Trial Outcomes & Findings for Project MARS: Mobile-Assistance for Regulating Smoking (NCT NCT04376489)
NCT ID: NCT04376489
Last Updated: 2026-07-29
Results Overview
Within-person randomization occurred (2:1:1) up to 6 times daily for 10 days to (a) no intervention prompt (b) prompt to engage with a low effort strategy or (c) prompt to engage with a more effortful strategy. Proximal Engagement (PE) with strategies is a binary indicator of engagement, coded as 1 (engaged) if the participant answered "Yes" to at least one of the three items below and as 0 (not engaged) if they answered "No" to all three items below. The three EMA items used to operationalize PE were: 1. "Think about the most recent tip or activity recommended by MARS. Did you use it in the last hour?" (Yes or No); 2. "In the last hour, did you use any other tip or activity recommended by MARS?" (Yes or No); 3. "In the last hour, did you use any other tip or activity not included in MARS?" (Yes or No). Proportions were first determined for each participant, then averaged across participants. There were up to 60 decision points per participant.
COMPLETED
NA
114 participants
1 hour following micro-randomization
2026-07-29
Participant Flow
Participant milestones
| Measure |
Current Smoker
Within-participant micro-randomization occurred up to six times daily (2:1:1) to either (a) no intervention prompt; (b) a prompt recommending a brief (low effort) self-regulatory strategy; or (c) a prompt recommending a more effortful self-regulatory strategy.
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|---|---|
|
Overall Study
STARTED
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114
|
|
Overall Study
COMPLETED
|
63
|
|
Overall Study
NOT COMPLETED
|
51
|
Reasons for withdrawal
| Measure |
Current Smoker
Within-participant micro-randomization occurred up to six times daily (2:1:1) to either (a) no intervention prompt; (b) a prompt recommending a brief (low effort) self-regulatory strategy; or (c) a prompt recommending a more effortful self-regulatory strategy.
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|---|---|
|
Overall Study
Death
|
1
|
|
Overall Study
Attended the visit with staff but did not complete the questionnaire
|
16
|
|
Overall Study
Lost to Follow-up
|
25
|
|
Overall Study
Withdrawal by Subject
|
9
|
Baseline Characteristics
Project MARS: Mobile-Assistance for Regulating Smoking
Baseline characteristics by cohort
| Measure |
Current Smoker
n=111 Participants
Within-participant micro-randomization occurred up to six times daily (2:1:1) to either (a) no intervention prompt; (b) a prompt recommending a brief (low effort) self-regulatory strategy; or (c) a prompt recommending a more effortful self-regulatory strategy.
|
|---|---|
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Age, Continuous
|
43.8 years
STANDARD_DEVIATION 11.5 • n=9 Participants
|
|
Sex: Female, Male
Female
|
71 Participants
n=9 Participants
|
|
Sex: Female, Male
Male
|
40 Participants
n=9 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
30 Participants
n=9 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
81 Participants
n=9 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
2 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Black or African American
|
39 Participants
n=9 Participants
|
|
Race (NIH/OMB)
White
|
64 Participants
n=9 Participants
|
|
Race (NIH/OMB)
More than one race
|
6 Participants
n=9 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=9 Participants
|
|
Region of Enrollment
United States
|
111 participants
n=9 Participants
|
|
Partner Status
Has Partner
|
47 Participants
n=9 Participants
|
|
Partner Status
Does Not Have Partner
|
60 Participants
n=9 Participants
|
|
Partner Status
Did not disclose
|
4 Participants
n=9 Participants
|
|
Tobacco History
|
13.7 number of cigarettes smoked per day
STANDARD_DEVIATION 7.97 • n=9 Participants
|
|
Income
Less than or equal to $9,999:
|
15 Participants
n=9 Participants
|
|
Income
$10,000 - $19,999:
|
13 Participants
n=9 Participants
|
|
Income
$20,000 - $29,999:
|
17 Participants
n=9 Participants
|
|
Income
$30,000 - $39,999:
|
8 Participants
n=9 Participants
|
|
Income
$40,000 - $49,999:
|
10 Participants
n=9 Participants
|
|
Income
$50,000 - $59,999:
|
9 Participants
n=9 Participants
|
|
Income
$60,000 - $69,999:
|
8 Participants
n=9 Participants
|
|
Income
$70,000 - $79,999:
|
5 Participants
n=9 Participants
|
|
Income
$80,000 - $89,999:
|
3 Participants
n=9 Participants
|
|
Income
$90,000 - $99,999:
|
3 Participants
n=9 Participants
|
|
Income
$100,000 and greater:
|
10 Participants
n=9 Participants
|
|
Income
Did not disclose:
|
10 Participants
n=9 Participants
|
PRIMARY outcome
Timeframe: 1 hour following micro-randomizationPopulation: Of the 114 who started the study, 111 were non-beta participants. However, due to sub-par fidelity to the study protocol, 99 were used for analyzing results.
Within-person randomization occurred (2:1:1) up to 6 times daily for 10 days to (a) no intervention prompt (b) prompt to engage with a low effort strategy or (c) prompt to engage with a more effortful strategy. Proximal Engagement (PE) with strategies is a binary indicator of engagement, coded as 1 (engaged) if the participant answered "Yes" to at least one of the three items below and as 0 (not engaged) if they answered "No" to all three items below. The three EMA items used to operationalize PE were: 1. "Think about the most recent tip or activity recommended by MARS. Did you use it in the last hour?" (Yes or No); 2. "In the last hour, did you use any other tip or activity recommended by MARS?" (Yes or No); 3. "In the last hour, did you use any other tip or activity not included in MARS?" (Yes or No). Proportions were first determined for each participant, then averaged across participants. There were up to 60 decision points per participant.
Outcome measures
| Measure |
Intervention Prompt
n=1924 decision points
Participants were randomized to a prompt recommending a self-regulatory strategy during these decision points.
|
No Intervention Prompt
n=1934 decision points
Participants were randomized to no intervention prompt during these decision points.
|
|---|---|---|
|
Proportion of Randomized Decision Points in Which Participant Reported Proximal Engagement by Randomized Assignment
|
0.655 Proportion of decision points
Interval 0.589 to 0.716
|
0.584 Proportion of decision points
Interval 0.506 to 0.658
|
PRIMARY outcome
Timeframe: 1 hour following micro-randomizationPopulation: Of the 114 who started the study, 111 were non-beta participants. However, due to sub-par fidelity to the study protocol, 99 were used for analyzing results.
Within-person randomization occurred (2:1:1) up to 6 times daily for 10 days to (a) no intervention prompt (b) prompt to engage with a low effort strategy or (c) prompt to engage with a more effortful strategy. Proximal Engagement (PE) with strategies is a binary indicator of engagement, coded as 1 (engaged) if the participant answered "Yes" to at least one of the three items below and as 0 (not engaged) if they answered "No" to all three items below. The three EMA items used to operationalize PE were: 1. "Think about the most recent tip or activity recommended by MARS. Did you use it in the last hour?" (Yes or No); 2. "In the last hour, did you use any other tip or activity recommended by MARS?" (Yes or No); 3. "In the last hour, did you use any other tip or activity not included in MARS?" (Yes or No). Proportions were first determined for each participant, then averaged across participants. There were up to 60 decision points per participant.
Outcome measures
| Measure |
Intervention Prompt
n=997 decision points
Participants were randomized to a prompt recommending a self-regulatory strategy during these decision points.
|
No Intervention Prompt
n=927 decision points
Participants were randomized to no intervention prompt during these decision points.
|
|---|---|---|
|
Proportion of Randomized Decision Points in Which the Participant Reported Proximal Engagement by Randomized Assignment.
|
0.602 Proportion of decision points
Interval 0.53 to 0.67
|
0.713 Proportion of decision points
Interval 0.641 to 0.776
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SECONDARY outcome
Timeframe: approximately 1 hour following the decision pointPopulation: Of the 114 who started the study, 111 were non-beta participants. However, due to sub-par fidelity to the study protocol, 99 were used for analyzing results.
Proximal Cigarette Use (PCU) was assessed with the EMA item, "Since the last assessment, did you use any of the following (check all that apply): Cigarettes; Vape pen, JUUL, or e-cigarettes; Cigars, cigarillos, or little cigars; Smokeless tobacco/snus/dissolvable tobacco; Marijuana/Cannabis; Alcohol; None." A binary indicator of Proximal Cigarette Use was created, coded as 1 if the response included "Cigarettes" and 0 otherwise. This outcome measure reports the proportion that reported PCU at 1 hour following micro-randomization. The intent of this Outcome Measures is to report overall PCU use according to participant's self-reported engagement with self-regulatory strategies.
Outcome measures
| Measure |
Intervention Prompt
n=3858 decision points
Participants were randomized to a prompt recommending a self-regulatory strategy during these decision points.
|
No Intervention Prompt
Participants were randomized to no intervention prompt during these decision points.
|
|---|---|---|
|
Proximal Cigarette Use
|
0.33 Proportion of Decision Points
Interval 0.29 to 0.38
|
—
|
SECONDARY outcome
Timeframe: approximately 1 hour following the decision pointPopulation: Of the 114 who started the study, 111 were non-beta participants. However, due to sub-par fidelity to the study protocol, 99 were used for analyzing results.
Proximal Nicotine-Containing Non-Cessation Product Use (NCNCP) was assessed with the EMA item, "Since the last assessment, did you use any of the following (check all that apply): Cigarettes; Vape pen, JUUL, or e-cigarettes; Cigars, cigarillos, or little cigars; Smokeless tobacco/snus/dissolvable tobacco; Marijuana/Cannabis; Alcohol; None." A binary indicator of Proximal NCNCP Use was created, coded as 1 if the response included "Cigarettes", "Vape pen, JUUL, or e-cigarette," "Cigars, cigarillos, or little cigars," or "Smokeless tobacco/snus/dissolvable tobacco," and 0 otherwise. This outcome measure will report the proportion that reported NCNCP Use at 1 hour following micro-randomization.
Outcome measures
| Measure |
Intervention Prompt
n=3858 decision point
Participants were randomized to a prompt recommending a self-regulatory strategy during these decision points.
|
No Intervention Prompt
Participants were randomized to no intervention prompt during these decision points.
|
|---|---|---|
|
Proximal Nicotine-Containing Non-Cessation Product (NCNCP) Use
|
0.34 Proportion of decision points
Interval 0.3 to 0.39
|
—
|
SECONDARY outcome
Timeframe: approximately 1 hour following the decision pointPopulation: Of the 114 who started the study, 111 were non-beta participants. However, due to sub-par fidelity to the study protocol, 99 were used for analyzing results.
Proximal Nicotine-Containing Non-Cessation Product Use (PTPU) was assessed with the EMA item, "Since the last assessment, did you use any of the following (check all that apply): Cigarettes; Vape pen, JUUL, or e-cigarettes; Cigars, cigarillos, or little cigars; Smokeless tobacco/snus/dissolvable tobacco; Marijuana/Cannabis; Alcohol; None." A binary indicator of PTPU was created, coded as 1 if the response included "Cigarettes", "Cigars, cigarillos, or little cigars," or "Smokeless tobacco/snus/dissolvable tobacco," and 0 otherwise. This outcome measure will report the proportion that reported PTPU at 1 hour following micro-randomization.
Outcome measures
| Measure |
Intervention Prompt
n=3858 decision point
Participants were randomized to a prompt recommending a self-regulatory strategy during these decision points.
|
No Intervention Prompt
Participants were randomized to no intervention prompt during these decision points.
|
|---|---|---|
|
Proximal Tobacco Product Use (PTPU) Use
|
0.34 Proportion of decision points
Interval 0.3 to 0.39
|
—
|
Adverse Events
Current Smoker
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Current Smoker
n=114 participants at risk
Within-participant micro-randomization occurred up to six times daily (2:1:1) to either (a) no intervention prompt; (b) a prompt recommending a brief (low effort) self-regulatory strategy; or (c) a prompt recommending a more effortful self-regulatory strategy.
|
|---|---|
|
Skin and subcutaneous tissue disorders
Pain of Skin
|
1.8%
2/114 • Number of events 2 • Adverse events and serious adverse events were collected while participants were one study, up to 10 days
|
Additional Information
IIT Data Management Team
Research Compliance Office, Huntsman Cancer Institute
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place