring the Future (MTF) 2020 survey and National Youth Tobacco Survey (NYTS) 2021 were analyzed with respect to the substance vaped: nicotine, marijuana, or (in MTF) flavoring only. Past-30-day nicotine-specific vaping (exclusively, or also having vaped other substances) and marijuana-specific vaping were calculated. Results were also broken down by grade level, by cigarette smoking history (current, former, or never), and among frequent e-cigarette users (on 20 days out of the past 30 days). Results: Among past-30-day e-cigarette users, 14.6% (MTF) and 18.8% (NYTS) reported not vaping _any_ nicotine in the past 30 days. Marijuana use was reported by 45.7% (MTF) and 42.5% (NYTS) of past-30-day vapers. Both _nicotine_ vaping and marijuana vaping in the past 30 days were more common in current and former smokers than in never-smokers, and in frequent vapers (of any substance). Conversely, never-smokers were more commonly _exclusively_ vaping marijuana compared to current and former smokers. Conclusions: A notable proportion of self-reported past-30-day e-cigarette users reported not vaping nicotine, and nearly half of self-reported past-30-day e-cigarette users vaped marijuana. Inclusion of more detailed data capturing the variety of substances used in vaping devices is imperative for accurate public health surveillance of both nicotine and marijuana vaping among US adolescents, considering their different respective harms and regulatory mechanisms.

Background: Alcohol consumption promotes lapses to smoking among smokers trying to quit, perhaps particularly among smokers with lower dependence. We assessed how the role of alcohol in lapses varies over time. Methods: This is a secondary analysis of ecological momentary assessment data collected from 159 daily smokers (mean age=43.90 (SD=10.41), 56.60% female) who drink alcohol. During the 4 weeks following initial cessation (quit >24 hours), a logistic time-varying effect model (TVEM) modeled momentary assessments of lapses and temptations to smoke compared to randomly-selected moments as a function of concurrently-assessed recent alcohol use (past 15 minutes). Time was examined continuously. Results: Recent alcohol use was associated with smoking lapses, particularly for less nicotine dependent individuals, and the association varied across time. For individuals who did not smoke within 5 minutes of waking, alcohol use became a significant predictor of lapse on Day 1 post-quit, increased in strength until Day 7, then decreased such that alcohol use was no longer associated with lapse by Day 25. For this subgroup, the associations between alcohol use and temptations were relatively stable and significant from Day 1 to 22 post-quit. Results were similar when dependence was assessed by the Nicotine Dependence Symptom Scale. Conclusions: The association between drinking and smoking lapse and temptations varies over time, peaking early in smoking abstinence and declining thereafter. This could reflect progressive relapse of most vulnerable individuals or habituation to alcohol as a smoking cue. Interventions to prevent alcohol-related lapses are essential early in the quit period.

BACKGROUND Smokers often experience respiratory symptoms (eg, morning cough), and those who stop smoking, including those who do so by switching completely to electronic nicotine delivery systems (ENDS), may experience reductions in symptoms. Existing respiratory symptom questionnaires may not be suitable for studying these changes, as they are intended for patient populations, such as those with chronic obstructive pulmonary disease (COPD). OBJECTIVE This study aimed to develop a respiratory symptom questionnaire appropriate for current smokers and for assessing changes when smokers stop smoking. METHODS The Respiratory Symptom Experience Scale (RSES) was derived from existing instruments and subject matter expert input and refined through cognitive debriefing interviews (n=49). Next, for purposes of the quantitative psychometric evaluation, the RSES was administered to smokers (n=202), former smokers (no tobacco use in >6 months; n=200), and switchers (n=208, smokers who switched to ENDS for >6 months), all of whom had smoked for at least 10 years (mean age 33 years). Participants, who averaged 62 (SD 12) years of age, included 28% (173/610) with respiratory allergy symptoms and 17% (104/610) with COPD. Test-retest reliability was assessed by repeat assessment after 1 week in 128 participants. RESULTS A generalized partial credit model confirmed that the response options were ordered, and a parallel analysis using principal components confirmed that the scale was unidimensional. With allowance for 2 sets of correlated errors between pairs of items, a 1-factor graded response model fit the data. Discrimination parameters were approximately 1 or greater for all items. Scale reliability was 0.80 or higher across a broad range of severity (standardized scores −0.40 to 3.00). Test-retest reliability (absolute intraclass correlation) was good, at 0.89. RSES convergent validity was supported by substantial differences (Cohen d=0.74) between those with and without a diagnosis of respiratory disease (averaging 0.57 points, indicating that differences of this size or smaller represent meaningful differences). RSES scores also strongly differentiated those with and without COPD (d=1.52). Smokers’ RSES scores were significantly higher than former smokers’ scores (PPP=.34). CONCLUSIONS The RSES fills an important gap in the existing toolkit of respiratory symptom questionnaires; it is a reliable and valid tool to assess respiratory symptoms in adult current and former smokers, including those who have switched to noncombusted nicotine products. This suggests that the scale is sensitive to respiratory symptoms that develop in smokers and to their remission when smokers quit or switch to noncombusted nicotine products intended to reduce the harm of smoking. The findings also suggest that switching from cigarettes to ENDS may improve respiratory health.

BackgroundStudies have suggested that some US adult smokers are switching away from smoking to e-cigarette use. Nationally representative data may reflect such changes in smoking by assessing trends in cigarette and e-cigarette prevalence. The objective of this study is to assess whether and how much smoking prevalence differs from expectations since the introduction of e-cigarettes.MethodsAnnual estimates of smoking and e-cigarette use in US adults varying in age, race/ethnicity, and sex were derived from the National Health Interview Survey. Regression models were fitted to smoking prevalence trends before e-cigarettes became widely available (1999–2009) and trends were extrapolated to 2019 (counterfactual model). Smoking prevalence discrepancies, defined as the difference between projected and actual smoking prevalence from 2010 to 2019, were calculated, to evaluate whether actual smoking prevalence differed from those expected from counterfactual projections. The correlation between smoking discrepancies and e-cigarette use prevalence was investigated.ResultsActual overall smoking prevalence from 2010 to 2019 was significantly lower than counterfactual predictions. The discrepancy was significantly larger as e-cigarette use prevalence increased. In subgroup analyses, discrepancies in smoking prevalence were more pronounced for cohorts with greater e-cigarette use prevalence, namely adults ages 18–34, adult males, and non-Hispanic White adults.ConclusionPopulation-level data suggest that smoking prevalence has dropped faster than expected, in ways correlated with increased e-cigarette use. This population movement has potential public health implications.

Purpose To examine the association between intensive, longitudinal ecological momentary assessment (EMA) and self-reported eating behaviors. Methods Secondary analysis of the EMPOWER study—a 12-month observational study that examined the microprocesses of relapse following intentional weight loss using smartphone-administered EMA—was conducted. Participants were asked to complete four types of EMA surveys using a mobile app. For this analysis, only the number of completed random EMA surveys was used. Using linear mixed-effects modeling, we analyzed whether the number of completed random EMA surveys was associated with changes in self-reported dietary restraint, dietary disinhibition, and susceptibility to hunger measured using the Three-Factor Eating Questionnaire (TFEQ). Results During the 12-month study, 132 participants completed a mean of 1062 random EMA surveys (range: 673–1362). The median time it took for participants to complete random EMA surveys was 20 s and 90% of random EMA surveys were completed within 46 s. The number of completed random EMA surveys was not significantly associated with the TFEQ scores. Conclusions Intensive longitudinal EMA did not influence self-reported eating behaviors. The findings suggest that EMA can be used to frequently assess real-world eating behaviors with minimal concern about assessment reactivity. Nonetheless, care must be taken when designing EMA surveys—particularly when using self-reported outcome measures. Level of evidence Level III, prospective observational study.

ObjectivesTo measure adherence over six months of progestin-only pill (POP) use.Study DesignProspective observational cohort study measuring adherence to daily dosing and timing of dose in patients prescribed a POP, with up to six months of follow-up, conducted from January to October 2020. A pharmacy benefit manager identified potential participants with a newly prescribed POP and extended an invitation to participate. We enrolled qualified respondents by telephone, trained them to use an electronic diary to report daily whether they had taken their POP and at what time. We followed participants for up to six months. We calculated adherence to daily pill taking as the proportion of evaluable days in which a participant took a POP, and the proportion of participants reporting ≥85% adherence. We calculated adherence to same time each day as the proportion of doses taken no later than three hours after the previous dose time of day.ResultsThe user population comprised 199 participants, 154 (77.4%) of whom completed six months of follow-up. The majority (n = 170, 85.4%) were taking norethindrone. Norethindrone users reported POP intake on 22,327 (96.4%) of 23,156 evaluable days, with 155 (91.2%) participants reporting ≥85% adherence; less than half (n = 73, 42.9%) reported 100% adherence. Participants reported adherence to same time each day on 21,698 of 22,157 (97.9%) evaluable days.ConclusionsAmong participants taking a prescribed POP, participants demonstrated high adherence for daily pill taking and the same time of day, though the majority were not 100% adherent.ImplicationsThis study reports data specific to adherence among those taking a progestin-only pill (POP) in the prescription setting. Clinicians who counsel patients about POP use should be aware that majority of patients were not 100% adherent, although most report ≥85% adherence.

IntroductionEvidence suggests that cigarette smokers who switch to electronic nicotine delivery systems (ENDS) reduce their exposure to harmful toxicants and carcinogens. It is unclear if dual-use is associated with decreases in exposure to toxicants.MethodsThis parallel-group confinement study assessed changes in biomarkers of exposure (BOEs) over six days among healthy adult smokers who were randomized into 1 of 11 study groups: eight JUUL-brand System (JUUL) groups (4 JUUL flavors [Virginia Tobacco, Menthol, Mint, Mango] × 2 nicotine concentrations [5.0% or 3.0% by weight]); Dual-Use group used preferred JUUL flavor (5.0% nicotine) and ≤50% usual brand (UB) cigarettes/day; UB Cigarette group and one group abstained from all tobacco/nicotine product use (Abstinence group). Urine and blood analysis assessed changes in primary BOE endpoints (NNAL, 3-HPMA, MHBMA, S-PMA COHb) and secondary BOE endpoints (NNN, HMPMA, CEMA, 1-OHP, O-toluidine, 2-NA, 4-ABP) among 279 adult smokers.ResultsIn JUUL groups, median percent reductions in primary BOEs (Day 6–Baseline) were 90%–≥100% of Abstinence; there were no significant differences between JUUL groups and Abstinence. All reductions in JUUL groups were substantially and statistically significantly greater than reductions in the UB Cigarette group (ps < 0.025). Median reductions in primary BOEs in the Dual-Use group were 43%–55% of Abstinence. Similar results were observed for secondary BOEs.ConclusionThis study suggests that the use of JUUL as a complete or partial substitute (i.e., dual-use with ≥50% reduction in cigarette consumption) for combustible cigarettes can substantially reduce exposure to multiple toxins associated with cigarette smoking.ImplicationsThis study adds to the growing body of evidence supporting the utility of ENDS products as potentially reduced-harm alternatives to cigarettes for adult smokers. Adult smokers who switched completely from cigarette smoking to use of the JUUL System (“JUUL”) in two nicotine concentrations (5.0% and 3.0%) and four flavors significantly reduced their exposure to multiple classes of cigarette-related toxicants. Additionally, smokers who used JUUL and continued smoking but reduced their daily cigarette consumption by ≥50% (dual users) also significantly reduced their toxicant exposure compared to cigarette smoking.

Introduction Electronic nicotine delivery systems (ENDS) may improve public health if they facilitate smokers switching away from cigarettes. Conceptually, switching is facilitated when ENDS provide adequate nicotine delivery. Switching rates among smokers who purchased the JUUL System (“JUUL”) were compared in the United Kingdom (UK), where regulations limit nicotine concentration to 20 mg/mL versus North America (N.Am.; United States and Canada), where higher concentrations are available. Aims and Methods Adult established smokers (age ≥21, smoked ≥100 cigarettes, smoking some days or every day at baseline) who newly purchased JUUL were recruited into a longitudinal study (UK: N = 1247; N.Am.: N = 8835). Complete switching (no smoking for ≥30 days) was assessed 1, 3, and 6 months after purchase; propensity score matching (PSM) and logistic regression compared switching after adjusting for baseline characteristics. Results In both N.Am. and UK, ≥82% of participants reported using the highest JUUL nicotine concentration available (UK: 18 mg/mL; N.Am.: 59 mg/mL). Unadjusted switching rates did not differ at 1 month (17%–18%); unadjusted and adjusted rates were significantly higher in N.Am. (vs. UK) at 3 and 6 months. In the PSM sample, after additional covariate adjustment, rates were significantly higher in N.Am. (vs. UK) at 3 months (31.5% vs. 22.7%; odds ratio [95% confidence interval, CI] = 1.59 [1.25, 2.02]) and 6 months (38.0% vs. 26.0%; odds ratio [95% CI] = 1.79 [1.37, 2.35]). Conclusions These results suggest availability of ENDS in nicotine concentrations greater than 20 mg/mL may be associated with increased switching among adult smokers. Differences in smoking and ENDS use characteristics did not explain associations of location and switching; however, between-country differences may be affected by unmeasured factors. Implications Switching rates were lower among smokers who purchased the JUUL System (“JUUL”) in the UK, where regulations limit nicotine concentration to 20 mg/mL versus N.Am. (United States and Canada), where higher concentrations are available—before and after controlling for differences in smoking and ENDS use characteristics. These results suggest availability of ENDS in nicotine concentrations greater than 20 mg/mL may be associated with increased switching among adult smokers. Between-country differences may be affected by unmeasured factors; future research should consider these factors and the extent to which regulatory policy environments may explain differences in switching among adult smokers.

Objectives: Those underage should not use tobacco products, including electronic nicotine delivery systems. A technologically-based solution developed by Juul Labs Inc to restrict underage access seeks to automate transactions, structurally mandate age-verification, and limit the quantity of JUUL products purchased per transaction. A pilot of this standards-based approach, referred to as RACS™ (Retail Access Control Standards), was conducted to assess efficacy. Methods: RACS was implemented at 171 stores within 3 retail chains selling tobacco products in 3 states. "Secret shopper" compliance audits, in which a mystery shopper attempted to purchase JUUL products, were conducted at participating stores before and after implementation of RACS, to test compliance with age-verification and product-quantity limits. Audit failure rates were compared pre- and post-RACS implementation to assess effectiveness. Comparisons were made overall, by chain, state, and failure type. Results: A total of 3990 audits were conducted. We found large, statistically significant reductions (p < .001) in failure rates for age-verification and compliance with product-quantity limits after implementing RACS, as compared to pre-RACS rates, declining to near zero. Conclusions: Utilizing enhanced access controls can be part of a comprehensive, evidence-based tobacco-control strategy to address underage use of all tobacco products, including JUUL.

Objectives: We assessed adult never smokers' trajectories of smoking over 12 months after a first-time JUUL Starter Kit (JSK) purchase. Methods: Adult (≥ 21) never smokers (N = 3853) who purchased a JSK were recruited into an observational naturalistic study. Analyses distinguished those who had previously used ENDS (NS+E, N = 2848) from those who had not (NS-NE, N = 1005). Participants were invited to complete follow-up assessments at 1, 2, 3, 6, 9, and 12 months. "Smoking" was defined as any past-30-day smoking ("even a puff"). Results: Past-30-day smoking was reported by 5.01% of NS+E at month one, and 7.56% at month 12; for NS-NE, these were 10.23% and 12.35%. In both groups, < 5% reported smoking at both 9 and 12 months. Across follow-ups, 25%-49% of those reporting having smoked then said they were now smoking "not at all"; the remainder reported low frequency (10-12 days-per-month) and quantity (2-4 cigarettes-per-day) of smoking. Past-30-day use of JUUL remained at ≥ 80% across follow-ups. Each additional day-per-month of JUUL use decreased the odds of smoking by 1%. Conclusions: Some adult never smokers who purchased a JSK reported smoking during the suceeding year; smoking was light and intermittent. Participants who used JUUL more frequently were less likely to smoke.

Objectives: The Adult JUUL System User Switching and Smoking Trajectories (ADJUSST) study assessed the smoking and JUUL use trajectories of adults who purchased JUUL. In this paper, we describe study methods, characterize the sample, and assesses potential for bias due to loss to follow-up. Methods: We entered 55,414 US adults (≥ age 21) who purchased a JUUL Starter Kit for the first time (online or at retail) in 2018 into a naturalistic, longitudinal observational study, irrespective of baseline smoking status. Participants were invited for follow-ups 1, 2, 3, 6, 9, and 12 months later, focused on assessing past-30-day smoking and JUUL use. Analyses assessed potential bias due to non-response. Results: Over 90% of participants had a history of smoking; 62.8% were past-30-day smokers; 23.3% were former smokers. Participants' average age was 30; 75% were white. Most participants (77.6%) completed some follow-ups; 25% completed all follow-ups. Baseline differences among complete responders (N = 13,729), partial responders (N = 29,252), and complete non-responders (N = 12,433) were small. When recontacted, few 12-month non-responders said their non-response was due to smoking; many reported no past-30-day smoking. Conclusions: The study may elucidate smoking trajectories of adult JUUL users. The potential for bias due to loss to follow-up in ADJUSST was limited.

Objectives: In this study, we assessed changes in dependence as smokers transitioned from cigarette smoking to exclusive use of the JUUL System ("JUUL"), contrasting users of 5.0% versus 3.0% nicotine concentration pods. Methods: Overall, 5246 adult (age ≥ 21) established smokers (> 100 cigarettes lifetime) who purchased a JUUL device completed online surveys at baseline, when smoking, and one and 3 months later; 1758 reported no past-30-day smoking ('switching') at one or both timepoints. Analyses compared dependence on cigarettes (at baseline) and JUUL (at follow-up), as assessed by the 4-item PROMIS scale (Range: 0-4). Results: Switching increased from Month 1 (18.3%) to Month 3 (28.6%); switchers at one month (Difference = 0.23) and 3 months (0.24) showed lower mean baseline cigarette dependence. Dependence decreased significantly (ps < .001) from baseline cigarette dependence to JUUL dependence at both one (from 1.82 to 1.59) and 3 months (1.97 to 1.73); changes did not significantly differ between users of 5.0% and 3.0% (ps > .43). Dependence on JUUL did not change significantly from Month 1 to Month 3. Conclusions: Dependence decreased as smokers transitioned from smoking to exclusive use of JUUL, similarly for users of both nicotine concentrations. Smokers who switch to JUUL may reduce their nicotine dependence.

This special issue addresses key topics relating to the public health impact of the use of electronic nicotine delivery devices (ENDS), particularly JUUL-brand ENDS. Smokers smoke for nicotine, but are harmed by the byproducts of combustion. ENDS can play a role in tobacco harm reduction offering a noncombustible alternative source of nicotine for adult smokers who would otherwise continue smoking. Papers presented here estimate the prevalence of ENDS and JUUL use among young and older adults, and document the 12-month smoking trajectories of adults who purchased a JUUL Starter Kit. Overall, smoking prevalence was halved, with most smokers switching completely as dual use declined. This held for subpopulations defined by demographics and psychiatric comorbidity. For those who did not switch, most significantly reduced (50%+) their cigarette consumption. Another study reports that dependence declines as smokers switch from smoking to using JUUL. The public health potential of ENDS is undermined by use of ENDS by nonsmokers, especially underage individuals. Some smoking was reported by adult former and never smokers, with little evidence of persistent smoking, and lower risk of smoking among those using JUUL more frequently. Regarding underage use, one paper reports that technology can ensure age-verification at point of sale. Population modeling integrating impacts on diverse populations indicates that availability of ENDS is expected to avert millions of premature deaths in the US. We believe these papers make a substantial contribution to the field of tobacco science and smoking control.

Objectives: In this study, we prospectively assessed changes in smoking a year after US adults' first-time purchase of a JUUL Starter Kit (JSK). Methods: Descriptive analyses assessed transitions in smoking status at 12 months among adult (age ≥21) JSK purchasers providing baseline and 12-month follow-up data (N = 27,164 [49.0% of baseline]), stratified by baseline smoking status. Baseline regular use of other ENDS was also considered. Results: Purchasers included baseline past 30-day smokers (65.2%), former smokers (12.0%), and never smokers (9.7%); over 90% were ever-smokers. One year later, the majority (58%) of those smoking at baseline reported no longer smoking. Former smokers or never smokers who were smoking at 12 months represented less than 2% of respondents. Former and current smokers who were regularly using other ENDS at baseline were less likely to report smoking at 12 months. Conclusions: Past 30-day smoking prevalence in a large longitudinal study of first-time JSK purchasers fell by more than half over 12 months. Analyzing the sample composition at purchase and transitions within subgroups defined by smoking status allows for a detailed understanding to help inform assessments of the population health impact of ENDS.

Objectives: Many smokers who start using ENDS engage in dual use of cigarettes and ENDS. This paper examines time trends in dual use after a JUUL Starter Kit purchase, and changes in cigarette consumption among those remaining dual users. Methods: In the ADJUSST study, a cohort of adult smokers who purchased a JUUL Starter Kit were followed naturalistically 6 times over 12 months. Trends in dual use and reported complete switching away from cigarettes (ie, no past 30-day smoking), and changes in daily average cigarettes per day from baseline at 6 and 12 months were examined. Results: Dual use declined over time as complete switching increased. By 12 months, 43.2% reported dual using, and 51.2% reported switching away from cigarettes. Among dual users, approximately 60% reduced their cigarette consumption substantially (by ≥ 50%); average reductions in cigarette consumption were > 80%. Only a small minority (3%-10%) substantially increased cigarette consumption. Conclusions: Dual use of smoking and JUUL declines over time as switching away from smoking increases. This suggests that, for most smokers, dual use is a transitional state leading to switching completely away from cigarettes. Furthermore, dual use is often marked by substantial reductions in cigarette consumption.

Objectives: In this study, we assessed complete switching away from cigarette smoking among adult smokers who purchased a JUUL Starter Kit (JSK). Methods: Adult (age ≥ 21) established smokers (smoked ≥ 100 lifetime cigarettes) who purchased a JSK in 2018 were invited to complete online surveys 1, 2, 3, 6, 9 and 12 months after initial JSK purchase. Point prevalence of switching (no past 30-day smoking) was assessed at each follow-up. Repeated measures logistic regression models evaluated associations of sociodemographic factors, baseline smoking characteristics and time-varying JUUL System ("JUUL") use characteristics and switching across the 12-month period. Results: Respondents (N = 17,986) were 55.0% male, 78.3% white, mean age = 32.65 years (SD = 10.81), mean baseline cigarettes/day = 11.10 (SD = 8.16). The proportion self-reporting switching increased over time: one-month (27.2%[3718/13,650]), 2-month (36.4%[4926/13,533]), 3-month (41.0%[5434/13,257]), 6-month (46.6%[5411/11,621]), 9-month (49.4%[6017/12,186]), and 12-month (51.2%[6106/11,919]); 33.1% reported switching at both 9-month and 12-month follow-ups. In prospective analyses, smokers with lower cigarette dependence, shorter smoking history, lower cigarette consumption, more frequent JUUL use, greater satisfaction from initial JUUL use, and higher JUUL dependence were significantly more likely to switch. Conclusions: Rates of switching with JUUL increased over time. Over 50% of respondents reported complete switching away from cigarettes 12 months following purchase. Greater use of and dependence on JUUL predicted switching.

Ecological momentary assessment (EMA) studies investigate intensive repeated observations of the current behavior and experiences of subjects in real time. In particular, such studies aim to minimize recall bias and maximize ecological validity, thereby strengthening the investigation and inference of microprocesses that influence behavior in real-world contexts by gathering intensive information on the temporal patterning of behavior of study subjects. Throughout this paper, we focus on the data analysis of an EMA study that examined behavior of intermittent smokers (ITS). Specifically, we sought to explore the pattern of clustered smoking behavior of ITS, or smoking ‘bouts’, as well as the covariates that predict such smoking behavior. To do this, in this paper we introduce a framework for characterizing the temporal behavior of ITS via the functions of event gap time to distinguish the smoking bouts. We used the time-varying coefficient models for the cumulative log gap time and to characterize the temporal patterns of smoking behavior, while simultaneously adjusting for behavioral covariates, and incorporated the inverse probability weighting into the models to accommodate missing data. Simulation studies showed that irrespective of whether missing by design or missing at random, the model was able to reliably determine prespecified time-varying functional forms of a given covariate coefficient, provided the the within-subject level was small.

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 examined 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 baseline smoking history and lower baseline cigarette dependence were more likely to report RPPS. RPPS was also associated with patterns of and responses to JUUL use: Daily use of JUUL at month 3 (OR=2.25; 95% CI=1.96–2.60) and month 6 (OR=1.81; 95% CI=1.48–2.22) was associated with higher rates of RPPS, and as were greater subjective reinforcing effects from JUUL use (assessed by the mCEQ, month-3: OR=1.70, 95% CI=1.57–1.83; month-6: OR=1.15; 95% CI=1.06–1.25). 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 non-smoking, validating the potential for ENDS to substitute for smoking, with potential for positive impacts on individual and population health.

Little is known about relapse among non-daily, intermittent smokers (ITS), who have difficulty quitting, despite a lack of dependence. To analyze situations associated with temptations to smoke and smoking lapses among ITS trying to maintain abstinence. Participants were 130 initially abstinent ITS in the placebo arm of a smoking cessation study. EMA data captured participants’ situations and states in temptations (n = 976), including those that eventuated in lapses (n = 147), for up to 6 weeks. Randomly timed assessments assessed background states (n = 11,446). Participants also reported coping performed to prevent lapses. Multilevel analyses compared temptations to background situations, and lapse episodes to resolved temptations. Temptations were marked by exposure to smoking cues, including others smoking, lax smoking restrictions, and alcohol consumption, as well as more negative affect. Lapses did not differ from resolved temptations in craving intensity, but were more often associated with smoking cues and availability of cigarettes, alcohol consumption, and worse affect, and were more often attributed to good moods. Both behavioral and cognitive coping responses were associated with avoiding lapsing, but behavioral coping had much larger effects. The effects of affective distress on lapse risk were mediated by its effects on coping. Smoking cues play a major role in ITS’ temptations and lapses, perhaps indicating a degree of behavioral dependence. Affective distress also played a role in ITS lapses, undermining the idea that the affective distress seen in daily smokers’ lapses is due to nicotine withdrawal. The data reinforce the important role of coping in preventing lapses.

RATIONALE: Electronic nicotine delivery systems (ENDS) and heated tobacco products (HTP) are noncombustible alternatives for adult smokers. Evidence suggests sufficient nicotine delivery is necessary to facilitate switching away from smoking; nicotine delivery varies across ENDS within limited nicotine concentrations. OBJECTIVES: To assess the nicotine delivery and subjective effects of currently-marketed US JUUL System (“JUUL”) ENDS, prototype JUUL2 ENDS in two nicotine concentrations, IQOS HTP and combustible cigarettes. METHODS: Adult smokers (N=40) completed a 5-arm cross-over product-use laboratory confinement study. Nicotine PK and subjective effects were assessed following use of: (1) JUUL 59mg/mL nicotine; (2) JUUL2 Prototype 18mg/mL; (3) JUUL2 Prototype 40mg/mL; (4) IQOS HTP 18mg/g; (5) usual brand (UB) cigarette, each evaluated during _ad libitum_ (10 minutes) and controlled (5 minutes, 10 standardized puffs) use. RESULTS: Nicotine delivery was greatest for UB cigarette, followed by JUUL2 Prototype 40mg/mL, IQOS, JUUL2 Prototype 18mg/mL, and JUUL 59mg/mL. Nicotine delivery from JUUL2 Prototype 18mg/mL was significantly greater than JUUL 59 mg/mL after _ad libitum_ use. JUUL products were significantly more satisfying and effective at reducing craving than IQOS. JUUL2 Prototype 40mg/mL was significantly more aversive than other JUUL products. CONCLUSIONS: Currently-marketed JUUL 59mg/mL and prototype JUUL ENDS products were rated higher than IQOS on subjective measures associated with switching away from smoking. The JUUL2 Prototype 40mg/mL produced aversive responses, and requires modifications to be a viable product for adult smokers. Nicotine delivery and subjective responses to JUUL2 Prototype 18mg/mL suggest a product based on this prototype may facilitate increased switching among adult smokers.

Electronic nicotine delivery systems and heated tobacco products are noncombustible alternatives for adult smokers. Evidence suggests sufficient nicotine delivery and satisfying effects are necessary to facilitate switching away from smoking; nicotine delivery varies across electronic nicotine delivery systems within limited nicotine concentrations.To assess the nicotine delivery and subjective effects of prototype JUUL2 System in two nicotine concentrations, currently-marketed US JUUL System ("JUUL"), IQOS-brand heated tobacco product, and combustible cigarettes.Adult smokers (N = 40) completed a 5-arm cross-over product-use laboratory confinement study. Nicotine pharmacokinetics and subjective effects were assessed following use of: (1) JUUL2 prototype 18 mg/mL nicotine; (2) JUUL2 prototype 40 mg/mL; (3) JUUL 59 mg/mL; (4) IQOS 18 mg/g; and (5) usual brand combustible cigarette, each evaluated during ad libitum (10 min) and controlled (5 min, 10 standardized puffs) use.Nicotine delivery was greatest for combustible cigarettes, followed by JUUL2 prototype 40 mg/mL, IQOS, JUUL2 prototype 18 mg/mL, and JUUL 59 mg/mL. Nicotine delivery from JUUL2 prototype 18 mg/mL was significantly greater than JUUL 59 mg/mL after ad libitum use. JUUL products were significantly more satisfying and effective at reducing craving than IQOS. JUUL2 prototype 40 mg/mL was significantly more aversive than other JUUL products.Prototype JUUL2 and JUUL 59 mg/mL products were rated higher than IQOS on subjective measures associated with switching away from smoking. The JUUL2 prototype 40 mg/mL produced aversive responses and would require modifications to be a viable product for adult smokers. Nicotine delivery and subjective responses to JUUL2 prototype 18 mg/mL suggest a product based on this prototype may facilitate increased switching among adult smokers.

BACKGROUND: Self-efficacy, or the perceived capability to engage in a behavior, has been shown to play an important role in adhering to weight loss treatment. Given that adherence is extremely important for successful weight loss outcomes and that sleep and self-efficacy are modifiable factors in this relationship, we examined the association between sleep and self-efficacy for adhering to the daily plan. Investigators examined whether various dimensions of sleep were associated with self-efficacy for adhering to the daily recommended lifestyle plan among participants (N=150) in a 12-month weight loss study. METHODS: This study was a secondary analysis of data from a 12-month prospective observational study that included a standard behavioral weight loss intervention. Daily assessments at the beginning of day (BOD) of self-efficacy and the previous night’s sleep were collected in real-time using ecological momentary assessment. RESULTS: The analysis included 44,613 BOD assessments. On average, participants reported sleeping for 6.93±1.28 hours, reported 1.56±3.54 awakenings, and gave low ratings for trouble sleeping (3.11±2.58;0: no trouble; 10: a lot of trouble) and mid-high ratings for sleep quality (6.45±2.09;0: poor; 10: excellent). Participants woke up feeling tired 41.7% of the time. Using linear mixed effects modeling, a better rating in each sleep dimension was associated with higher self-efficacy the following day (all p values

Background The US Food and Drug Administration is considering reductions in the nicotine content of cigarettes to reduce smoking and tobacco dependence. A randomized study showed that even non-daily, intermittent smokers (ITS) reduced their cigarette consumption when switched to very-low-nicotine-content cigarettes (VLNCCs). This paper assesses whether switching ITS to VLNCCs results in decreased dependence and whether subsequent cigarette consumption is mediated by decreased dependence. Methods ITS randomized to VLNCCs (n = 118) or normal nicotine content cigarettes (n = 120) completed multiple measures of dependence (Fagerstrom Test of Nicotine Dependence [FTND], Nicotine Dependence Syndrome Scale [NDSS], Wisconsin Inventory of Smoking Dependence Motives [WISDM], and Hooked on Nicotine Checklist [HONC]) at Baseline and 2, 6, and 10 weeks after randomization. A principal component factor score captured common variance among these measures (except FTND). Cigarettes per day (CPD) was assessed by three convergent methods. Results Switching ITS to VLNCCs reduced dependence on all measures except the WISDM Secondary Dependence Motives and HONC. Except for the effects on the factor score, these effects of VLNCCs could be accounted for by contemporaneous CPD. Week-2 dependence measures did not prospectively predict weeks 3–4 CPD, once antecedent dependence and CPD were accounted for. "Cheating" among participants who appear to have smoked conventional cigarettes did not affect the findings. Discussion Among ITS, switching to VLNCCs results in reduced tobacco dependence. However, the reductions in dependence appear to be secondary to effects on cigarette consumption, and do not appear to be an independent predictor or cause of reduced cigarette consumption.

Objective: In this study, we assessed cigarette smoking over 12 months among adult former smokers who newly purchased a JUUL Starter Kit (JSK). Methods: Prevalence of past 30-day smoking and factors associated with smoking were assessed among adult (age ≥ 21) former established smokers, stratified as recent (quitting ≤ 12 months) and long-term quitters (> 12 months), who purchased a JSK and completed ≥ 1 of 6 follow-up assessments (N = 4786). Results: Recent quitters had higher rates (16.6%-19.9%) of past 30-day smoking than long-term quitters (6.4%-9.2%) across the 12-month period; smoking prevalence did not significantly increase over time in either subgroup. Few participants (6.5% of recent quitters, 2.8% of long-term quitters) reported smoking at both 9 and 12 months, a pattern that might indicate persistent smoking. Past 30-day JUUL use remained high (≥ 87%) across the 12 months. Participants who used JUUL more frequently were less likely to smoke. Conclusions: Among former smokers who purchased JUUL, prevalence rates of smoking were low and stable across the 12-month period, suggesting there was not a growing cohort of former smokers resuming smoking. Smoking was more common in recent quitters than long-term quitters. Greater use of JUUL was associated with reduced odds of smoking resumption.

Objectives: In this paper, we estimate the prevalence of electronic nicotine delivery systems (ENDS) and JUUL brand ENDS use among adults in the US, overall and by smoking history. Methods: We obtained 2019 cross-sectional online surveys assessing smoking, use of any ENDS, and JUUL specifically, in a national probability sample of 11,833 US adults. Data were analyzed for young adults (YA; aged 18-24) and older adults (OA; aged 25+). Results: Past 30-day ENDS prevalence was 8.0% in YA and 4.7% in OA; equivalent JUUL figures were 3.1% and 1.2%. ENDS/JUUL use was more prevalent among current and former smokers than never smokers, where prevalence was ≤ 2% (YA: 2.0%/0.9%; OA: 0.9%/0.1%). JUUL use was higher among recent (< 1 year) quitters than among long-term (≥ 1 year) quitters. Among those who had ever used both ENDS and other tobacco, strong majorities reported using other tobacco first. Among JUUL users who also had used other tobacco ≥ 95% had used other tobacco first. Conclusions: Past-30-day ENDS use (including JUUL) was ≤ 8% among young adults and ≤ 5% in older adults. Most (> 98%) ENDS and JUUL users were current or former smokers, which is relevant to assessment of the population impact of these products.

Objectives: In this study, we examined complete switching away from cigarettes across various medico-socio-demographic subpopulations of adult smokers who purchased a JUUL Starter Kit (JSK) electronic nicotine delivery system. Methods: We analyzed trajectories of smoking over 12 months in 17,986 adult smokers who purchased a JSK. Populations of special interest were characterized by race/ethnicity, income, diagnoses of potentially smoking-related illness (SRI), depression, and anxiety. Results: Across all 16 subgroups examined, a consistent pattern of trends was observed where complete switching increased, and dual-use decreased over time. Non-Hispanic Asian race/ethnicity, low income, diagnoses of potential SRI, depression, and anxiety were associated with significantly lower switching rates; however, complete switching rates at month 12 were near 50% for all groups, and surpassed the dual-use rates in all subgroups except for those with potential SRI. Conclusions: Substantial rates of complete switching were consistently achieved across all medico-socio-demographic subgroups 12 months following the purchase of the JSK. The potential benefits of switching with JUUL on smokers are likely to be experienced by a wide range of adult smokers.