Does Exposure to Electronic Nicotine Delivery Systems Advertising Affect Positive Smoking Expectancies and Social Normative Beliefs About Smoking?
Phase: NA
Conditions: Attentional Bias, Smoking Cues, Positive Perceptions About Cigarette Smoking, Social Norms, Smoking Susceptibility
Sponsor: Trustees of Dartmouth College

 
Title: Trial on the Effect of E-cigarette Advertising on Cigarette Perceptions in Adolescents 
 
NCT: NCT03786042 
 
Document date: Thursday December 12, 2024  
 
 
 
 

 
Research Approach  
 
We will achieve our aims by having 200 non-smoking adolescents (aged 15-16) complete a 
laboratory study (Figure 2). During their visit, Adolescents will then be randomly assigned to watch a 
smoking movie that manipulates exposure to ENDS Advertisements.  Attention to movie smoking will 
be measured using validated eye movement measures of attention.16 Adolescents will then complete 
SC-IAT task to measure how exposure to ENDS ads affected their implicit smoking expectancies and 
implicit normative beliefs.  
 
 
Priamry Measures  
 
Implicit measurement of positive smoking 
expectancies and social normative beliefs about 
smoking using the SC-IAT. A modified version of the 
SC-IAT15 will be administered before and after 
exposure to ENDS ads. The SC-IAT is a validated 
implicit association computer task that can be used to 
measure the associations between a visual cue (e.g., 
a smoking-related image) and a) personal implicit 
attitudes (e.g., implicit positive smoking expectancies) 
and b) implicit normative evaluations (e., social normative beliefs about smoking). The rationale for 
using the implicit association tests to assess implicit attitudes15 and implicit normative evaluations44 
have been described elsewhere. Adolescents will complete two phases, a personalized phase to 
measure their implicit positive smoking expectancies and a social phase to measure their implicit 
normative beliefs about smoking (Figure 3). Each trial in the personalized phase begins with the 
words “Things you find positive or negative …” presented in the upper middle of the screen that stays 
visible for the duration of the trial. After 500 msec, adolescents are presented with a visual smoking 
cue and associated word or short phrase presented in the middle of the screen. The word either 
conveys a positive smoking expectancy (e.g., relaxation) or a negative smoking expectancy (e.g., bad 
mood). The labels “Positive” and ‘Negative’ are presented on opposite sides at the top right-hand and 
left-hand side of the screen. The task of the participant is to categorize the cue word as “positive” or 
“negative” by pressing the spatially-mapped keyboard key as quickly and accurately as possible. The 
theory is that participants will categorize the word faster if the visual cue word pairing is congruent 
with their smoking expectancies. For example, an individual with high positive smoking expectancies 
would react faster if a visual smoking cue was paired with a positive word, such as “relaxation” than a 
negative word, such as “bad mood.” In a control condition, neutral non-smoking images are presented 
instead of smoking images. Trials in the social phase are like the personalized phase with the 
following expectations. Trials begin with the wording “Things most people find positive or negative 
…” followed by the presentation of the trial screen. The cue word will convey a positive (cool) or 
negative (uncool) social belief about smoking. Like above, the theory is that participants will 
categorize the word faster if the visual cue word pairing is congruent with their social normative 
beliefs about smoking. The order in which phases are completed will be counterbalanced, and 
experimental procedures will follow established methods.15 Visual smoking images and control 
images will be taken from the International Smoking Image database.49 Smoking-related images 
include photos of people smoking in a variety of environmental situations. Neutral images are 
identical but have the smoking cues removed. Positive and negative cue words will be sampled from 
previous research that have used similar tasks.50 and derived from scales that measure smoking 
expectancies51 and normative smoking beliefs17 designed for adolescents. 
 
ENDS ad and control exposure. Immediately following the first SC-IAT,   
Figure 3. SC-IAT Trial Types
Things you find positive 
or negative …”
POSITIVE
NEGATIVE
Good
mood
Things most people find 
positive or negative …”
POSITIVE
NEGATIVE
Being 
Popular
Personalized Trials: Positive  
smoking expectancies
Social Trials: Social Normative
beliefs 

 
adolescents will view a 15-minute movie clip that manipulates exposure to ENDS ads. ENDS ad 
exposure will be manipulated by embedding naturally occurring commercial breaks at 5 and 10 
minutes. During each break, adolescents in the ENDS ad exposure condition will view ENDS ads for 
30 seconds each. The commercial break will also include 3 30-sec control ads (e.g., food, clothes, 
and cars) to disguise the purpose of the experiment. Adolescents in the control ad condition will view 
4 minutes of control commercials at each break. Ends and control ads will be randomly sampled from 
the 8 most popular brands in the United States in 2016.  
 
Attention to dynamic smoking cues. Dynamic smoking cues are any action that promotes or 
represents a smoking behavior.53 Selective attention is an implicit measure of cue saliency that is 
defined as an automatic response to attend to an environmental stimulus.54 Measuring eye 
movements to dynamic cues has been shown to be a validated measure of selective attention to 
smoking cues in movies.42 Eye tracking will be recorded using the Gazepoint GP3 eye-tracker 
(Vancouver, British Columbia). The GP3 device has a sample rate of 60 Hz and an accuracy of 0.5 to 
1 degree of visual angle.  
 
Covariate Assessment. We will measure the following covariates because they have been 
associated them with tobacco advertising exposure and adolescent smoking, but are not thought to 
part of the causal pathway.18 We will collect sociodemographic factors including age, gender, and 
socioeconomic status. Socioeconomic status will be measured using the validated three item index of 
the Programme for International Student Assessment.18 We will also measure social influences on 
smoking using validated questions, including the smoking status of parents and the smoking status of 
peers.18 Rebelliousness and sensation seeking will be assessed using a validated 4-item index 
because it has been strongly associated with adolescent smoking intuition. Following our laboratory’s 
previous work, we will also measure long-term exposure to on screen movie smoking using a 
validated method.  
 
 
Primary analysis plan  
 
Our outcomes of interest are as follows: 1) Implicit positive vaping expectancy scores measured post-
intervention, and 2) selective attention to dynamic smoking cues. To assess the effect of ENDS 
advertising on implicit attitudes, we will use linear regression to predict Implicit positive vaping 
expectancy scores from advertising condition. We also use linear regression to assess the 
association between the amount of attention given to dynamic smoking cues and Implicit positive 
vaping expectancy scores. Specially, Implicit positive vaping expectancy scores will be predicted from 
dynamic attention scores in the onscreen smoking experimental arm.  For all analyses, we will first 
calculate appropriate summary statistics, assess normality, and transform the data if necessary. We 
will include potential covariates in all analyses when they are significantly associated with the 
outcome (P < 0.05). We will conduct all analyses in the full sample stratified by sex, and conduct 
formal tests for interactions using a Wald Test on sex by exposure multiplicative interaction terms in 
full models.