Brief Summary

The proposed study will conduct two randomized between-subject experiments among 6,000 adolescents (per each experiment) recruited nationwide to test the effects of audio-visual features of e-cigarette influencer marketing on perceptions of influencer credibility, e-cigarette harm perceptions, appeal, and susceptibility to e-cigarette use. This protocol represent the first experiment.

Trial Health

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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

6,000

participants targeted

Target at P75+ for not_applicable

Timeline

49mo left

Started Jan 2027

Longer than P75 for not_applicable

Geographic Reach

1 country

1 active site

Status

not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

4 years study duration

First Submitted

Initial submission to the registry

July 3, 2026

Completed

7 days until next milestone

First Posted

Study publicly available on registry

July 10, 2026

Completed

6 months until next milestone

Study Start

First participant enrolled

January 1, 2027

Expected

2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 30, 2028

2 years until next milestone

Study Completion

Last participant's last visit for all outcomes

December 30, 2030

Last Updated

July 20, 2026

Status Verified

July 1, 2026

Enrollment Period

2 years

First QC Date

July 3, 2026

Last Update Submit

July 17, 2026

Conditions

Vaping

Outcome Measures

Primary Outcomes (4)

Harm Perceptions of e-cigarettes
Responses to one question adapted from PATH, "Based on the videos you just watched, do you think using e-cigarettes for vaping nicotine is harmful to your health?" The outcome was assessed on the 5-point ordinal scale with the following response choices: Not at all harmful, slightly harmful, somewhat harmful, very harmful, extremely harmful.
Assessed 10 times immediately after each of the 10 videos during the 15-minute-long survey-based experiment
Perceived appeal of e-cigarettes
Responses to the following questions: using e-cigarette is: not cool/cool, unattractive/attractive were assessed on the 7-point semantic differential scale with the word pairs anchored at each end. The scale was adapted from prior research. The items were combined (by summing all the non-missing values of the items) into one variable (α=0.94).
Assessed 10 times immediately after each of the 10 videos during the 15-minute-long survey-based experiment
Susceptibility to e-cigarette use
Susceptibility to e-cigarette use was measured (among never-users of e-cigarettes), using the validated three-item scale (indicating peer influence, intention, and curiosity about e-cigarette use) adapted from PATH, and combined into one variable (α=0.93). Consistent with prior research, the measure was dichotomized with responses "definitely not" to all items being coded as "not susceptible" and responses "probably not," "probably yes", or "definitely yes" being coded as "susceptible.
Assessed 10 times immediately after each of the 10 videos during the 15-minute-long survey-based experiment
Perceived influencer credibility
Perceived influencer credibility (i.e., honesty, trustworthiness, knowledge) were assessed using a 0 (e.g., dishonest) -100 (e.g., honest) scale that has been validated in prior research.
Assessed 10 times immediately after each of the 10 videos during the 15-minute-long survey-based experiment