E-Cigarettes Use Behavior and Experience of Adults: Qualitative Research Findings to Inform E-Cigarette Use Measure Development

Understanding e-Cigarette Addictiveness: Triangulation of Focus Group and Netnographic Data

BACKGROUND

Numerous studies have shown that e-cigarettes are addictive. For example, we previously showed that users of e-cigarette online forums discuss experiences of addiction in a netnographic analysis. However, it is unclear what makes e-cigarettes addictive apart from nicotine. In a focus group analysis, we recently identified 3 unique features of e-cigarettes that users linked to experiences of addiction: the pleasant taste, unobtrusiveness, and unlimited usability of e-cigarettes.

OBJECTIVE

This study aimed to validate the previously identified features of e-cigarette addictive potential by triangulating data from the netnographic analysis and focus group discussions.

METHODS

Drawing on a netnographic analysis of 3 popular, German-language e-cigarette forums, we studied whether experiences of addiction were linked to specific e-cigarette features. We included 451 threads in the analysis that had been coded for addictive experiences in a previous study by our team. First, we conducted a deductive analysis with preregistered codes to determine whether the features of pleasant taste, unobtrusiveness, and unlimited usability were mentioned in relation to the addictive potential of e-cigarettes in the online forums. Second, an inductive approach was chosen to identify further possible addictive features of e-cigarettes.

RESULTS

Our deductive analysis confirmed that the features highlighted in our previous focus group study (pleasant taste, unobtrusiveness, and unlimited usability) were also frequently discussed in online forums in connection to addictive symptoms. In addition, our inductive analysis identified nicotine dosage as a significant feature linked to addiction. Users reported varying their nicotine doses for different reasons, leading to the identification of four distinct user types based on dosing patterns: (1) high doses for intermittent, (2) high doses for constant use, (3) low doses for constant use, and (4) switching between high and low doses depending on the situation.

CONCLUSIONS

Our comprehensive analysis of online forum threads revealed that users' experiences of addiction are linked to 4 specific features unique to e-cigarettes: pleasant taste, unobtrusiveness, unlimited usability, and nicotine dosage. Recognizing these addictive features of e-cigarettes is crucial for designing cessation programs and informing public health policies to reduce the addictiveness of e-cigarettes.

The Normalization of Vaping on TikTok Using Computer Vision, Natural Language Processing, and Qualitative Thematic Analysis: Mixed Methods Study

BACKGROUND

Social media posts that portray vaping in positive social contexts shape people's perceptions and serve to normalize vaping. Despite restrictions on depicting or promoting controlled substances, vape-related content is easily accessible on TikTok. There is a need to understand strategies used in promoting vaping on TikTok, especially among susceptible youth audiences.

OBJECTIVE

This study seeks to comprehensively describe direct (ie, explicit promotional efforts) and indirect (ie, subtler strategies) themes promoting vaping on TikTok using a mixture of computational and qualitative thematic analyses of social media posts. In addition, we aim to describe how these themes might play a role in normalizing vaping behavior on TikTok for youth audiences, thereby informing public health communication and regulatory policies regarding vaping endorsements on TikTok.

METHODS

We collected 14,002 unique TikTok posts using 50 vape-related hashtags (eg, #vapetok and #boxmod). Using the k-means unsupervised machine learning algorithm, we identified clusters and then categorized posts qualitatively based on themes. Next, we organized all videos from the posts thematically and extracted the visual features of each theme using 3 machine learning-based model architectures: residual network (ResNet) with 50 layers (ResNet50), Visual Geometry Group model with 16 layers, and vision transformer. We chose the best-performing model, ResNet50, to thoroughly analyze the image clustering output. To assess clustering accuracy, we examined 4.01% (441/10,990) of the samples from each video cluster. Finally, we randomly selected 50 videos (5% of the total videos) from each theme, which were qualitatively coded and compared with the machine-derived classification for validation.

RESULTS

We successfully identified 5 major themes from the TikTok posts. Vape product marketing (1160/10,990, 8.28%) reflected direct marketing, while the other 4 themes reflected indirect marketing: TikTok influencer (3775/14,002, 26.96%), general vape (2741/14,002, 19.58%), vape brands (2042/14,002, 14.58%), and vaping cessation (1272/14,002, 9.08%). The ResNet50 model successfully classified clusters based on image features, achieving an average F1-score of 0.97, the highest among the 3 models. Qualitative content analyses indicated that vaping was depicted as a normal, routine part of daily life, with TikTok influencers subtly incorporating vaping into popular culture (eg, gaming, skateboarding, and tattooing) and social practices (eg, shopping sprees, driving, and grocery shopping).

CONCLUSIONS

The results from both computational and qualitative analyses of text and visual data reveal that vaping is normalized on TikTok. Our identified themes underscore how everyday conversations, promotional content, and the influence of popular figures collectively contribute to depicting vaping as a normal and accepted aspect of daily life on TikTok. Our study provides valuable insights for regulatory policies and public health initiatives aimed at tackling the normalization of vaping on social media platforms.

In Utero Exposure to Maternal Electronic Nicotine Delivery System use Demonstrate Alterations to Craniofacial Development

OBJECTIVE

Develop a model for the study of Electronic Nicotine Device (ENDS) exposure on craniofacial development.

DESIGN

Experimental preclinical design followed as pregnant murine dams were randomized and exposed to filtered air exposure, carrier exposure consisting of 50% volume of propylene glycol and vegetable glycine (ENDS Carrier) respectively, or carrier exposure with 20 mg/ml of nicotine added to the liquid vaporizer (ENDS carrier with nicotine).

SETTING

Preclinical murine model exposure using the SciReq exposure system.

PARTICIPANTS

C57BL6 adult 8 week old female pregnant mice and exposed in utero litters.

INTERVENTIONS

Exposure to control filtered air, ENDS carrier or ENDS carrier with nicotine added throughout gestation at 1 puff/minute, 4 h/day, five days a week.

MAIN OUTCOME MEASURES

Cephalometric measures of post-natal day 15 pups born as exposed litters.

RESULTS

Data suggests alterations to several facial morphology parameters in the developing offspring, suggesting electronic nicotine device systems may alter facial growth if used during pregnancy.

CONCLUSIONS

Future research should concentrate on varied formulations and exposure regimens of ENDS to determine timing windows of exposures and ENDS formulations that may be harmful to craniofacial development.

Illness representations of vaping associated lung injury (VALI) and E-cigarette use: common sense model of self-regulation driven mixed-method approach

OBJECTIVE

The study explored differences in illness representations of VALI guided by the Common-Sense Model of Self-Regulation (CSM-SR) among non-patient adults.

DESIGN

We employed a cross-sectional concurrent mixed-methods design. In the quantitative analysis, we used multivariate analysis of covariance (MANCOVA). Immersion/crystallization was used to analyze qualitative data.

MAIN OUTCOME MEASURES

We measured differences in illness representations of VALI by e-cigarette use status, gender, and urban/rural residence.

RESULTS

E-cigarette use was associated with illness representations of VALI. Current e-cigarette users discounted the detrimental nature of VALI, compared to former and never e-cigarette users. Gender and urban/rural residence moderated the association between e-cigarette use and illness representation of VALI. In the qualitative analysis, 49.3% respondents reported components of the timeline (e.g. permanent), identity (e.g. shortness of breath), causes (e.g. THC products), consequences (e.g. life-threatening), cure/control (e.g. stop vaping), and worry (e.g. fearful).

CONCLUSION

Perceptions about VALI, such as cure and timeline, were associated with e-cigarettes use. Understanding the context in which adults perceive VALI, such as gender and rurality, may contribute to developing interventions that influence e-cigarette cessation. Future research employing CSM-SR to target strategies for promoting vaping abstinence is warranted.

Electronic cigarette use intensity measurement challenges and regulatory implications

Assessing tobacco use intensity allows researchers to examine tobacco use in greater detail than assessing ever or current use only. Tobacco use intensity measures have been developed that are specific to tobacco products, such as asking smokers to report number of cigarettes smoked per day. However, consensus on electronic cigarette use intensity measures that can be used for survey research has yet to be established due to electronic cigarette product and user behavior heterogeneity. While some survey measures that attempt to assess electronic cigarette use intensity exist, such as examining number of 'times' using an electronic cigarette per day, number of puffs taken from an electronic cigarette per day, volume of electronic cigarette liquid consumed per day, or nicotine concentration of electronic cigarette liquid, most measures have limitations. Challenges in electronic cigarette measurement often stem from variations across electronic cigarette device and liquid characteristics as well as the difficulty that many electronic cigarette users have regarding answering questions about their electronic cigarette device, liquid, or behavior. The inability for researchers to measure electronic cigarette use intensity accurately has important implications such as failing to detect unintended consequences of regulatory policies. Development of electronic cigarette use intensity measures, though not without its challenges, can improve understanding of electronic cigarette use behaviors and associated health outcomes and inform development of regulatory policies.

An examination of electronic nicotine delivery system use among college students using social cognitive theory

Objective: Using social cognitive theory as a framework, this study examined electronic nicotine delivery systems (ENDS) use, related cognitions, and context among college students. Participants: Respondents were 1229 students attending a mid-sized, northeastern university. Methods: A cross-sectional survey was administered and SPSS was used for analysis. Results: Almost 41% of respondents reported ENDS use in the prior month (past-month user), 26.8% reported trying ENDS but no use in the prior month (occasional user), and 32.3% reported never trying ENDS. The results highlight significant associations in past-month versus occasional use and reasons for initation, location for ENDS use, perceived norms for ENDS use, and outcome expectations for ENDS use. Conclusions: This study highlights a need for theory-based, multi-level strategies to reduce ENDS use. Interventions should increase awareness about the risks of ENDS, include peer-based interventions to foster health-promoting campus social environments, and explore the use of policies restricting campus ENDS use.

General and Device-Specific Reasons for ENDS Use: A Qualitative Study with Adult ENDS Users

BACKGROUND

A scientific consensus on the public health impact of electronic nicotine delivery systems (ENDS) remains elusive. This is partly due to the wide variation in product characteristics often lumped together under one category. Research is needed to better understand what ENDS device type characteristics motivate their use by adults.

METHODS

Nine focus groups of 32 current ENDS users who were 18+ years old, had used ENDS in the previous 30 days, and had been using ENDS for more than two months were held either in person or online between February and June 2020.

RESULTS

Participants' reasons for their choice of ENDS characteristics included both general, applying to all ENDS products, and specific, relating to particular ENDS devices. Health benefits and the lack of offensive odor were commonly identified as important reasons for using ENDS in general. Flavor and product discreteness were both general and device-specific determinants of ENDS use. Conversely, nicotine delivery, cloud size, battery properties, aesthetics, ease of use, and cost were device-specific drivers of participants' choice.

CONCLUSIONS

The reasons that adults choose to use ENDS are complex and sometimes related to both ENDS as a category and as specific ENDS product types. Regulations and public communication campaigns should reflect their ultimate objective and consider both general and specific motivations when attempting to achieve public health objectives.

Predictors of perceived success in quitting smoking by vaping: A machine learning approach

Prior research has suggested that a set of unique characteristics may be associated with adult cigarette smokers who are able to quit smoking using e-cigarettes (vaping). In this cross-sectional study, we aimed to identify and rank the importance of these characteristics using machine learning. During July and August 2019, an online survey was administered to a convenience sample of 889 adult smokers (age ≥ 20) in Ontario, Canada who tried vaping to quit smoking in the past 12 months. Fifty-one person-level characteristics, including a Vaping Experiences Score, were assessed in a gradient boosting machine model to classify the status of perceived success in vaping-assisted smoking cessation. This model was trained using cross-validation and tested using the receiver operating characteristic (ROC) curve. The top five most important predictors were identified using a score between 0% and 100% that represented the relative importance of each variable in model training. About 20% of participants (N = 174, 19.6%) reported success in vaping-assisted smoking cessation. The model achieved relatively high performance with an area under the ROC curve of 0.865 and classification accuracy of 0.831 (95% CI [confidence interval] 0.780 to 0.874). The top five most important predictors of perceived success in vaping-assisted smoking cessation were more positive experiences measured by the Vaping Experiences Score (100%), less previously failed quit attempts by vaping (39.0%), younger age (21.9%), having vaped 100 times (16.8%), and vaping shortly after waking up (15.8%). Our findings provide strong statistical evidence that shows better vaping experiences are associated with greater perceived success in smoking cessation by vaping. Furthermore, our study confirmed the strength of machine learning techniques in vaping-related outcomes research based on observational data.

A thematic analysis of smokers' and non-smokers' accounts of E-cigarettes

This study explored smokers' and non-smokers' accounts of E-cigarettes. A total of 51 UK-based participants, 20 men and 31 women, responded to open-ended questions online. Inductive thematic analysis identified that the factors that influence E-cigarette behaviour and opinion in adult smokers and non-smokers are related to social context, informative sources, practical aspects and health implications. Participants presented varying accounts of E-cigarettes, suggesting that individual narratives regarding E-cigarettes are multi-faceted. This is important information for health professionals and policy makers tasked with advising on E-cigarette use.

E-Cigarette Use: Device Market, Study Design, and Emerging Evidence of Biological Consequences

Electronic cigarettes are frequently viewed as a safer alternative to conventional cigarettes; however, evidence to support this perspective has not materialized. Indeed, the current literature reports that electronic cigarette use is associated with both acute lung injury and subclinical dysfunction to the lung and vasculature that may result in pathology following chronic use. E-cigarettes can alter vascular dynamics, polarize innate immune populations towards a proinflammatory state, compromise barrier function in the pulmonary endothelium and epithelium, and promote pre-oncogenic phenomena. This review will summarize the variety of e-cigarette products available to users, discuss current challenges in e-cigarette study design, outline the range of pathologies occurring in cases of e-cigarette associated acute lung injury, highlight disease supporting tissue- and cellular-level changes resulting from e-cigarette exposure, and briefly examine how these changes may promote tumorigenesis. Continued research of the mechanisms by which e-cigarettes induce pathology benefit users and clinicians by resulting in increased regulation of vaping devices, informing treatments for emerging diseases e-cigarettes produce, and increasing public awareness to reduce e-cigarette use and the onset of preventable disease.

An investigation of factors encouraging and deterring EC use: a thematic analysis of accounts from UK adults

OBJECTIVE

This study aimed to explore E-cigarette (EC) accounts from a small sample of UK adults with varied smoking/EC experiences. This was to contribute to existing knowledge of adult perceptions and understand the factors that encourage or deter use to inform health messaging aimed at professionals, policy makers and the general public.

DESIGN

Twelve participants, five men and seven women aged 23-55 years (mean age 32.43) with mixed smoking/EC backgrounds took part in face-to-face interviews, analysed using semantic-level inductive thematic analysis.

RESULTS

The analysis identified three key themes. Social influence (1) relates to the understanding of the social representations of ECs. Representation and knowledge (2) captures the impact of varied EC related communication on perception. Aspects of addiction (3) conveys aspects of nicotine addiction and how this influences EC use.

CONCLUSION

ECs were generally perceived as more socially acceptable than cigarettes by non-smokers, although there were varying levels of acceptability depending on the type of EC device used. There was also unanimity concerning uncertainty surrounding the devices. Behavioural/sensory elements and personal enjoyment of ECs were consistent elements that encouraged or deterred use. Although non-smokers/vapers did not use the devices, they expressed similar apprehensions to those who did.

Volatile aldehyde emissions from "sub-ohm" vaping devices

"Sub-ohm" atomizers with reduced resistance can deliver more power than conventional electronic cigarettes. Typical battery outputs are 100 W or more. These devices are particularly popular among young users, and can be a significant source of volatile carbonyls in the indoor environment. Emissions from next-generation sub-ohm vaping products were characterized by determining e-liquid consumption and volatile aldehydes emissions for several combinations of popular high-power configurations. Tests explored the effect of dilution air flow (air vent opening), puffing volume, and coil assembly configuration. The mass of liquid consumed per puff increased as the puff volume increased from 50 to 100 mL, then remained relatively constant for larger puff volumes up to 500 mL. This is likely due to mass transfer limitations at the wick and coil assembly, which reduced the vaporization rate at higher puff volumes. Carbonyl emission rates were systematically evaluated using a 0.15 Ω dual coil atomizer as a function of the puffing volume and dilution air flow, adjusted by setting the air vents to either 100% (fully open), 50%, 25%, or 0% (closed). The highest formaldehyde emissions were observed for the lowest puff volume (50 mL) when the vents were closed (48 ng mg^-1), opened at 25% (39 ng mg^-1) and at 50% (32 ng mg^-1). By contrast, 50-mL puffs with 100% open vents, and puff volumes >100 mL for any vent aperture, generated formaldehyde yields of 20 ng mg^-1 or lower, suggesting that a significant cooling effect resulted in limited carbonyl formation. Considering the effect of the coil resistance when operated at a voltage of 3.8 V, the amount of liquid evaporated per puff decreased as the resistance increased, in the order of 0.15 Ω > 0.25 Ω > 0.6 Ω, consistent with decreasing aerosol temperatures measured at the mouthpiece. Three different configurations of 0.15 Ω coils (dual, quadruple and octuple) were evaluated, observing significant variability. No clear trend was found between carbonyl emission rates and coil resistance or configuration, with highest emissions corresponding to a 0.25 Ω dual coil atomizer. Carbonyl emission rates were compared with those determined using the same methodology for conventional e-cigarettes (lower power tank systems), observing overall lower yields for the sub-ohm devices.

Qualitative insights on how adult e-cigarette users describe quantity of e-cigarettes used - PATH Study 2018

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A variety of approaches were used to describe quantity across device types.

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The most common approach was number of times/puffs per day, but specificity varied.

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Some described quantity in device-specific terms (cartridge/pod, device, e-liquid).

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Tank users varied in how they described quantity of e-liquid used.

The purpose of this qualitative study was to gain a deeper understanding of how adult e-cigarette users describe quantity of e-cigarettes used. Data for this analysis came from a qualitative study of U.S. adult dual e-cigarette and cigarette users and former cigarette smokers aged 18 years and older. Eligible respondents from Wave 4 (2016–2017) of the Population Assessment of Tobacco and Health (PATH) Study responded to a brief web questionnaire and participated in an in-depth telephone interview (n = 112) between March and August 2018. Using the respondent’s native terminology for their e-cigarette device, interviewers asked respondents to describe in their own words the quantity of e-cigarettes used. Using NVivo software, interview transcripts were coded and analyzed to identify themes and patterns. Respondents described quantity used in three different ways: number of times and/or puffs; device-specific terms (i.e., replacement of disposable devices, cartridges/pods; use of e-liquid); and perceived equivalence to a quantity of traditional cigarettes. The most commonly reported approach across all device types and levels of device proficiency, although with varying ease and specificity, was the number of times and/or puffs taken in a day. Several respondents used multiple approaches to describe quantity. E-cigarette users use a variety of approaches to describe quantity of e-cigarette used, contributing to challenges developing standardized survey measures. The variety of approaches should be taken into consideration along with device type and other contextual factors such as device proficiency when developing survey questions.

Real-world vaping experiences and smoking cessation among cigarette smoking adults

INTRODUCTION

E-cigarettes may have the potential to be an effective cessation aid for some cigarette smokers. However, the extent to which smokers' experiences using e-cigarettes (vaping) to quit smoking impact their cessation outcomes is unclear. In this cross-sectional survey study, we develop a multidimensional measure of vaping experiences in adults who quit smoking by vaping and test its association with perceived success in smoking cessation.

METHODS

In 2019, recruitment invitations were emailed to adult past-year smokers who had accessed cessation services across Ontario, Canada. Respondents who tried vaping to quit smoking in the past year completed a detailed online survey. Factor analysis was performed on ratings of 45 vaping experiences items to identify dimensions of vaping experiences. Factor scores were entered into logistic regressions to test if vaping experiences dimensions had differential impact on perceived success in smoking cessation.

RESULTS

Of the 889 participants, 56.0% were female, 81.1% were Caucasian, and the mean age was 37.7 ± 11.9 years. Twenty percent (19.6%) reported having successfully quit smoking by vaping in the past year. Among the six vaping experiences factors, better experiences in five factors-Relationships, Flexibility of Vaping, Side Effects, Vaping Devices, and Sensory Functions-were each independently and positively associated with improved odds of successful quitting. Notably, Relationships [OR = 2.01, 95% CI: 1.61-2.64] and Side Effects [OR = 1.95; 95% CI 1.54-2.29] were the strongest correlates of perceived success in smoking cessation.

CONCLUSIONS

These findings indicate an opportunity to increase cessation rates by improving the experiences of smokers who vape to quit smoking.

'I perceive it to be less harmful, I have no idea if it is or not:' a qualitative exploration of the harm perceptions of IQOS among adult users

BACKGROUND

Harm perceptions of tobacco and nicotine products can influence their use and could be targeted by policies to change behaviour. IQOS was introduced to the UK in 2016, and there is little independent qualitative research on IQOS harm perceptions. This study explored the perceived health harms of IQOS to users and those exposed to the emissions, what shapes these perceptions, and what participants wanted to know about the harms of IQOS.

METHODS

Qualitative interviews in London, UK, with 30 adult current and former IQOS users who currently smoked or quit smoking in the last 2 years.

RESULTS

IQOS was perceived as less harmful than smoking but not risk-free, although there was great uncertainty. Influences on harm perceptions were consolidated into six themes: (1) dominance of manufacturer claims influenced perceptions that IQOS is less harmful than smoking to users and those around them, although mistrust of the tobacco industry heightened scepticism about harms; (2) limited independent and long-term research led to uncertainty about harms, although some participants trusted IQOS would not be marketed if it were very harmful. Participants wanted more independent and long-term studies into harm; (3) appearance of HEETS (tobacco sticks) packaging conveyed reduced harm because packets were 'pretty', without graphic/specific warnings, although written warnings conveyed some harm. Participants wanted more information on HEETS packets about harms; (4) process of heating and HEETS contents-heating, compared with burning, tobacco was perceived to produce fewer harmful chemicals, while tobacco, nicotine, and chemicals in HEETS were perceived to cause some harm. Participants wanted clarification about the harms of heating tobacco and HEETS ingredients; (5) improvements in physical health and personal appearance reduced perceptions of harm; (6) differences in sensory experiences (taste, sight, smell) when using IQOS over smoking reduced perceptions of harm, while 'black' deposits inside IQOS led to perceptions of some harm. Reduced volume and smell of IQOS emissions also reduced perceptions of harm to non-users exposed to the emissions.

CONCLUSIONS

IQOS was perceived as less harmful than smoking but not risk-free, although there was great uncertainty. Participants wanted clarification about IQOS harms from independent sources in accessible forms, specifically related to HEETS ingredients, heating tobacco, and emissions to others.

Critical challenges and creative solutions for quantifying nicotine vaping: qualitative reports from young adults

BACKGROUND

Previous studies suggest that young adults who vape nicotine experience difficulty when answering survey items assessing quantity of vaping. The current study asked young adults who vape to provide suggestions for improving the scientific measurement of vaping.

METHODS

We conducted semi-structured qualitative interviews with 62 young adults who vape in Los Angeles, California between June 2018 and June 2019. We analyzed participants' responses to the following question: "What do you think is the best way for us to understand how much people vape?" using thematic content analysis.

RESULTS

We identified two major themes: (1) challenges stemming from differences between the way researchers query about vaping and how individuals self-monitor vaping frequency, and (2) insights for future measurement of vaping. Participants reported that challenges of accurately quantifying vaping were due to inherently hard-to-answer questions (e.g., puffs per day), lack of awareness of or not actively monitoring consumption of vaping products, or because vaping behaviors vary considerably between and within individuals over time, making "on-average" questions challenging. Participants discussed ideas for improving survey measures that could accurately assess vaping quantity, including querying about type of device used, and frequency of replenishment of nicotine solutions.

CONCLUSION

Existing vaping behavior survey measures may not accurately capture quantity of vaping as they differ from how (or if) participants track their own vaping consumption patterns. While continued research is needed to optimally refine survey measures on vaping consumption, future measures may better align with vapers' self-monitoring by including questions on device-type and replenishment frequency.

Vaping and E-Cigarettes Within the Evolving Tobacco Quitline Landscape

This article summarizes the vaping research literature as it pertains to tobacco quitlines and describes vaping assessment, treatment, and evaluation quitline practices. It also presents 2014-2018 registration data (vaping in the past 30 days, number of use days, use for quitting smoking, and intentions to quit vaping) from 24 public quitlines (23 states and District of Columbia) and 110,295 enrollees to employer-sponsored quitlines. Trends in vaping rates over time, by state, and by age group are described. Approximately 57,000 adult public quitline enrollees in the U.S. reported vaping at registration in 2018 (14.7% of enrollees). Most quitline participants who vape also smoke cigarettes and contact the quitline for smoking cessation support. Rates of reporting vaping and no combustible or smokeless tobacco use in the past 30 days are 0.5% of all public quitline participants (<3% of public quitline vaping product users). Data are not systematically available regarding the number of quitline participants who are seeking help quitting vaping and only vape (do not use combustible or smokeless tobacco). Few quitline participants (<1%) are youth aged <18 years, but more than a third (35%) report vaping. This paper outlines research and evaluation priorities to inform the future quitline treatment landscape with respect to vaping. The quitline community is positioned to increase the likelihood that vaping has a positive impact for adults who smoke through harm reduction or supporting cessation and has opportunities to expand impacts on youth and young adult vaping prevention and cessation.

Simultaneous Use of Alcohol and Electronic Nicotine Delivery Systems among College Students: Vaping History, Motivations for Use, and Outcome Expectancies

Introduction: Simultaneous polydrug use of electronic nicotine delivery systems (ENDS) and alcohol among college students is not well understood despite high rates of vaping and alcohol use among this population. The current study examined rates of simultaneous use and compared demographic characteristics, vaping history, motivations for initiating use, and outcome expectancies based on polydrug use status. Methods: An online and paper-and pencil questionnaire was administered to undergraduate students at a university in the northeast of the U.S. Purposive sampling strategies were used and a raffle was offered to incentivize participation. Results: Simultaneous polydrug use was prevalent in the sample of 670 college students, with 55.6% reporting simultaneous and non-simultaneous use, 34.0% reporting simultaneous use only, and 10.4% reporting non-simultaneous use only. An examination of differences based on polydrug use status indicated that students who reported simultaneous and non-simultaneous use were more likely to be males, report vaping daily, and endorse a wide range of motivations for use. Students who engaged in simultaneous use only were more likely to be females, indicate a social contextual-related motivation for initiating use, and had higher scores on appetite control, emotion regulation, and taste sensation outcome expectancies. Students who engaged in non-simultaneous use only were more likely to be nonwhite students and report the lowest expectation of health risks. Conclusions: The findings reveal differences based on simultaneous polydrug use status that can be informative in the development of contextually relevant prevention programming. Future research is needed to further explore simultaneous use of ENDS and alcohol.

Effects of Negative Emotion on Abstinence Induced Change in Urge to Vape and Measures of Vaping Dependence

INTRODUCTION

Negative emotion and craving to smoke are established factors driving the maintenance of combustible cigarette use and dependence. The current study aimed to examine whether these findings extend to e-cigarette use. Toward that aim, change in vaping urge following abstinence was examined as a function of negative emotion. Additionally, a mediation model which previously demonstrated relationships between negative emotion, craving, and combustible cigarette dependence was tested in e-cigarette users.

METHOD

Daily e-cigarette users (N = 32, M_age = 21 years, SD_age = 7 years; 78% white) completed a battery of psychological, behavioral, and smoking-related measures in a human laboratory setting. Using their personal devices, participants completed a 5-minute ad-libitum vaping session, a baseline measure of vaping urge, followed by a 2-hour observed abstinence period and a final assessment of vaping urge.

RESULTS

Multivariate regression and two mediation models were utilized to examine factors associated with vaping dependence. The results of these models indicated that negative affect predicted vaping urge following observed abstinence. The relationship between negative affect and measures of vaping dependence and habit, respectively, were significantly mediated by changes in urge during the abstinence period.

CONCLUSIONS

These preliminary results indicate that psychological constructs underlying vaping dependence are similar to those previously found to be associated with combustible cigarette dependence. Further research examining whether these constructs, namely negative affect and change in urge following abstinence, will be important variables to target for vaping cessation treatments is needed.

Electronic Cigarette Use Among Youth: Understanding Unique Risks in a Vulnerable Population

PURPOSE OF REVIEW

This review discusses prevalence rates of electronic (e-)cigarette use among youth and factors that likely contribute to their growing popularity among this population. Trends shaping the e-cigarette landscape, the appeal of e-cigarettes among youth, perceptions contributing to the initiation of e-cigarettes, available assessments capturing the usage of and attitudes towards e-cigarettes, and e-cigarette policies and regulations are reviewed.

RECENT FINDINGS

E-cigarette use among this vulnerable group may relate to factors associated with the promotion of social status, individuality, and enjoyment, along with low perceptions of risk and harm. Measures assessing factors unique to e-cigarette use among youth (e.g., individuality) still need to be developed and validated. Effects of existing regulations to limit youth access to e-cigarettes may be limited, and shortcomings of current policy measures are discussed with recommendations.

SUMMARY

The rise of e-cigarette use among youth culminated through a perfect storm of clever marketing targeting youth appeal, innovations in more effective nicotine delivery systems, capitalizing on increased susceptibility of the adolescent brain, and regulatory gaps. Understanding risk and protective factors specific to this vulnerable group, which can be gleaned in part by psychometrically valid assessments, could inform regulatory strategies and prevention programming efforts. Yet, few validated measures exist that assess attitudes, behaviors, and patterns of e-cigarette use that are specific to youth. Ultimately, it is incumbent upon policymakers to create comprehensive regulations that prioritize harm reduction and can evolve in lockstep with the constantly changing e-cigarette product landscape.

Early Cardiovascular Risk in E-cigarette Users: the Potential Role of Metals

PURPOSE OF REVIEW

Electronic cigarettes (e-cigs) are a source of metals. Epidemiologic and experimental evidence support that metals are toxic to the cardiovascular system. Little is known, however, about the role that e-cig metals may play as toxicants for the possible cardiovascular effects of e-cig use. The goal of this narrative review is to summarize the evidence on e-cig use and metal exposure and on e-cig use and cardiovascular toxicity and discuss the research needs.

RECENT FINDINGS

In vitro studies show cytotoxicity and increased oxidative stress in myocardial cells and vascular endothelial cells exposed to e-liquids and e-cig aerosols, with effects partially reversed with antioxidant treatment. There is some evidence that the heating coil plays a role in cell toxicity. Mice exposed to e-cigs for several weeks showed higher levels of oxidative stress, inflammation, platelet activation, and thrombogenesis. Cross-over clinical experiments show e-cig use alters nitric oxide-mediated flow-mediated dilation, endothelial progenitor cells, and arterial stiffness. Cross-sectional evidence from large nationally representative samples in the USA support that e-cig use is associated with self-reported myocardial infarction. Smaller studies found associations of e-cig use with higher oxidized low-density protein and heart variability compared to healthy controls. Numerous studies have measured elevated levels of toxic metals in e-cig aerosols including lead, nickel, chromium, and manganese. Arsenic has been measured in some e-liquids. Several of these metals are well known to be cardiotoxic. Numerous studies show that e-cigs are a source of cardiotoxic metals. Experimental studies (in vitro, in vivo, and clinical studies) show acute toxicity of e-cigs to the vascular system. Studies of long-term toxicity in animals and humans are missing. Longitudinal studies with repeated measures of metal exposure and subclinical cardiovascular outcomes (e.g., coronary artery calcification) could contribute to determine the long-term cardiovascular effects of e-cigs and the potential role of metals in those effects.

Effect of free-base and protonated nicotine on nicotine yield from electronic cigarettes with varying power and liquid vehicle

Nicotine in electronic cigarette (ECIG) liquids can exist in a free-base or protonated (or "salt") form. Protonated nicotine is less aversive upon inhalation than free-base nicotine, and many ECIG manufacturers have begun marketing protonated nicotine products, often with high nicotine concentrations. Regulations intended to control ECIG nicotine delivery limit nicotine concentration but do not consider nicotine form. In this study, we systematically examined the effect of nicotine form on nicotine yield for varying powers and liquid vehicles. A Kanger Subox Mini-C tank ECIG (0.5 Ω) was used to generate aerosols at varying powers (5-45 W) from liquid solutions that contained either free-base or protonated nicotine at 15 mg/g concentration, with a liquid vehicle consisting of either propylene glycol (PG) or vegetable glycerin (VG), resulting in four different solutions (free-base/PG, free-base/VG, protonated/PG, and protonated/VG). Nicotine yield was quantified using gas chromatography-mass spectrometry. Nicotine yields were not influenced by nicotine form under any condition investigated. At each power level, PG-based liquids resulted in approximately double the nicotine yield of VG-based liquids. Nicotine concentrations in the aerosols matched those of the parent liquids for both the PG and VG conditions. Increasing power led to greater nicotine yield across all conditions. The amount of nicotine emitted by an ECIG is independent of whether the nicotine is free-base or protonated, however the liquid vehicle has a strong effect on yield. Regulations intended to limit nicotine emissions must consider not only nicotine concentration, but also liquid vehicle and device power.

Research on Youth and Young Adult Tobacco Use, 2013-2018, From the Food and Drug Administration-National Institutes of Health Tobacco Centers of Regulatory Science

The Tobacco Regulatory Science Program is a collaborative research effort between the National Institutes of Health (NIH) and the Food and Drug Administration (FDA). In 2013, the NIH funded 14 Tobacco Centers of Regulatory Science (TCORS), which serve as partners in establishing research, training, and professional development programs to guide FDA. Each of the fourteen TCORS, and two other NIH-funded research programs, the Center for the Evaluation of Nicotine in Cigarettes (CENIC) and the Consortium on Methods Evaluating Tobacco (COMET), pursued specific research themes relevant to FDA's priorities. A key mandate for FDA is to reduce tobacco use among young people. This article is a review of the peer-reviewed research, including published and in-press manuscripts, from the TCORS, CENIC, and COMET, which provides specific data or other findings on youth (ages 10-18 years) and/or young adults (ages 18-34 years), from 2013 to 2018. Citations of all TCORS, CENIC, and COMET articles from September 2013 to December 2017 were collected by the TCORS coordinating center, the Center for Evaluation and Coordination of Training and Research. Additional citations up to April 30, 2018 were requested from the principal investigators. A scoring rubric was developed and implemented to assess study type, primary theme, and FDA priority area addressed by each article. The major subareas and findings from each priority area are presented. There were 766 articles in total, with 258 (34%) focusing on youth and/or young adults. Findings relevant to FDA from this review concern impact analysis, toxicity, health effects, addiction, marketing influences, communications, and behavior.

IMPLICATIONS

The Tobacco Centers of Regulatory Science, CENIC, and COMET have had a high output of scientific articles since 2013. These Centers are unique in that the FDA supports science specifically to guide future regulatory actions. The 258 articles that have focused on youth and/or young adults are providing data for regulatory actions by the FDA related to the key priority areas such as the addictiveness of non-cigarette products, the effects of exposure to electronic cigarette marketing on initiation and cessation, and the impact of flavored products on youth and young adult tobacco use. Future regulations to reduce tobacco use will be guided by the cumulative evidence. These Centers are one innovative mechanism to promote important outcomes to advance tobacco regulatory science.

Twenty-four-hour subjective and pharmacological effects of ad-libitum electronic and combustible cigarette use among dual users

BACKGROUND AND AIMS

Relative pharmacological effects of e-cigarettes and cigarettes during 24 hours of ad-libitum use have not been described. In this study, 24-hour blood plasma nicotine concentrations and 48-hour subjective effects with use of cigarettes and e-cigarettes were measured among dual users.

DESIGN

Two-arm within-subject cross-over design with preferred e-cigarette or cigarette ad-libitum use over 48 hours.

SETTING

Hospital research ward in San Francisco, California, USA.

PARTICIPANTS

Thirty-six healthy dual users of e-cigarettes and cigarettes (n = 8, 25% females).

MEASUREMENTS

Twenty-four-hour blood plasma nicotine and cotinine concentrations and 48-hour self-reported nicotine withdrawal symptoms and rewarding effects.

FINDINGS

Analyses used analysis of variance (ANOVA)-based mixed models with order of product (e-cigarette or cigarette) and product type (combustible cigarette or type of e-cigarette) as fixed effects, and subject as a repeated effect. During a 24-hour period, e-cigarettes produced lower nicotine exposure than cigarettes for the majority of users, although 25% received more nicotine from e-cigarettes, which was predicted by more frequent e-cigarette use or greater dependence. Compared to cigarette smoking, nicotine exposure for variable-power tank users was similar, while cig-a-like (t₍₃₀₎  = 2.71, P = 0.011, d = 0.745) and fixed-power tank users (t₍₃₀₎  = 3.37, P = 0.002, d = 0.993) were exposed to less nicotine. Cigarettes were rated higher than e-cigarettes on some desirable subjective effects (e.g. psychological reward, t₍₃₂₂₎  = 7.24 P < 0.001, d = 0.432), but withdrawal symptom reduction was comparable. No differences were found between e-cigarette types, but Bayes factors indicate that these measures were insensitive.

CONCLUSIONS

During a 24-hour period in a hospital setting in the United States, nicotine exposure for dual users of e-cigarettes and cigarettes was similar when using cigarettes or variable-power tank devices only but was lower for those using cig-a-like or fixed-power devices only. Despite lower nicotine levels, all types of e-cigarette were effective in preventing withdrawal symptoms. E-cigarettes were rated less rewarding than cigarettes.

The role of E-liquid vegetable glycerin and exhaled aerosol on cue reactivity to tank-based electronic nicotine delivery systems (ENDS)

RATIONALE

Electronic nicotine delivery systems (ENDS or e-cigarettes) share salient features of combustible smoking, such as inhalation and exhalation behaviors, and evidence indicates that first- and second-generation ENDS generalize as smoking cues. The present study examined whether newer, tank-based third-generation ENDS ("mods") also evoke smoking urges, and whether enhancing the visibility of exhaled aerosol clouds-by increasing the e-liquid vegetable glycerin (VG) content-strengthens the cue salience of ENDS.

OBJECTIVES

The objective was to assess the role of exhaled aerosol clouds on ENDS cue potency using a standardized laboratory paradigm designed to mimic real-world exposures.

METHODS

Using a mixed design, young adult smokers (n = 50; mean age 26.5 years; ≥ 5 cigarettes/day) observed a study confederate drinking bottled water (control cue) and vaping an ENDS mod containing e-liquid with either high (73%) or low (0%) VG. Participants completed the Brief Questionnaire on Smoking Urges (BQSU) and visual analog scales (VAS) assessing cigarette and e-cigarette desire pre- and post-cue exposure.

RESULTS

Increasing the e-liquid content of VG enhanced the size and visibility of the exhaled aerosol clouds and evoked a greater increase in smoking desire and a more sustained increase in e-cigarette desire relative to the low VG cue. Both cues elicited increases in smoking urges. These results remained after controlling for sex, prior ENDS experience, recent smoking behavior, and menthol preference.

CONCLUSIONS

Observation of tank-based ENDS use generalizes as a smoking cue and its cue salience is strengthened by increasing the e-liquid content of VG to enhance the visibility of the exhaled aerosol cloud.

A Review of the Use and Appeal of Flavored Electronic Cigarettes

PURPOSE OF REVIEW

E-cigarettes are available in a variety of flavors not found in traditional tobacco products (i.e., "nontraditional flavors"), which is a commonly-cited reason for e-cigarette use. This review examines the prevalence of nontraditional-flavored e-cigarette use, mechanisms through which flavorings enhance product appeal, use of nontraditional-flavored e-cigarettes for smoking cessation, and differences in these findings between youth and adults.

RECENT FINDINGS

Nontraditional-flavored e-cigarettes are used at e-cigarette initiation by the majority of youth. These flavors enhance the appeal of e-cigarettes by creating sensory perceptions of sweetness and coolness and masking the aversive taste of nicotine. Use of nontraditional-flavored e-cigarettes is higher among youth and young adults (vs. older adults) and among nonsmokers (vs. combustible cigarette smokers).

SUMMARY

Nontraditional-flavored e-cigarettes are popular among youth, but may be less common among older adults and combustible cigarette smokers. Further research is needed to determine whether use of e-cigarettes in nontraditional flavors affects smoking cessation.

Measuring characteristics of e-cigarette consumption among college students

Objective: E-cigarette use among college students has increased drastically in recent years. This study aims to inform development of a comprehensive measure of e-cigarette consumption for this population. Participants and Methods: This mixed-method study collected both quantitative and qualitative data from a sample of 43 experienced e-cigarette users from two college campuses, using a self-reported questionnaire and a semi-structured interview, in March-September of 2017. Results: College student users found some of the consumption questions in national surveys difficult to answer. Switching nicotine levels, mixing flavors, co-using with alcohol and marijuana, using with others who were vaping or drinking, and vaping in a car or indoor space were all common. The participants defined "regular user" based on ownership of a device rather than on quantity/frequency. Conclusions: A comprehensive e-cigarette consumption measure should cover the complex characteristics that are potentially associated with negative health consequences such as flavorings, co-use and social contexts.

Development and psychometric validation of a novel measure of sensory expectancies associated with E-cigarette use

INTRODUCTION

E-cigarette dependence measures largely focus on e-cigarette use ("vaping") that is linked to nicotine use, and measures assessing sensory aspects of vaping that may influence use (e.g., taste) are limited in scope. Thus, we developed the novel Sensory E-cigarette Expectancies Scale (SEES).

METHODS

In Summer 2017, 610 adult e-cigarette users (48.7% male, 84.9% White, 37.41[±12.15] years old) completed an online survey that included 23 SEES items. Psychometric analyses included evaluating latent structure, internal consistency, measurement invariance, mean differences, and test-criterion relationships.

RESULTS

Factor analyses supported a 9-item, 3-subscale structure (taste/smell, pleasure/satisfaction, vapor cloud production). Subscales evidenced internal consistency and scalar invariance by sex, race, smoking status (current/not), vaping status (daily/not), e-liquid nicotine content (yes/no), and device type (cig-a-likes/vape-pens/Advanced Personal Vaporizers [APVs]/Mods). Women and daily e-cigarette users reported stronger SEEs for taste/smell and pleasure than their counterparts. Non-white participants reported stronger SEEs for cloud production than White participants. Cig-a-like users reported the weakest SEEs for taste/smell and weaker SEEs linked to cloud production than APV/mod users. SEES scores evidenced convergence with nicotine dependence (mean r = .36). Finally, SEES scores predicted vaping frequency and habitual vaping concurrently and incrementally beyond nicotine dependence.

CONCLUSIONS

The SEES evidenced good psychometric properties, suggesting that the measure can be used to assess sensory vaping expectancies in adults. Importantly, SEES scores indicated that sensory expectancies are related, yet distinct, from nicotine dependence. Future research should evaluate how SEEs relate to product characteristic preferences and patterns of vaping including the development and maintenance of addiction.

Impact of messages about scientific uncertainty on risk perceptions and intentions to use electronic vaping products

BACKGROUND

The science surrounding e-cigarettes and other electronic vaping products (EVPs) is rapidly evolving, and the health effects of vaping are unclear. Little research has explored how individuals respond to information acknowledging scientific uncertainty. The aim of the present study was to understand the impact of messages about scientific uncertainty regarding the health effects of vaping on risk perceptions and behavioral intentions.

METHODS

Adults in an online experiment (n = 2508) were randomly exposed to view either a control message (a short factual statement about EVPs) or an uncertainty message (the control message plus additional information describing why EVP-related research is limited or inconclusive). Participants rated the risks of vaping and their intentions to try or stop vaping.

RESULTS

Individuals who viewed the uncertainty message rated vaping as less risky than those who viewed the control message. Message exposure did not impact intentions to try vaping soon or intentions to stop vaping in the next 6 months.

CONCLUSIONS

Acknowledging scientific uncertainty made EVP use seem less risky. Future research should explore possible drivers of this response, such as deeper message processing or emotional reactions. Researchers and practitioners designing public health campaigns about vaping might consider a cautious approach to presenting information about scientific uncertainty.

Youth generated prevention messages about electronic cigarettes

Rates of e-cigarette use are high among youth, and there is little known about the long-term health effects of e-cigarettes. Since peer influence is a powerful determinant of tobacco use, we aimed to identify message themes about e-cigarettes that youth would use to encourage or discourage peers from using e-cigarettes. We conducted 10 focus groups (N = 69) with non-smokers and smokers from one middle school, high school and college in Connecticut. Participants engaged in a discussion about e-cigarettes, and each participant created one written message to encourage e-cigarette use and one to discourage use among peers. We content-analyzed the messages and identified three main themes and 12 encouraging and discouraging sub-themes. Encouraging themes included health benefits of e-cigarettes relative to cigarettes, attractive product characteristics (e.g. flavors) and social advantages (e.g. positive social image) of using e-cigarettes. Discouraging messages included health risks of e-cigarettes relative to cigarettes, unattractive product characteristics (e.g. cost) and social disadvantages (e.g. negative social image of using an e-cigarette). Overall, there were no differences by sex, age group or smoking status in generation of encouraging and discouraging message themes. This study identified youth-generated themes that may aid in e-cigarette prevention among youth.

Characterizing ENDS use in young adults with ecological momentary assessment: Results from a pilot study

INTRODUCTION

Ecological Momentary Assessment (EMA) allows for assessment of electronic nicotine delivery systems (ENDS) use in real-time. This EMA study aimed to 1) describe study participation rates; 2) evaluate the concordance of EMA and survey items measuring frequency and quantity of ENDS use; and 3) assess the relationships between EMA items measuring frequency and quantity of ENDS use with ENDS dependence, measured at baseline and with saliva cotinine collected at follow-up.

METHODS

Fifty young adult ENDS users completed baseline surveys, EMAs (i.e., random, event-based, daily diaries), and follow-up questionnaires over a 14-day period. Spearman correlations were conducted to determine concordance of survey items. Linear regression models assessed the relationships between EMA ENDS use characteristics (e.g., puffs, number of days used, quantity of e-liquid) with dependence items at baseline and saliva cotinine at follow-up.

RESULTS

Overall completion for the prompted EMAs (random and daily diaries) was 68%. Correlations between EMA measures assessing ENDS use ranged from weak (ρ = -0.02; NS) to strong (ρ = 0.69, p < .001); EMA to follow-up items ranged from weak (ρ = 0.16; p < .05) to moderate (ρ = 0.54; p < .001). Significant associations were found between ENDS use measured via random and daily diary EMAs and saliva cotinine at follow-up after controlling for cigarette smoking (B = 0.70-1.76; p < .01), but not for event-based EMAs. Items measuring frequency/quantity of use from random EMAs were consistently associated with ENDS dependence at baseline (B = 0.74-1.58; p < .01).

CONCLUSION

EMA represents a promising methodology to capture real-time ENDS use behaviors, primarily through daily diary and random EMAs.

Vaping associated with healthy food words: A content analysis of Twitter

E-cigarettes were initially introduced as a less harmful alternative to combustible cigarettes, but marketing efforts may now be exceeding these claims by associating e-cigarettes with words related to healthy foods. These associations could mislead people to assume vaping is a healthy practice. Tweets from January to March 2017 were obtained from the Twitter Streaming Application Programming Interface (API) to assess content about vaping linked to healthy food words. Tweets were classified into one of nine categories along with their source (marketer vs. non-marketer). We content analyzed original English language public postings on Twitter that included vaping-related keywords and at least one of eight co-occurring healthy food-related labels (e.g., 'natural,' 'vitamin,' 'vegan,' and 'organic') (N = 1205). Chi-square analyses compared themes by message source. Findings suggest vaping is being marketed in ways that could paradoxically lead consumers to believe that e-cigarettes are health-enhancing. We found more tweets representing vaping as health-enhancing (9%) than referring to it as a smoking-cessation device (1%). The largest category of tweets referred to vaping as harmless (28%) and therefore compatible with a healthy lifestyle. Tweets presenting vaping as harmless or with a sensation theme were more likely to be authored by marketers than by non-marketers. Food and drug regulation needs to be more vigilant to prevent misleading advertising from e-cigarette marketers.

Regional Rural-Urban Differences in E-Cigarette Use and Reasons for Use in the United States

PURPOSE

To determine whether there are rural/urban differences in e-cigarette use and reasons for use that vary across the 10 Health & Human Services (HHS) regions.

METHODS

Age-adjusted bivariate and multivariable analyses were conducted for n = 225,413 respondents to the 2014-2015 Tobacco Use Supplement-Current Population Survey to estimate the prevalence of e-cigarette use. Reasons for e-cigarette use were collected from n = 16,023 self-respondents who reported ever using e-cigarettes.

FINDINGS

While nationally rural residents appeared more likely to use e-cigarettes, adjusted results indicated that current e-cigarette use was significantly less likely across the northern and western regions (New England, East North Central, Heartland, North Central Mountain, Northwest, and Southwest Pacific regions). Reasons for e-cigarette use differed by urban/rural status and region; for example, the rationale to use e-cigarettes as a smoking cessation aid was significantly more common among rural compared to urban adults in the New England and New York/New Jersey regions, but less common in the Southeast.

CONCLUSIONS

For several regions, there were no significant rural/urban differences in e-cigarette use and reasons for use. Yet those regions that present differences face the need to develop public health approaches to minimize urban/rural disparities in health education, services, and outcomes related to tobacco use, particularly where access to health care is limited. Public health campaigns and guidance for clinical care within HHS regions should be tailored to reflect regional differences in beliefs about e-cigarettes.

E-cigarette use and perceived health change: Better health through vaping?

INTRODUCTION

As e-cigarette use increases, questions about individual and public health effects remain unanswered (e.g. cessation tool, addiction path). Despite increasing use, few studies have focused on vape shop patrons. This study examined whether vape shop patrons believe their health is affected by the use of e-cigs; more specifically, the aim was to evaluate the association between e-cig use, change in tobacco use, and perception of health.

METHODS

A survey of e-cig users (N=78) was conducted in vape shops. Questions included e-cig and traditional tobacco use, health perceptions, and demographics. Descriptive techniques were used to characterize participants as either those who perceived e-cig use improved their health or those who perceived their health unaffected. Logistic regression assessed the association between change in tobacco use, e-cig use, and perception of health effects.

RESULTS

Most reported daily e-cig (91%) and current (11.5%) or former (78.2%) combustible cigarette use. Approximately, three-fourths (76.9%) perceived better health; the remainder (23.1%) perceived unaffected health. Change in cigarette use was significantly associated with perceptions that health is better with e-cig use. Participants who decreased cigarette use by 2-3 cartons/month and more than 3 cartons/month were significantly more likely to indicate that e-cig use has improved their health compared to those who decreased tobacco use by 1.5 cartons or fewer per month (OR=4.35, 95% CI: 1.13-16.9; OR=25.67, 95% CI: 2.97-221.7, respectively).

CONCLUSIONS

The majority of e-cig users perceived better health. Our findings suggest that health campaign designers should carefully assess the scientific uncertainty surrounding the use of these devices and consider means to clearly convey this information. Given the lack of scientific agreement on the health effects of e-cigs and the important role that perceptions play in behavior, health campaign designers, health education practitioners, policy makers, and health care providers should err on the side of caution when advising individuals about e-cig use.

Effects of electronic cigarette liquid solvents propylene glycol and vegetable glycerin on user nicotine delivery, heart rate, subjective effects, and puff topography

BACKGROUND

Electronic cigarettes (ECIGs) are a class of tobacco products that produce different effects (e.g., nicotine delivery), depending on the device, liquid, and behavioral factors. However, the influence of the two primary ECIG liquid solvents, propylene glycol (PG) and vegetable glycerin (VG), on ECIG acute effects is unknown.

METHODS

Thirty ECIG-experienced, ≥12-h nicotine- abstinent participants completed four conditions consisting of two ECIG-use bouts (10 puffs, 30 s interpuff-interval) differing only by liquid PG:VG ratio (2PG:98VG, 20PG:80VG, 55PG:45VG, 100PG). Device power (7.3 W) and liquid nicotine concentration (18 mg/ml) remained constant. Nicotine delivery, subjective effects, heart rate (HR), and puff topography were assessed.

RESULTS

In the 100PG condition, participants took shorter and smaller puffs but obtained significantly more nicotine relative to the two VG-based conditions. Total nicotine exposure (i.e., area under the curve) was also significantly higher during use of the two PG-based liquids. However, participants reported that the 100 PG liquid was significantly less "pleasant" and "satisfying" relative to the other liquids (all ps < .05). Increases in HR and decreases in abstinence symptoms (e.g., "craving") did not differ across conditions.

CONCLUSIONS

PG:VG ratio influenced nicotine delivery, some subjective effects, and puff topography. Lower overall product satisfaction associated with the 100PG liquid suggests factors other than nicotine delivery (e.g., aerosol visibility) may play a role in maintaining ECIG use. Regulating ECIG acute effects such as nicotine delivery and subjective effects may require simultaneous attention to liquid PG:VG ratio as well as device, liquid, and behavioral factors known to influence these outcomes.

Adolescents' understanding and use of nicotine in e-cigarettes

INTRODUCTION

Nicotine harms adolescent brain development and contributes to addiction. Some adolescents report using nicotine-free e-cigarettes, but the accuracy of their reporting is unclear. We explored adolescents' use of nicotine-free e-cigarettes and understanding of chemicals in e-cigarettes, including nicotine.

METHODS

Using social media, we recruited 1589 US adolescents (aged 15-17) who reported past 30-day use of e-cigarettes in 2016. We assessed perceptions of the nicotine source in e-liquid and whether e-cigarette aerosol is just "water vapor." We explored differences among adolescents who usually used e-cigarettes with nicotine (n = 473) and without nicotine (n = 452). We used weights to calibrate our sample to the Youth Risk Behavior Survey.

RESULTS

Twenty-nine percent usually used e-cigarettes without nicotine, 28% with nicotine, 39% with "both," and 5% were "not sure." Few participants (17% of non-nicotine users vs. 34% of nicotine users, p < .001) understood the nicotine was derived from tobacco. Youth who thought e-cigarette aerosol was just water vapor were more likely to usually use without nicotine. Older adolescents and current tobacco users were less likely to usually use without nicotine.

CONCLUSIONS

The adolescents who reported usually using e-cigarettes without nicotine had poorer knowledge of e-cigarettes. This lack of understanding could contribute to inaccurate reporting of nicotine use. Most youth thought the nicotine in e-cigarettes was artificial, potentially indicating a belief that this nicotine is "safer." The US Food & Drug Administration will require nicotine warnings on e-cigarettes in 2018; a complementary educational campaign could address youths' misperceptions about nicotine and other chemicals in e-cigarette aerosol.

Perceptions and Reasons Regarding E-Cigarette Use among Users and Non-Users: A Narrative Literature Review

This paper aims to provide an in-depth understanding of the attractiveness of e-cigarettes for several different groups. For this purpose, perceptions of and reasons for e-cigarette use were systematically reviewed as reported by e-cigarette users, cigarette smokers, dual users, and non-users, among both adults and youth. MEDLINE^&reg; and Scopus were used to search for relevant articles, and references of included studies were also investigated. Two reviewers screened all titles and abstracts independently, blinded to authors and journal titles (Cohen&rsquo;s Kappa = 0.83), resulting in 72 eligible articles. Risk perceptions, perceived benefits, and reasons for e-cigarette use were categorized in themes and sub-themes. Risk perceptions included harmfulness in general, and specific health risks. Perceived benefits included improved taste and smell, and safety for bystanders. Reasons for use included (health) benefits, curiosity, smoking cessation, and friends using e-cigarettes. The findings highlight that there is a variety of perceptions and reasons mentioned by adult and youth e-cigarette users, cigarette smokers, dual users, and non-users. As such, this overview provides valuable information for scientists, public health professionals, behavior change experts, and regulators to improve future research, risk communication, and possibilities to effectively regulate e-cigarettes.

Global Tobacco Use: Old and New Products

Tobacco use and exposure to tobacco smoke remain major but avoidable causes of premature mortality and disease worldwide. Although the age-standardized prevalence of daily smoking has declined for both men and women in many countries, the number of smokers continues to increase because of global population growth. Although cigarettes are the most commonly used tobacco product, the tobacco epidemic has become tremendously complex with the emergence and popularity of alternative products such as waterpipes and electronic cigarettes (also known as e-cigarettes). Exposure sciences play a major role in characterizing the tobacco epidemic as well as in the promotion, enactment, and implementation of tobacco control initiatives including legislation and voluntary measures in countries worldwide. We reviewed several studies in Latin America and other regions, showing how high-quality exposure assessment has contributed to smoke-free policies. Although there are many toxicants in tobacco products, metals could be playing an important role in tobacco-related disease. Tobacco plants accumulate cadmium and lead from soil. In e-cigarettes, a metallic coil heats the e-liquid to produce the aerosol that is inhaled by the vaper, and studies have found high aerosol levels of nickel, chromium, lead, and zinc. Despite many tobacco control successes, including the enactment of the Framework Convention on Tobacco Control, which has been ratified by 181 countries, tobacco control faces many challenges globally. Given the continuing increase in the number of smokers worldwide and the rapid emergence of new tobacco products, additional creative efforts are needed to achieve a smoke-free world, help smokers to quit, and protect youth from initiating tobacco use.

Establishing consensus on survey measures for electronic nicotine and non-nicotine delivery system use: Current challenges and considerations for researchers

The development and validation of survey measures for electronic nicotine and non-nicotine delivery system (ENDS) use has not kept pace with the burgeoning research on them. This, along with the diverse and evolving nature of ENDS, presents several unique measurement challenges and hampers surveillance and tobacco regulatory research efforts. In this commentary, we identify four important areas related to ENDS use (describing ENDS products; defining current use; evaluating frequency and quantity of use; and characterizing devices and e-liquids) and summarize a selective review of the measurement and definitions of these constructs across prominent national tobacco use surveys and 30 projects within the 14 federally-funded Tobacco Centers of Regulatory Science. Across these national, regional, and local studies, there was considerable variability and relatively little consensus in ENDS use measures - thus highlighting the need for caution when comparing findings across studies or over time until more research is available to evaluate the sensitivity of findings to differing measures. Drawing from the nascent ENDS use measurement research literature and our experiences, we conclude with general considerations for measuring ENDS use for tobacco researchers as an initial step towards the development of consensus measures.

Dual use of electronic nicotine delivery systems (ENDS) and smoked tobacco: a qualitative analysis

INTRODUCTION

Electronic nicotine delivery systems (ENDS) arguably pose fewer health risks than smoking, yet many smokers adopt ENDS without fully relinquishing smoking. Known as 'dual use', this practice is widespread and compromises the health benefits that ENDS may offer. To date, few studies have explored how dual use practices arise and manifest.

METHODS

We conducted in-depth, semi-structured interviews with 20 current ENDS users from New Zealand who reported smoking tobacco at least once a month. We explored participants' smoking history, their recent and current smoking, trial, uptake and patterns of ENDS use, and future smoking and vaping intentions. We managed the data using NVivo V.11 and used a thematic analysis approach to interpret the transcripts.

RESULTS

Dual use practices among participants evolved in four ways. First, as an attempt to manage the 'inauthenticity' of vaping relative to smoking and to retain meaningful rituals. Second, as complex rationalisations that framed decreased tobacco use, rather than smoking cessation, as 'success'. Third, as a means of alleviating the financial burden smoking imposed and to circumvent smoke-free policies. Lastly, dual use reflected attempts to comply with social group norms and manage stigma.

CONCLUSIONS

Dual use reflects both social and physical cues. It assisted participants to navigate smoking restrictions and allowed them to manage divergent norms. Policies that discourage smoking, particularly excise tax increases on smoked tobacco and smoke-free space restrictions, appear important in prompting ENDS use. Future research could explore whether these policies also help foster complete transition from smoking to exclusive ENDS use.

Associations of Electronic Cigarette Nicotine Concentration With Subsequent Cigarette Smoking and Vaping Levels in Adolescents

IMPORTANCE

Research indicates that electronic cigarette (e-cigarette) use (vaping) among adolescents is associated with the initiation and progression of combustible cigarette smoking. The reasons for this association are unknown.

OBJECTIVE

To evaluate whether use of e-cigarettes with higher nicotine concentrations is associated with subsequent increases in the frequency and intensity of combustible cigarette smoking and vaping.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective cohort study involving students from 10 high schools in the Los Angeles, California, metropolitan area, surveys were administered during 10th grade in the spring (baseline) and 11th grade in the fall (6-month follow-up) of 2015 to students who reported using e-cigarettes within the past 30 days and the nicotine concentration level they used at baseline.

EXPOSURES

Self-report of baseline e-cigarette nicotine concentration of none (0 mg/mL), low (1-5 mg/mL), medium (6-17 mg/mL), or high (≥18 mg/mL) typically used during the past 30 days.

MAIN OUTCOMES AND MEASURES

Frequency of combustible cigarette smoking and e-cigarette use within the past 30 days (0 days [none], 1-2 days [infrequent], or ≥3 days [frequent]) and daily intensity of smoking and vaping (number of cigarettes smoked per day, number of vaping episodes per day, and number of puffs per vaping episode) at the 6-month follow-up.

RESULTS

The analytic sample included 181 students (96 boys [53.0%] and 85 girls [47.0%]; mean [SD] age, 16.1 [0.4] years). Each successive increase in nicotine concentration (none to low, low to medium, and medium to high) vaped was associated with a 2.26 (95% CI, 1.28-3.98) increase in the odds of frequent (vs no) smoking and a 1.65 (95% CI, 1.09-2.51) increase in the odds of frequent (vs no) vaping at follow-up after adjustment for baseline frequency of smoking and vaping and other relevant covariates. Use of e-cigarettes with high (vs no) nicotine concentration was associated with a greater number of cigarettes smoked per day at follow-up (adjusted rate ratio [RR], 7.03; 95% CI, 6.11-7.95). An association with a significantly greater number of vaping episodes per day was found with use of low (adjusted RR, 3.32; 95% CI, 2.61-4.03), medium (adjusted RR, 3.32; 95% CI, 2.54-4.10), and high (adjusted RR, 2.44; 95% CI, 1.63-3.24) nicotine concentrations (vs no nicotine) at baseline. Similar results were found for the number of puffs per vaping episode for low (adjusted RR, 2.05; 95% CI, 1.41-2.70), medium (adjusted RR, 3.39; 95% CI, 2.66-4.11), and high (adjusted RR, 2.23; 95% CI, 1.42-3.03) nicotine concentrations.

CONCLUSIONS AND RELEVANCE

The results of this study provide preliminary evidence that use of e-cigarettes with higher nicotine concentrations by youths may increase subsequent frequency and intensity of smoking and vaping.

Relationship between spending on electronic cigarettes, 30-day use, and disease symptoms among current adult cigarette smokers in the U.S

OBJECTIVE

To examine the relationship between spending on electronic cigarettes (e-cigarettes) and disease symptoms compared with the relationship between 30-day e-cigarette use and disease symptoms among adult cigarette smokers in the U.S.

METHODS

We analyzed data from the Tobacco and Attitudes Beliefs Survey which included 533 respondents aged 24+ who were current cigarette smokers and e-cigarette ever users. Fifteen self-reported disease symptoms were included as outcome variables. Separate multivariable logistic regression models were estimated for each disease symptom with total spending on e-cigarettes in the past 30 days and with reported 30-day e-cigarette use. All models controlled for cigarettes smoked per day (CPD) and sociodemographic characteristics.

RESULTS

We found that those who spent more on e-cigarettes were more likely to report chest pain (AOR = 1.25, 95% CI 1.02-1.52), to notice blood when brushing their teeth (AOR = 1.23, 95% CI 1.02-1.49), to have sores or ulcers in their mouth (AOR = 1.36, 95% CI 1.08-1.72), and to have more than one cold (AOR = 1.36, 95% CI 1.05-1.78) than those with no spending on e-cigarettes in the past 30 days in an adjusted analysis. After controlling for CPD and other covariates, there were no significant relationships between 30-day e-cigarette use and symptoms. Even after controlling for CPD, e-cigarette expenditures or use was associated with greater odds of wheezing and shortness of breath.

CONCLUSIONS

E-cigarette expenditures might be a more useful measure of intensity of e-cigarette use. The additional health effect of e-cigarette use or expenditures among smokers independent of the effect of CPD suggests that e-cigarette use adds adverse health effects even among cigarette smokers.

"Essentially, All Models are Wrong, but Some Are Useful": A Preliminary Conceptual Model Of Co-Occurring E-Cig and Alcohol Use

PURPOSE OF REVIEW

As prevalence rates of electronic cigarette (e-cig) use increase, researchers and clinicians should not only be paying careful attention to the direct health effects of e-cigs, but also the potential impact e-cigs may have on alcohol use behaviors. We review the current state of the literature and propose a conceptual model for the relationship between e-cig and alcohol use, including important consequences, mechanisms, and moderators of this relationship.

RECENT FINDINGS

The model is based in emerging literature examining the direct relationship between e-cig and alcohol use, as well as indirect evidence concerning potential mechanisms from research on cigarette and alcohol use. Overall, research indicates a robust relationship between e-cig and alcohol use.

SUMMARY

We suggest that a relationship between e-cig use and alcohol use could be particularly problematic, especially for adolescents and for those with or at risk for alcohol use disorders. We hope the presented conceptual model can stimulate research in this area. We make research recommendations, including the need for more methodological rigor, including improved measurement of e-cig use, and expanding research to longitudinal and experimental designs.