Project MARS: Mobile-Assistance for Regulating Smoking

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:

• "Think about the most recent tip or activity recommended by MARS. Did you use it in the last hour?" (Yes or No);
• "In the last hour, did you use any other tip or activity recommended by MARS?" (Yes or No);
• "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.

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:

• "Think about the most recent tip or activity recommended by MARS. Did you use it in the last hour?" (Yes or No);
• "In the last hour, did you use any other tip or activity recommended by MARS?" (Yes or No);
• "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.

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.

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.

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.