Identifying Effective Ads to Encourage Quitting Smoking Among People Who Smoke Menthol Cigarettes
Phase: NA
Conditions: Smoking Behaviors
Sponsor: UNC Lineberger Comprehensive Cancer Center

Protocol and statistical analysis plan  
 
Identifying effective ads to encourage quitting smoking among people who smoke menthol cigarettes 
 
NCT06485479 
 
8/13/2024 
 
 
 

2 
 
Protocol Synopsis  
 
Study Title 
Identifying effective ads to encourage quitting smoking among people who 
smoke menthol cigarettes 
Funder 
Food and Drug Administration (FDA) 
National Institute on Drug Abuse (NIDA) 
Clinical Phase 
N/A 
Study Rationale 
• 
Menthol cigarette use is an urgent public health problem and marked by 
stark disparities by race/ethnicity and sexual orientation.  
• 
This trial will identify ads that encourage quitting smoking among people 
who smoke menthol cigarettes. 
Study 
Objective(s) 
• 
To evaluate whether quit smoking ads elicit higher perceived message 
effectiveness than control messages.    
Study Design 
 
Randomized experiment 
Subject 
Population 
key criteria for 
and Exclusion: 
Inclusion Criteria 
• 
Currently smoke menthol cigarettes 
• 
Be a member of the AmeriSpeak online survey panel or their 
convenience sample 
• 
Live in the US 
• 
Be age 21 years or older 
• 
Read and speak English 
Exclusion Criteria 
1. Not currently smoke menthol cigarettes  
2. Not be a member of the AmeriSpeak online survey panel or their 
convenience sample 
3. Not live in the US 
4. Be younger than age 21 years  
5. Not be able to read and speak English 
 
Number of 
Subjects  
~1,400 
Study Duration 
Each subject’s participation will last approximately 15 minutes. 
The enrollment period is expected to last ~2-4 weeks. 
Study Phases 
  
There are two phases: 
(1) Screening: screening for eligibility and obtaining consent and  
(2) Intervention: study intervention/experimental treatment. 
Efficacy 
Evaluations 
The primary outcome is perceived message effectiveness for motivation of the 
ads at encouraging quitting smoking. It is measured with 1 survey item for each 
ad (6 items total). The secondary outcomes are perceived message 
effectiveness for response efficacy, perceived message effectiveness for self-
efficacy, intentions to quit smoking, response efficacy, and self-efficacy.   
Statistical and 
Analytic Plan 
• 
See page 3 of this document.  
Data and Safety 
Monitoring Plan 
• 
The principal investigators are responsible for data quality management 
and ongoing assessment of safety.   
 
 
 
 

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Study Protocol 
This trial will identify ads that encourage quitting among people who smoke menthol cigarettes by assigning 
them to 1 of 5 themes (3 intervention themes and 2 control themes). Each survey respondent will view 6 ads 
from one of the themes and respond to survey items about the ads. Thus, this is a 5 X 6 mixed-factorial design.  
 
Participants will be recruited through the AmeriSpeak online survey panel or their convenience sample. Survey 
respondents will complete an online randomized experiment programmed in Qualtrics. After providing informed 
consent, survey respondents will view and rate 6 ads, shown in a random order, on perceived message 
effectiveness (PME) for motivation (primary outcome), PME for response efficacy (secondary outcome), and 
PME for self-efficacy (secondary outcome). After viewing the ads, respondents will provide ratings of intentions 
to quit smoking (secondary outcome), response efficacy (secondary outcome), and self-efficacy of quit 
smoking (secondary outcome). Participants will receive incentives in an amount agreed upon with the panel 
company. 
 
We hypothesize that the intervention themes elicit higher PME scores than control themes. 
 
Statistical analysis plan 
To prepare for the analyses of the primary outcome, we will create a score for PME motivation by averaging 
responses to the 6 ads that each respondent views. If data are missing for one or more ads, we will take the 
average of the remaining responses. We will follow the same approach for the secondary outcomes.  
 
To compare the intervention and control themes, we will use linear regression with theme as a two-level 
predictor and PME motivation as a continuous outcome. Exploratory analyses will examine moderation by 
race, sexual orientation, and nicotine addiction, adding these as main effects and moderator variables to the 
analysis. To compare the three individual intervention themes, we will use linear regression, with dummy 
coding comparing one theme to the other two on PME motivation. To compare the two control themes, we will 
again use linear regression, using PME motivation as the outcome.  
 
We will also compare the themes on secondary outcomes using the same approach to compare intervention 
and control themes overall, and to look within intervention and control themes. Statistical analyses will use two-
tailed tests with a critical alpha of .05. Analyses comparing conditions will not use survey weights.