Trial Outcomes & Findings for Impact of E-cigarette Device Warnings (NCT NCT05714982)

Results Overview

The primary outcome is vaping quit intentions measured by 3 survey items at 5 time points: post-labeling (Visit 1) and at 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The range for this measure will be 1 to 5, with higher values indicating higher quit intentions.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

1369 participants

Primary outcome timeframe

Up to 4 weeks

Results posted on

2025-09-12

Participant Flow

Participant milestones

Participant milestones
Measure	Label With Pictorial Health Warning Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Overall Study STARTED	457	456	456
Overall Study COMPLETED	452	454	452
Overall Study NOT COMPLETED	5	2	4

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Impact of E-cigarette Device Warnings

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Total n=1369 Participants Total of all reporting groups
Age, Customized 21-29 years	133 Participants n=93 Participants	130 Participants n=4 Participants	141 Participants n=27 Participants	404 Participants n=483 Participants
Age, Customized 30-39 years	170 Participants n=93 Participants	159 Participants n=4 Participants	166 Participants n=27 Participants	495 Participants n=483 Participants
Age, Customized 40-49 years	100 Participants n=93 Participants	100 Participants n=4 Participants	95 Participants n=27 Participants	295 Participants n=483 Participants
Age, Customized 50+ years	53 Participants n=93 Participants	68 Participants n=4 Participants	54 Participants n=27 Participants	175 Participants n=483 Participants
Sex/Gender, Customized Female	193 Participants n=93 Participants	197 Participants n=4 Participants	208 Participants n=27 Participants	598 Participants n=483 Participants
Sex/Gender, Customized Male	249 Participants n=93 Participants	237 Participants n=4 Participants	221 Participants n=27 Participants	707 Participants n=483 Participants
Sex/Gender, Customized Nonbinary/Another gender	14 Participants n=93 Participants	23 Participants n=4 Participants	27 Participants n=27 Participants	64 Participants n=483 Participants
Race/Ethnicity, Customized American Indian or Alaskan Native	5 Participants n=93 Participants	4 Participants n=4 Participants	3 Participants n=27 Participants	12 Participants n=483 Participants
Race/Ethnicity, Customized Asian	54 Participants n=93 Participants	25 Participants n=4 Participants	39 Participants n=27 Participants	118 Participants n=483 Participants
Race/Ethnicity, Customized Black or African American	78 Participants n=93 Participants	77 Participants n=4 Participants	74 Participants n=27 Participants	229 Participants n=483 Participants
Race/Ethnicity, Customized Hispanic	32 Participants n=93 Participants	51 Participants n=4 Participants	46 Participants n=27 Participants	129 Participants n=483 Participants
Race/Ethnicity, Customized Middle Eastern or North African	2 Participants n=93 Participants	8 Participants n=4 Participants	2 Participants n=27 Participants	12 Participants n=483 Participants
Race/Ethnicity, Customized Native Hawaiian or other Pacific Islander	1 Participants n=93 Participants	4 Participants n=4 Participants	3 Participants n=27 Participants	8 Participants n=483 Participants
Race/Ethnicity, Customized White	194 Participants n=93 Participants	196 Participants n=4 Participants	183 Participants n=27 Participants	573 Participants n=483 Participants
Race/Ethnicity, Customized Multiracial or another race or ethnicity	90 Participants n=93 Participants	91 Participants n=4 Participants	106 Participants n=27 Participants	287 Participants n=483 Participants
Race/Ethnicity, Customized Missing	0 Participants n=93 Participants	1 Participants n=4 Participants	0 Participants n=27 Participants	1 Participants n=483 Participants
Region of Enrollment United States	456 participants n=93 Participants	457 participants n=4 Participants	456 participants n=27 Participants	1369 participants n=483 Participants

PRIMARY outcome

Timeframe: Up to 4 weeks

The primary outcome is vaping quit intentions measured by 3 survey items at 5 time points: post-labeling (Visit 1) and at 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The range for this measure will be 1 to 5, with higher values indicating higher quit intentions.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Vaping Quit Intentions Score	2.5 score on a scale Standard Deviation 1.1	2.2 score on a scale Standard Deviation 1.0	2.5 score on a scale Standard Deviation 1.3

SECONDARY outcome

Timeframe: Up to 4 weeks

Knowledge of health harms from vaping will be measured by 5 survey items at 5 time points: post-labeling (Visit 1) and at 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will score each item for accuracy (correct or incorrect) and average the scores (% correct) for each time point and take an average across the time points. The range for this measure will be 0% to 100%, with higher values indicating more accurate knowledge).

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Knowledge Score	0.6 score on a scale Standard Deviation 0.3	0.4 score on a scale Standard Deviation 0.3	0.6 score on a scale Standard Deviation 0.3

SECONDARY outcome

Timeframe: Up to 4 weeks

Cognitive elaboration (thinking about the label) will be measured by 3 survey items at 4 time points: 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The range for this measure will be 1 to 5, with higher values indicating more cognitive elaboration.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=385 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=383 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=395 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Cognitive Elaboration Score	2.9 score on a scale Standard Deviation 0.9	2.0 score on a scale Standard Deviation 0.8	2.7 score on a scale Standard Deviation 0.9

SECONDARY outcome

Timeframe: Up to 4 weeks

Perceived likelihood of illness from vaping will be measured by 3 survey items at 5 time points: post-labeling (Visit 1) and at 1, 2, 3, and 4 weeks (Visit 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The range for this measure will be 1 to 5, with higher values indicating higher perceived likelihood.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Perceived Likelihood of Illness Score	3.1 score on a scale Standard Deviation 0.8	2.9 score on a scale Standard Deviation 0.9	3.1 score on a scale Standard Deviation 0.8

SECONDARY outcome

Timeframe: Up to 4 weeks

Negative affective reactions to the labels will be measured by 5 survey items at 5 time points: post-labeling (Visit 1) and at 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The range for this measure will be 1 to 5, with higher values indicating more negative affect.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Negative Affect Score	2.3 score on a scale Standard Deviation 1.0	1.4 score on a scale Standard Deviation 0.6	2.1 score on a scale Standard Deviation 0.9

SECONDARY outcome

Timeframe: Up to 4 weeks

Attention to the labels will be measured by 3 survey items at 4 time points: 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The range for this measure will be 1 to 5, with higher values indicating greater attention.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=385 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=383 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=395 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Attention Score	3.3 score on a scale Standard Deviation 0.9	2.8 score on a scale Standard Deviation 0.9	3.1 score on a scale Standard Deviation 0.9

SECONDARY outcome

Timeframe: Up to 4 weeks

Information seeking about the harms of vaping will be measured by 1 survey item at 4 time points: 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will score responses (0 times=0, 1-2 times=1.5, 3-5 times=4, 6+ times=6) and take an average across the time points. The range for this measure will be 0 times to 6 times), with higher values indicating more information seeking.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=385 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=383 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=395 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Information Seeking Score	1.4 number of times sought information Standard Deviation 1.3	0.8 number of times sought information Standard Deviation 1.0	1.3 number of times sought information Standard Deviation 1.3

SECONDARY outcome

Timeframe: Up to 4 weeks

Number of conversations with others about the labels, health harms caused by vaping, and quitting vaping will be measured by 3 survey items at 4 time points: 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The range for this measure will be 0 times to 100 times, with higher values indicating more conversations.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=385 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=383 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=395 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Number of Conversations in Past Week	1.7 number of conversations Standard Deviation 2.1	1.2 number of conversations Standard Deviation 1.8	1.5 number of conversations Standard Deviation 2.2

SECONDARY outcome

Timeframe: Up to 4 weeks

Positive vaping reinforcement attitudes will be measured by 3 survey items at 5 time points: post-labeling (Visit 1) and at 1, 2, 3, and 4 weeks (Visits 2-5). We will take an average across the time points. The range for this measure will be 1 to 5, with higher values indicating more positive vaping reinforcement attitudes.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Vaping Reinforcement Attitudes Score	4.1 units on a scale Standard Deviation 0.8	4.2 units on a scale Standard Deviation 0.8	4.1 units on a scale Standard Deviation 0.8

SECONDARY outcome

Timeframe: Up to 4 weeks

Subjective uncontrolled vaping (vaping more than the user prefers) will be measured by 3 survey items at 4 time points: 1, 2, 3, and 4 weeks (Visit 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The range for this measure will be 1 to 5, with higher values indicating vaping that is more uncontrolled.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=385 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=383 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=395 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Uncontrolled Vaping Score	2.4 score on a scale Standard Deviation 1.0	2.3 score on a scale Standard Deviation 1.0	2.4 score on a scale Standard Deviation 0.9

SECONDARY outcome

Timeframe: Up to 4 weeks

Number of times forgoing a vape in the last week will be measured by 4 survey items at 4 time points: 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will score responses (never=0, 1 time=1, 2 times=2, 3-5 times=4, 6+ times=6), average the items to create a score for each time point, and take an average across the time points. The range for this measure will be 0 times to 6 times, with higher values indicating more forgoing.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=385 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=383 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=395 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Number of Times Forgoing a Vape in Past Week	1.7 number of times forgoing a vape Standard Deviation 1.5	1.3 number of times forgoing a vape Standard Deviation 1.4	1.7 number of times forgoing a vape Standard Deviation 1.6

SECONDARY outcome

Timeframe: Up to 4 weeks

Made vaping quit attempt will be measured by 1 survey item (not vaping for 1 day or longer in the last week because they were trying to stop vaping) at 4 time points: 1, 2, 3, and 4 weeks (Visits 2-5). There will be an additional item (not vaping for 1 day or longer since the start of the study) at 4 weeks (Visit 5). Study investigators will score the items for any quit attempts: 0 (no quit attempts) or 1 (one or more quit attempt across the 4 weeks).

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Percent of Participants Who Made a Vaping Quit Attempt in Past 4 Weeks	204 Participants	211 Participants	217 Participants

SECONDARY outcome

Timeframe: At 4 weeks

Successful quitting of vaping during the trial will be measured by 1 survey item at 1 time point (participants' last survey, usually Visit 5). Study investigators will score the item for successful quitting: 0 (vaping on one or more of the last 7 days) or 1 (no vaping).

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Percent of Participants Who Successfully Quit Vaping	7.4 percentage of participants	3.7 percentage of participants	7.2 percentage of participants

SECONDARY outcome

Timeframe: Up to 4 weeks

Inaccurate risk perception of vaping (believing vaping is the same or more harmful than smoking cigarettes) will be measured by 1 survey item at 5 time points: post-labeling (Visit 1) and 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will score the item for accuracy (vaping less harmful than smoking cigarettes=correct; other answers=incorrect) and take an average across the time points. The range for this measure will be 0% (no correct answers) to 100% (all correct answers), with higher values indicating more accurate risk perceptions.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Inaccurate Risk Perception Score	0.44 proportion of correct answers Standard Deviation 0.43	0.48 proportion of correct answers Standard Deviation 0.43	0.42 proportion of correct answers Standard Deviation 0.42

SECONDARY outcome

Timeframe: Up to 4 weeks

Stigma (expecting the labels will cause social disapproval of vaping) will be measured by 3 survey items at 5 time points: post-labeling (Visit 1) and at 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The range for this measure will be 1 to 5, with higher values indicating more stigma.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Stigma Score	2.0 score on a scale Standard Deviation 0.9	1.6 score on a scale Standard Deviation 0.7	1.9 score on a scale Standard Deviation 0.8

SECONDARY outcome

Timeframe: Up to 4 weeks

Smoking quit intentions will be measured by 3 survey items at 5 time points: post-labeling (Visit 1) and 1, 2, 3, and 4 weeks (Visits 2-5). Study investigators will average the items to create a score for each time point and take an average across the time points. The construct will be assessed only among cigarette smokers. The range for this measure will be 1 to 5, with higher values indicating higher intentions.

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Mean Smoking Quit Intentions Score	2.5 score on a scale Standard Deviation 0.9	2.3 score on a scale Standard Deviation 0.9	2.4 score on a scale Standard Deviation 0.9

SECONDARY outcome

Timeframe: Up to 4 weeks

Made smoking quit attempt will be measured by 1 survey item (not smoking for 1 day or longer in the last week because they were trying to stop smoking) at 4 time points: 1, 2, 3, and 4 weeks (Visits 2-5). There will be an additional item (not smoking for 1 day or longer since the start of the study) at 4 weeks (Visit 5). Study investigators will score the items for any quit attempts: 0 (no quit attempts) or 1 (at least one quit attempt across the 4 weeks).

Outcome measures

Outcome measures
Measure	Label With Pictorial Health Warning n=457 Participants Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. Label with pictorial health warning: Labels with e-cigarette health warning that include the same text about health harms of vaping and corresponding pictorial images will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Neutral Statements About Vaping n=456 Participants Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. Label with neutral statements about vaping: Labels with neutral statements about vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 statements based on their assigned trial arm; at Visit 3, they will get 2 additional statements based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.	Label With Text Health Warning n=456 Participants Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. Label with text health warning: Labels with e-cigarette health warning that include text about health harms of vaping will be applied to participants' vaping devices and refills. At Visit 1, devices and refills will be labeled with 2 warnings based on their assigned trial arm; at Visit 3, they will get 2 additional warnings based on their assigned trial arm. The order of the 4 labels within this trial arm will be randomized using a Latin square design. Study investigators developed the text and design of these labels.
Percent of Participants Who Made a Smoking Quit Attempt in Past 4 Weeks	67.9 percentage of participants	63.1 percentage of participants	54.3 percentage of participants

Adverse Events

Label With Text Health Warning

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Label With Pictorial Health Warning

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Label With Neutral Statements About Vaping

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Principal Investigator

UNC

Phone: (919) 966-3282

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place