Impact of The Real Cost Vaping Prevention Advertisements on Adolescents
Phase: NA
Conditions: Vaping
Sponsor: UNC Lineberger Comprehensive Cancer Center

 
 
 
 
 
 
 
 
 
 
 
Impact of The Real Cost Vaping Prevention Advertisements on Adolescents 
Protocol
NCT #04836455
Version Date: 5/27/2021

Participants 
 
We recruited adolescents living in the United States (US) from online panels 
administered by Qualtrics. Eligibility criteria were: aged 13 through 17 years, able to read and 
speak in English, able to take an online survey in English, and susceptible to e-cigarette use as 
shown by an answer of 2 or greater on any of five e-cigarette susceptibility items.24 The 
susceptibility items assessed the extent to which adolescents were open to vaping, with a 4-point 
response scale that ranged from “definitely not” (coded as 1) to “definitely yes” (4).  
 
Our target sample size was 1,500, which accounted for up to 33% of participants 
dropping out during the trial. With an estimated intraclass correlation of .70, the trial had power 
to detect an effect size of d=.25 or larger between intervention arms (combined) and the control 
arm.12  
 
Recruitment took place from September to November 2021. Legal parents or guardians 
provided informed parental consent online, and adolescents provided assent online before 
beginning the surveys. Of the 1,708 adolescents who met inclusion criteria, 151 declined to 
participate and 43 were screened but unable to enroll because the study quota had been met 
(Figure 1). This trial was approved by the University of North Carolina Institutional Review 
Board and is registered at clinicaltrials.gov, identifier NCT04836455 
(https://www.clinicaltrials.gov/ct2/show/NCT04836455). This paper follows CONSORT 
reporting guidelines for RCTs.25 
Procedures 
Trial design and protocol. We conducted a three-arm RCT with parallel assignment. 
Adolescents participated in four weekly online visits over a three-week period, completing a 
survey at each visit. Exposures to campaign ads occurred at Visits 1, 2, and 3. At the start of the 

trial (Visit 1), participants were randomized to see a series of ads from one of two FDA Real 
Cost vaping prevention ad trial arms (health harms or addiction) or to a control arm 
(investigator-created neutral videos about vaping). Qualtrics software used simple randomization 
based on a single allocation ratio. Participants were randomized without replacement to one of 
the three trial arms using the Qualtrics randomizer. In each trial arm, participants viewed the 
same three ads per session, in a random order, corresponding to the trial arm they were assigned. 
Participants were told they were going to view three short ads, but received no information on 
the content or number of arms. The research team was not blinded after assignment because 
interventions were administered online.  
At each of the visits (Visits 1 – 4), participants completed surveys reporting primary and 
secondary outcomes. Participants received incentives in the form of points for taking the surveys, 
with a total cash equivalent of $35 after completing the trial ($5 for the first and second surveys, 
$10 for the third survey, and $15 for the final survey). A pilot study with 51 participants was 
conducted prior to the trial to test trial procedures.   
Intervention messages. Participants in both intervention trial arms viewed three 30-
second ads from the Real Cost campaign, corresponding to one of the two major themes of the 
campaign. Those in the health harms trial arm viewed ads about toxic substances and lung 
damage, while those in the addiction trial arm viewed ads about consequences of nicotine 
addiction. Those in the control arm viewed three 30-second investigator-created neutral videos 
about vaping consisting of black text on a white screen with a narrator reading the text. The 
content of these ads included product definitions, farming practices, and manufacturing practices 
adapted from Wikipedia and other sources (see the Table 1). 
 

Measures 
At the first session (Visit 1), each participant reported vaping and smoking behaviors in 
the survey, then viewed ads that corresponded to their trial arm. They completed measures 
assessing message reactions after viewing each ad, after which they completed measures of 
susceptibility to vaping and smoking, vaping and smoking beliefs, and demographics. For the 
subsequent weeks of the trial (Visits 2 and 3), participants completed surveys with measures of 
susceptibility to vaping and smoking, vaping and smoking beliefs, and vaping and smoking 
behavior. Then, they viewed the same three ads from their trial arm and completed the message 
reactions items. At Visit 4, participants completed surveys assessing susceptibility to vaping and 
smoking, vaping and smoking beliefs, and vaping and smoking behavior (eFigure 1 in the 
Supplement). 
Primary outcome. Susceptibility to vaping at Visit 4 was the primary trial outcome. 
Susceptibility prospectively predicts vaping behavior,26,27 including as a scaled score where 
higher values predict both greater initiation and current use of vapes.27 We assessed 
susceptibility with a 3-item susceptibility to vaping scale, similar to other studies.28-31 This scale 
assesses the extent to which adolescents are open to vaping, with a 4-point response scale 
ranging from “definitely not” (coded as 1) to “definitely yes” (coded as 4) (eTables 2 and 3 in the 
Supplement). We calculated a susceptibility score by averaging the 3 items, with higher scores 
representing higher susceptibility (Cronbach’s α=.93). Susceptibility was measured after ad 
exposure at Visit 1 to capture immediate ad impact and before ad exposure at Visits 2-4 to 
capture ad impact over time. 
Secondary outcomes. The survey assessed several secondary outcomes hypothesized to 
elicit behavior change. Response scales for most secondary outcomes had five points, coded such 

that higher scores represented a greater amount of the construct. For multi-item scales, overall 
scale scores were of the average of the items.  
Message reactions. A single item assessed attention to the message32 and a 3-item scale 
assessed negative affect (α=.83).32 Message reactions were measured immediately following ad 
exposure. These measures were last assessed at Visit 3 because the ads were not shown at Visit 
4.  
Vaping outcomes. Three-item scales assessed cognitive elaboration (α=.92),33 social 
interactions (α=.94),34 vaping health harm risk beliefs (α=.92),35 vaping addiction risk beliefs 
(α=.89),35 and vaping attitudes (α=.91).36 Participants reported the number of days they vaped 
over the past 7 days at each visit. These outcomes were measured after ad exposure at Visit 1 
and before ad exposure at Visits 2-4, except for days vaped which was always measured before 
ad exposure. 
Smoking outcomes. Single items assessed smoking health harm risk belief, addiction risk 
belief, and smoking attitude. Susceptibility to smoking was assessed with a 3-item scale (α=.95). 
Participants reported the number of days they smoked over the past 7 days at each visit. We 
chose to retain the continuous measures of number of days vaping and smoking rather than 
dichotomizing these outcomes (as proposed in our trial registration) because we found 
substantial variability in number of days that these products were used.  
 
 
 
 
 

 
Table 1. Vaping Prevention Video Ads used in the Trial 
Condition 
Ads 
Prior recall n(%) 
Real Cost –
Health Harms 
Epidemic: https://vimeo.com/325055700 
Facts of Vaping: https://vimeo.com/413710792 
Toxic Metals: https://vimeo.com/413711298 
198 (39.3%) 
189 (37.5%) 
185 (36.7%) 
Real Cost –
Addiction 
Hacked: https://vimeo.com/325055712 
Vaping Mistake – Danny: https://vimeo.com/413711020 
Nicotine addiction isn't pretty – Bathroom:https://vimeo.com/520033399 
191 (37.7%) 
186 (36.8%) 
187 (37%) 
Control 
Definition: https://vimeo.com/514315064 
Farming: https://vimeo.com/514315483 
Manufacturing: https://vimeo.com/514315497 
n/a 
Note. Prior recall refers to reporting in the Visit 1 survey that participants had seen one or more of the ads in their 
assigned trial arm previously.