Considerations and Future Research Directions for E-Cigarette Warnings-Findings from Expert Interviews

Contingent Effects of E-Cigarette Warning Label Messages on Cognitive Elaboration and Fear Among U.S. Youth Ages 14-17 by Vaping Experience and Peer Vaping Behavior

The U.S. Food and Drug Administration (FDA) currently requires a warning about the addictive nature of nicotine to be placed on electronic cigarette advertisements and packaging. To consider the value of additional warning messages on public health outcomes, this study examines the additive effect of new warnings that are based on recent claims from U.S. federal authorities. We conducted a secondary analysis of recent data from 1,202 U.S. youth ages 14-17 to test the impact of exposure to additional warnings placed on advertisements for vaping products on cognitive elaboration, fear, and willingness to vape and smoke. This investigation also looked closely at effects on youth who may have increased risk of future vaping due to prior vaping experiences or having friends who vape. Exposure to the alternative warnings did not amplify cognitive elaboration compared to the current FDA warning alone, but it did increase fear. Youth elaboration on both the benefits and risks of vaping was associated with willingness to both vape and smoke, but fear was not associated with either outcome. The effects of warning label exposure and cognitive elaboration varied by prior vaping experience and having at least one friend who vapes. We conclude by discussing the implications of this contingent pattern of effect and association.

The Role of e-Cigarette Packaging as a Health Communications Tool: A Focus Group Study With Adolescents and Adults in England and Scotland

INTRODUCTION

In the United Kingdom, e-cigarette and refill packaging must display a nicotine addiction warning. This study explored how this message is perceived, responses to alternative on-pack messages, and other options for using e-cigarette packaging to discourage youth and people who neither smoke nor use e-cigarettes while encouraging smokers to switch.

AIMS AND METHODS

Between August and September 2022, 16 focus groups (n = 70) were conducted to explore these topics with adolescents (n = 31, aged 11-17 years) and adults (n = 39, nonsmokers, smokers that use e-cigarettes, smokers that do not use e-cigarettes) in England and Scotland.

RESULTS

While several participants thought the current nicotine addiction warning could help increase awareness of nicotine addiction, most reported that it failed to capture attention and was not a deterrent. Alternative messages shown on packs (about harm, toxicity, wellness, litter, or relative risk) received mixed responses. Relative risk messages were perceived as most beneficial for smokers switching but also thought to potentially encourage uptake among nonsmokers. Some participants considered certain harm and toxicity messages to potentially dissuade uptake. Participants proposed several ideas to reduce the appeal of e-cigarette packaging and devices to deter youth uptake, including more prominent warnings, standardized packaging, and devices that are plain or include health messages.

CONCLUSIONS

Packaging can play a crucial role in communicating product and health messages to different consumer groups. Further consideration of how packaging and labeling can meet the needs of non-nicotine users while simultaneously reaching those who may benefit from using e-cigarettes to stop smoking is warranted.

IMPLICATIONS

While some viewed the nicotine addiction warning required on e-cigarettes and refill packaging in the United Kingdom as helpful in raising awareness of nicotine addiction, it did not resonate with most of our sample of adolescents and adults. The findings suggest that e-cigarette packaging could be better used to encourage smokers to switch to a less harmful alternative, with relative risk messages showing promise. Furthermore, strengthening on-pack messaging (eg increasing salience and rotating messages) and reducing the appeal of packaging (eg drab colors) and devices (eg including warnings) may help increase awareness of e-cigarette harms while deterring use among adolescents and nonsmokers.

Youth and Young Adult-targeted E-cigarette Warnings and Advertising Messages: An Experiment with Young Adults in the US

Warnings specifically focused on harm to younger users have been understudied in vaping warning research, even while vaping products may appeal specifically to a younger population through implicit advertising strategies. This study examined how youth and young adult-focused e-cigarette health warning messages and implicit advertising strategies influence affective responses, risk perceptions, cognitive elaboration about e-cigarette harms, and willingness to vape in the future. We recruited young adults (who, at the time, were not smoking combustible cigarettes) aged 18-25 to participate in an online survey experiment with a 3 (warning label type: current FDA/youth and young adult risk-focused/none) × 3 (advertising health message strategy: explicit/implicit/none) + 3 (non-vaping products control) design. The results show a main effect for warning such that both FDA and targeted warnings increased negative affect and decreased positive affect compared to no warning. Moreover, the youth and young adult-focused warning boosted youth-specific harm beliefs and cognitive elaboration relative to control and the FDA warning, which did not differ from one another. Implicit health messages produced greater positive affect relative to explicit messages and no message, but the ad strategy manipulations did not influence other outcomes. While the population studied here with a single exposure reported no effects of either manipulation on willingness to vape, previous research has associated similar emotions and cognitions with lowered intentions to vape. Regulatory bodies should consider further exploration of vaping warnings that emphasize youth and young adult-specific harms to educate young people about relevant risks.

Changes in responses to nicotine vaping product warnings and leaflets in England compared with Canada, the US and Australia: findings from the 2016-2018 ITC Four Country Smoking and Vaping Surveys

BACKGROUND AND AIMS

In May 2017, black-and-white text nicotine addiction warning labels ('warnings') and health and safety leaflets ('leaflets') became mandatory for nicotine vaping products (NVPs) in England, in accordance with the European Union's Tobacco Products Directive. We compared changes over time in noticing warnings and leaflets, recall of warnings about nicotine and concerns about using NVP due to noticing warnings in England, compared with Canada, the US and Australia, where no warnings and leaflets were mandated.

DESIGN

19 005 adult (aged 18+) NVP users, smokers and quitters of cigarettes and NVP from the 2016 and 2018 International Tobacco Control Four Country Smoking and Vaping Surveys in England, Canada, the US and Australia, recruited via probability and non-probability sampling.

FINDINGS

Noticing warnings increased in England from 4.9% (2016) to 9.4% (2018) (adjusted OR/AOR=1.64, 95% CI=1.15-2.36); this change was larger than changes in Canada (AOR=2.51, 95% CI=1.71-3.69) and the US (AOR=2.22, 95% CI=1.45-3.39). Recall of a nicotine warning increased in England from 86% (2016) to 94.9% (2018) (AOR=5.50, 95% CI=1.57-19.27) but not significantly elsewhere. Noticing leaflets increased in England from 14.6% (2016) to 19.1% (2018) (AOR=1.42, 95% CI=1.15-1.74); this change was larger than in Canada (AOR=1.42, 95% CI=1.12-1.79), the US (AOR=1.55, 95% CI=1.17-2.06) and Australia (AOR=1.51, 95% CI=1.02-2.22). Among those noticing warnings, concern about NVP use did not change significantly between 2016 and 2018 (all countries p>0.081).

CONCLUSIONS

Introduction of mandatory NVP warnings and leaflets in England was associated with small increases in noticing them but not with changes in concerns about NVP use.

Does warning language impact perceptions? Results from an exploratory experiment comparing English, Spanish, and Dual language E-Cigarette warnings among Spanish speakers in the US

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We explored the impact of English only, Spanish only, or dual language warnings.

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Dual language exposure increased affect, reactance, and message effectiveness.

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Warning language may impact warning effectiveness among Spanish speakers.

Tobacco warnings written in English may not be as effective among Spanish speakers. We explored whether warning perceptions differ based on exposure to English, Spanish, or dual language warnings. From November 2, 2020 – December 29, 2020, we conducted an online experiment with a convenience sample of 776 Spanish-speaking adults in the US, randomizing each to one of three warning conditions: English only, Spanish only, or dual (both English and Spanish). Multivariable linear and logistic regressions examined associations between warning exposure and perceptions. Of 776 participants, 291 preferred to read in Spanish, 55.5% were male, 62.5% were Hispanic, and 48.1% reported past 30-day e-cigarette use. Negative affect (β = 1.79, p = 0.007), perceived message effectiveness (β = 0.84, p = 0.007), and psychological reactance (β = 1.55, p < 0.001) were greater among participants exposed to the dual language warnings compared to those exposed to the English warnings. Results of this exploratory study suggest that e-cigarette warning statements presented in both English and Spanish may result in stronger reactions among Spanish speakers. With increasing prevalence of Spanish speakers in the US, future work should continue to examine this topic.

Does the content and source credibility of health and risk messages related to nicotine vaping products have an impact on harm perception and behavioural intentions? A systematic review

AIMS

To systematically review the literature on (i) whether and how various risk messages about nicotine vaping products (NVPs) alter harm perception and behavioural intentions of smokers and non-smokers and (ii) how trust in sources of NVP risk communication affects message reception and behavioural intentions.

METHODS

Seven electronic databases and reference lists of relevant articles were searched for articles published up to April 2020. Experimental and quasi-experimental studies on message effects and cross-sectional studies on source credibility were included. The Newcastle-Ottawa Scale and the Evidence Project Risk of Bias Tool were used to assess the quality of observational and intervention studies, respectively. For each outcome variable, we indicated whether there was an effect (as a 'yes' or 'no') and used effect direction plots to display information on the direction of effects.

RESULTS

Nicotine addiction messages resulted in greater health and addiction risk perceptions, relative risk messages comparing the health risks of NVPs to cigarette smoking increased the perception that NVPs are less harmful than combustible cigarettes, and a nicotine fact sheet corrected misperceptions of nicotine and NVPs. Smokers' intention to purchase, try or switch to NVPs was higher when exposed to a relative risk message and lower when exposed to nicotine addiction warnings. Trust in NVP risk information from public health agencies was associated with lower odds of; (i) NVP use and (ii) perceiving NVPs as less harmful, whereas those who trusted information from NVP companies were more likely to perceive NVPs as less harmful than combustible cigarettes.

CONCLUSIONS

Relative risk messages may help improve the accuracy of harm perceptions of nicotine vaping products and increase smokers' intentions to quit smoking and/or to switch to vaping, although the literature is nascent.

Effective package warning label systems for communicating relative risks of cigarettes, heated tobacco products, and e-cigarettes: An experimental study with Korean adults

BACKGROUND

Warning labels are a fundamental public health strategy for communicating about tobacco product risks, but effective warning labels for heated tobacco products (HTPs) and e-cigarettes (ECs) are yet to be determined. We examined the effect of two warning label systems for communicating the relative risks of using cigarettes, HTPs, and ECs.

METHODS

1,280 Korean adults were recruited from an online commercial panel, including susceptible non-users of cigarettes, HTPs, or ECs aged 19 to 29 (n = 444) and current users of these tobacco products aged 19 or older (n = 836). Participants viewed packages for cigarettes, HTPs, and ECs in a 2 × 2 between-subject experiment: "dashboard" icons integrated into warnings vs. no dashboard; different-sized warnings (70% of cigarette packages, 50% of HTP packs, 30% of EC packages) vs. current equal-sized warnings (50% of cigarette/HTP/EC packages).

RESULTS

Participants exposed to the dashboard warning system were more likely than those who were not to report higher perceived harm of cigarettes than ECs, cigarettes than HTPs, and HTPs than ECs, as well as perceived benefit of switching from cigarettes to HTPs, cigarettes to ECs, and HTPs to ECs. Participants exposed to the different-sized warning system did not report differences in perceived relative harm or benefit compared to those who were not, and no interaction of dashboard warnings with warning sizes was found.

CONCLUSION

The use of dashboard icons with texts and colors representing different levels of risk may promote public understanding about the continuum of risk across tobacco products.

Development and testing of relative risk-based health messages for electronic cigarette products

BACKGROUND

Health messages on e-cigarette packs emphasise nicotine addiction or harms using similar wording to warnings on cigarette packs. These may not be appropriate for e-cigarettes which constitute a reduced risk alternative for smokers. This research aimed to (1) develop and test a selection of relative risk messages for e-cigarette products; (2) compare these to the two current EU Tobacco Products Directive (TPD) nicotine addiction messages; and (3) explore differences between smokers, non-smokers and dual users.

METHOD

Twenty-six messages focusing on either harm-reduction or cessation were developed and rated by multidisciplinary experts for accuracy, persuasiveness and clarity. The eight highest ranking messages were compared alongside the TPD messages in a sample of 983 European residents (316 smokers, 327 non-smokers, 340 dual users) on understandability, believability and convincingness.

RESULTS

On all three constructs combined, the two TPD messages rated the highest, closely followed by four relative risk messages "Completely switching to e-cigarettes lowers your risk of smoking related diseases", "Use of this product is much less harmful than smoking", "Completely switching to e-cigarettes is a healthier alternative to smoking", and "This product presents substantially lower risks to health than cigarettes" which did not differ statistically from the TPD messages. Non-smokers rated TPD1 significantly higher overall than dual users. Dual users rated "This product is a safer alternative to smoking" significantly higher than non-smokers. Messages did not differ on understandability.

CONCLUSIONS

These alternative messages provide a useful resource for future research and for policy makers considering updating e-cigarette product labelling.

Analysis of on-pack messages for e-liquids: a discrete choice study

BACKGROUND

Policymakers wishing to encourage smokers unable to quit to switch to using electronic nicotine delivery systems (ENDS) also need to consider how to deter ENDS use among non-smokers. We examined whether reduced-risk messages could increase ENDS' appeal among smokers and if increased-risk messages could decrease appeal among susceptible non-smokers, occasional and former smokers.

METHODOLOGY

An online discrete choice experiment tested three attributes: information message, nicotine content (0 mg or 3 mg) and flavour (tobacco, menthol or fruit). The sample comprised 352 current smokers, 118 occasional and former smokers, and 216 ENDS-susceptible never smokers. Smokers viewed reduced-risk messages that encouraged switching to ENDS, while other groups viewed increased-risk messages that discouraged ENDS use. All groups saw a typical addiction warning. We analysed the data by estimating multinomial logit regression and adjusted latent class analysis models.

RESULTS

Relative to no message, reduced risk-messages increased the appeal of ENDS uptake among one class of smokers (33.5%) but decreased appeal among other smokers. However, among all smokers, reduced-risk messages increased preference more than a dissuasive addiction warning. By contrast, among occasional or former smokers, and susceptible non-smokers, all information messages discouraging ENDS use, including an addiction warning, decreased preference relative to no message.

CONCLUSIONS

On-pack relative-risk messages about ENDS could make transition more attractive to smokers while increased-risk messages could deter ENDS uptake among susceptible non-smokers, occasional and former smokers. Communicating diverse messages via discrete channels could recognise heterogeneity among and between smokers and non-smokers.

Reactions to messages about smoking, vaping and COVID-19: two national experiments

Introduction

The pace and scale of the COVID-19 pandemic, coupled with ongoing efforts by health agencies to communicate harms, have created a pressing need for data to inform messaging about smoking, vaping, and COVID-19. We examined reactions to COVID-19 and traditional health harms messages discouraging smoking and vaping.

Methods

Participants were a national convenience sample of 810 US adults recruited online in May 2020. All participated in a smoking message experiment and a vaping message experiment, presented in a random order. In each experiment, participants viewed one message formatted as a Twitter post. The experiments adopted a 3 (traditional health harms of smoking or vaping: three harms, one harm, absent) × 2 (COVID-19 harms: one harm, absent) between-subjects design. Outcomes included perceived message effectiveness (primary) and constructs from the Tobacco Warnings Model (secondary: attention, negative affect, cognitive elaboration, social interactions).

Results

Smoking messages with traditional or COVID-19 harms elicited higher perceived effectiveness for discouraging smoking than control messages without these harms (all p <0.001). However, including both traditional and COVID-19 harms in smoking messages had no benefit beyond including either alone. Smoking messages affected Tobacco Warnings Model constructs and did not elicit more reactance than control messages. Smoking messages also elicited higher perceived effectiveness for discouraging vaping. Including traditional harms in messages about vaping elicited higher perceived effectiveness for discouraging vaping (p <0.05), but including COVID-19 harms did not.

Conclusions

Messages linking smoking with COVID-19 may hold promise for discouraging smoking and may have the added benefit of also discouraging vaping.

Compliance With FDA Nicotine Warning Statement Provisions in E-liquid Promotion Posts on Instagram

INTRODUCTION

Effective August 2018, the U.S. Food and Drug Administration (FDA) required that nicotine addiction warnings be placed on ads for nicotine containing e-liquids. As per FDA comments, this provision pertains to visual ads communicated via social media, raising questions about compliance within the large e-liquid promotion community on Instagram.

AIMS AND METHODS

This study examines use of warnings on promotional Instagram posts before and after provisions took effect on August 10, 2018. Netlytic was used to gather a sample of 500 promotional #eliquid and #ejuice posts from: May 2017, October 2017, March 2018, August 2018, and September 2018. The 1500 prewarning and 1000 postwarning posts were coded using content analysis. Changes in products and marketing strategies were also considered. Post volume was tracked monthly between May 2017 and February 2020.

RESULTS

In the prewarning period, nicotine warning statements were absent on all posts. Following August 10, 2018, FDA compliant warnings were present on 13.6% of posts. Among US-based posts, 36.4% used the warnings, with warnings more common on posts made by e-liquid brands (52.3%) and posts promoting e-liquids with nicotine (40.0%). Promotional strategies and products did not significantly change. The share of posts made by US Instagram users decreased by 11%, although total post volume continued to grow.

CONCLUSIONS

Many e-liquid promotion posts on Instagram remained noncompliant with nicotine warnings after FDA provisions took effect. The large volume of international users also limited the impact of FDA-mandated warnings on the social media environment.

IMPLICATIONS

Further guidance and enforcement are needed to ensure that US e-liquid marketers on visual social media platforms adhere to current provisions, particularly for individual social media users who are sponsored by industry. The inherently global span of social media also indicates the importance of a shared approach to marketing regulations. Further work is needed to assess enforcement strategies viable for the social media environment.

Baseline assessment of noticing e-cigarette health warnings among youth and young adults in the United States, Canada and England, and associations with harm perceptions, nicotine awareness and warning recall

Health warnings on tobacco products can inform users of potential risks. However, little is known about young people's exposure to health warnings on e-cigarette products. This baseline assessment of young people's noticing e-cigarette warnings uses nationally representative data from three countries.

Data were collected under Wave 1 of the ITC Youth Tobacco and E-cigarette Survey, conducted in Canada, England, and the US. Online surveys were completed by 16–19-year-olds in July/August 2017 (n = 12,064), when warnings were either newly required (England) or voluntarily carried by some manufacturers (US, Canada). Analyses examined prevalence and correlates of noticing warnings and associations between noticing warnings and product perceptions, adjusting for country, sex, age, race/ethnicity, and cigarette/e-cigarette use status.

About 12% reported noticing warnings on e-cigarette packaging in the past 30 days. Noticing warnings was significantly more likely among youth in England (AOR = 1.3, p < .01) and the US (AOR = 1.3, p < .01) versus Canada, and was most likely among dual e-cigarette/cigarette users (AOR = 4.69, p < .001) versus nonusers. Unaided recall of the keyword “nicotine” was low among those who noticed warnings (7.5%). However, ever e-cigarette users who noticed warnings had higher odds of knowing whether e-cigarettes contained nicotine (AOR = 2.26, p < .001). Noticing warnings was significantly associated with higher odds of believing e-cigarettes cause at least some harm to users (AOR = 1.19), are as harmful as cigarettes (AOR = 1.45), and can be addictive (AOR = 1.43).

Baseline assessment reveals that youth's noticing of e-cigarette warnings and recall of nicotine-addiction messages was low. Research should track exposure over time as warning requirements are implemented across different countries.

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Noticing warnings on e-cig products is low in the US, England and Canada.

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Ever users: noticing warnings had higher odds of not knowing e-cigs have nicotine.

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Noticing warnings associated with higher odds of believing e-cigs can be addictive

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Exposure should be tracked over time as warnings are implemented across countries.

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Exposure to e-cig warnings may influence harm perceptions and use intentions.

Impact of e-cigarette health warnings on motivation to vape and smoke

BACKGROUND

A prevailing hypothesis is that health warnings for electronic cigarettes (e-cigarettes) could drive people away from vaping and towards smoking cigarettes. We consider an alternative hypothesis that e-cigarette warnings discourage both vaping and smoking.

METHODS

Participants were a national convenience sample of 2218 US adults who used e-cigarettes, cigarettes or both. In August 2018, we randomised participants to one of three warning types (control text about littering, text-only e-cigarette warning or pictorial e-cigarette warning). We further randomised participants viewing e-cigarette warnings to one of three topics (nicotine addiction, health hazards of use, or both health hazards and harms of use). The preregistered primary outcome was intentions to quit vaping among e-cigarette users. Secondary outcomes included interest in smoking and Tobacco Warnings Model constructs: attention, negative affect, anticipated social interactions and cognitive elaboration.

RESULTS

Text warnings elicited higher intentions to quit vaping than control among e-cigarette users (d=0.44, p<0.001), and pictorial warnings elicited still higher intentions to quit vaping than text (d=0.12, p<0.05). Text warnings elicited lower interest in smoking compared with control among smokers (p<0.05); warnings had no other effects on interest in smoking among smokers or non-smokers. Text warnings about health hazards elicited higher intentions to quit vaping than nicotine addiction warnings. E-cigarette warnings also increased Tobacco Warnings Model constructs.

DISCUSSION

E-cigarette health warnings may motivate users to quit vaping and discourage smoking. The most promising warnings include health hazards (other than nicotine addiction) and imagery. We found no support for the hypothesis that e-cigarette warnings could encourage smoking cigarettes.

US young adults' perceived effectiveness of draft pictorial e-cigarette warning labels

SIGNIFICANCE

Research shows that pictorial warning labels for cigarettes are more effective than text-only warnings, and preliminary work suggests that pictorial warnings could also be considered for electronic cigarettes (e-cigarettes). Pictorial warnings may be important for maximising their effectiveness among young people and enhancing the salience of the single nicotine addiction warning required for e-cigarettes to date in the USA. This study collected pilot data about the perceived effectiveness of draft e-cigarette pictorial warnings.

METHODS

Participants were 876 young adults (ages 18-29) recruited through Amazon Mechanical Turk who completed an online e-cigarette survey in 2018. Participants viewed and ranked five versions of the same e-cigarette nicotine addiction warning message-four pictorial and one text-only-on their perceived noticeability, likelihood of capturing young people's attention, memorability, relevance to the addiction warning text and overall effectiveness in warning people about e-cigarette risks. For each outcome, presentation of the five warning versions was randomised. Pictorials included symbolic images of risk and addiction, and of priority audiences for the warning (ie, young people).

RESULTS

For all outcomes, pictorial warnings were ranked higher than the text-only warning, and the warning using a yellow triangle caution icon was ranked highest for all outcomes. The text-only warning was ranked as the least likely to be effective for all four outcomes in which it was assessed. Trends were similar for current e-cigarette users and non-users.

CONCLUSIONS

Future research should assess perceptions and the appropriateness of pictorial imagery for e-cigarette warnings and test their efficacy against text-only warnings experimentally.

The Impact of E-Cigarette Warnings, Warning Themes and Inclusion of Relative Harm Statements on Young Adults' E-Cigarette Perceptions and Use Intentions

Although e-cigarettes in the United States are required to carry one nicotine addiction warning, little is known about the impact of other potential e-cigarette warning themes, nor about pairing warnings with messages that communicate e-cigarettes' reduced-harm potential relative to cigarettes. We randomly assigned 876 young adults (ages 18⁻29) to view e-cigarette ads in a 3 × 2 plus control online experiment that varied by warning theme (i.e., nicotine addiction; nicotine's impact on adolescent brain development; presence of harmful chemicals) and warning type-i.e., the presence ("relative harm warning") or absence ("standard warning") of a relative harm (RH) statement in the warning label ("e-cigarettes may cause harm to health but are less harmful than cigarettes"). Warning believability, informativeness, understandability and support were high across conditions and there were no significant differences by warning theme on e-cigarette harm perceptions or use intentions nor on nicotine (mis)perceptions. Perceived warning effectiveness for discouraging youth initiation was higher for the "brain" and "chemicals" warnings compared to the addiction warning. Warnings with the included RH statement were perceived as less believable and credible and were less frequently correctly recalled. Research should continue to investigate the impact of different e-cigarette warning themes and formats with priority audiences.

The effects of the European e-cigarette health warnings and comparative health messages on non-smokers' and smokers' risk perceptions and behavioural intentions

BACKGROUND

Article 20 of the EU Tobacco Products Directive [TPD] stipulates that e-cigarette packets and refill products must carry a nicotine addiction health warning. Although previous studies conducted in North America have found that perceived harm, addictiveness and intention to use declined following exposure to e-cigarette health warnings, possible effects of the TPD health warnings on smokers and non-smokers has not been studied. This study will investigate the effects of the EU TPD e-cigarette health warnings and a comparative harm message (COMP; developed specifically for this study) on smokers' and non-smokers' perceptions of harm, addictiveness and social acceptability of e-cigarettes. Additionally, the potential effects of the TPD warnings and the COMP on smokers' intentions to purchase and use e-cigarettes will be explored.

METHODS/DESIGN

A sample of 2400 UK residents will be recruited in this experimental, randomised design, with Smoking status (Smoker vs. Non-smoker), TPD presence (TPD1 vs. TPD2 vs. No-TPD) and COMP presence (Presence vs. Absence) as between subjects independent variables, and Time (pre-post exposure of images) as a within subjects factor. Dependent variables comprise self-reported perceived harm, addictiveness, social acceptability, e-cigarettes' effectiveness, intentions to purchase and use e-cigarettes. Cigarette dependence, previous e-cigarette exposure, and baseline intentions to quit will be measured as covariates.

DISCUSSION

Health warnings, such as those implemented by the TPD, may help to prevent non-smokers from e-cigarettes use, but it is possible that they may inadvertently deter smokers from initiating use and substituting their tobacco smoking for e-cigarettes use if their content is deemed too negative. It is hoped that this study will help identify the most effective message or combination of messages that encourage use among smokers without promoting use among non-smokers.

TRIAL REGISTRATION

ISRCTN registry ISRCTN76967031 ; date of registration: 23/10/18.

Placing Health Warnings on E-Cigarettes: A Standardized Protocol

Health warnings for e-cigarettes are a promising and novel tobacco control intervention for reducing e-cigarette use. We developed a new protocol for evaluating e-cigarette warnings by placing them on users' own devices to reflect real-world exposure. Study 1 participants were a national convenience sample of 606 U.S. adult e-cigarette users surveyed online in March 2017. Most Study 1 participants were willing to have their e-cigarette devices (87%) and refills (83%) labeled. Study 2 participants were a convenience sample of 22 adult e-cigarette users recruited in California, United States in April 2017. We applied the U.S. Food and Drug Administration's proposed e-cigarette warning to users' own devices and refills. Most Study 2 participants (81%) reported using e-cigarette devices with our warning labels at least 90% of the time during the study. Nearly all (95%) said they would participate in the study again, and 100% would recommend the study to a friend. Conversations about e-cigarette harms, conversations about quitting e-cigarettes, and intentions to quit using e-cigarettes increased during the study (all p < 0.05). These studies show that our naturalistic labeling protocol was feasible, acceptable to participants, and had high retention over three weeks. Using the protocol can yield important evidence on the impact of e-cigarette warnings to inform tobacco warning policies.

The Association between Potential Exposure to Magazine Ads with Voluntary Health Warnings and the Perceived Harmfulness of Electronic Nicotine Delivery Systems (ENDS)

(1) Background: Several brands of electronic nicotine delivery systems (ENDS) carry voluntary health warning messages. This study examined how potential exposure to ENDS magazine ads with these voluntary health warnings were associated with the perceived harmfulness of ENDS. (2) Methods: Risk perception measures and self-reported exposure to ENDS ads were obtained from the 2014 Georgia State University (GSU) Tobacco Products and Risk Perceptions Survey of a nationally representative sample of U.S. adults. We examined the association between potential exposure to magazine ads with warnings and the perceived harms of ENDS relative to cigarettes, using binary logistic regressions and controlling for general ENDS ad exposure and socio-demographic characteristics. (3) Results: Potential exposure to ENDS magazine ads with warnings was associated with a lower probability of considering ENDS to be more or equally harmful compared to cigarettes, particularly among non-smokers (OR = 0.16; 95% CI: 0.04–0.77). In addition, ad exposure, ENDS use history, race/ethnicity, gender, education, and income were also associated with harm perceptions. (4) Conclusions: This study did not find evidence that magazine ads with warnings increased misperceptions that ENDS are equally or more harmful than cigarettes. With more ENDS advertisements carrying warnings, more research is needed to determine how the warnings in advertisements convey relative harm information to consumers and the public.

The impact of flavour, device type and warning messages on youth preferences for electronic nicotine delivery systems: evidence from an online discrete choice experiment

OBJECTIVE

To examine the impact of flavour, device type and health warning messages on youth preference for electronic nicotine delivery systems (ENDS), and to provide evidence and data to inform the Food and Drug Administration's potential regulatory actions on ENDS.

DESIGN

An online discrete choice experiment was conducted in September 2015. Each participant was given nine choice sets and asked to choose one out of two alternative ENDS products, with varying characteristics in three attributes (flavour, device type and warning message). The impact of the attributes on the probability of choosing ENDS was analysed using conditional and nested logit regressions, controlling for individual sociodemographic characteristics and current smoking status.

SETTING AND PARTICIPANTS

A general population sample of 515 participants (50 ever-users and 465 never-users of ENDS) aged 14-17 years were recruited to complete the experiment using an online panel.

RESULTS

Fruit/sweets/beverage flavours significantly increase the probability of choosing ENDS among youth (p<0.01 for never-users and <0.1 for ever-users) and flavour has the most pronounced impact among three attributes. Among never-users, menthol flavour also increases (p<0.05) the probability of choosing ENDS compared with tobacco flavour. Vaping devices that are modifiable, compared with cigarette-like e-cigarettes, increase (p<0.05) the probability of choosing ENDS among adolescent never-users. Warning messages reduce (p<0.01) the probability of choosing ENDS among never-users.

CONCLUSIONS AND RELEVANCE

Restricting fruit/sweets/beverage flavours in ENDS, regulating modifiable vaping devices and adopting strong health warning messages may reduce the uptake of ENDS among youth.