Adaptive Mobile Interventions to Reduce Cancer Risk Behaviors

The primary outcome will be change in participants' rating of smoking urge in EMA-post surveys, prompted 15 minutes after intervention message delivery, and controlling for the ratings in EMA-pre surveys. Urge will be assessed by a single item on a 5-point scale, ranging from 1-5; (1-very low, to 5-very high).

The primary outcome will be change in self-reported number of cigarettes smoked per day in the past week from baseline to 45-day follow-up.

The primary outcome will be assessment of the intervention app usability assessed by a slightly modified version of the 10-item System Usability Scale ("system" wording changed to "app"). Each item is assessed on a 5-point scale from 1 (strongly disagree) to 5 (strongly agree). The SUS total score ranges from 0-100, with higher scores indicating greater usability.

Smoking in the 15 minutes after message delivery will be assessed by a single item on a binary response scale (yes/no).

Other tobacco product use, including e-cigarette use, in the 15 minutes after message delivery will be assessed by a single item on a binary response scale (yes/no).

Change in rating of stress in EMA-post surveys, prompted 15 minutes after intervention message delivery, and controlling for the ratings in EMA-pre surveys. Stress will be assessed by a single item on a 5-point scale ranging from 1-5 (1-very low, to 5-very high).

Change in rating of negative affect in EMA-post surveys, prompted 15 minutes after intervention message delivery, and controlling for the ratings in EMA-pre surveys. Negative affect will be assessed by a single item on a 5-point scale ranging from 1-5 (1-very low, to 5-very high).

Rating of message helpfulness in EMA-post surveys, prompted 15 minutes after intervention message delivery. This will be assessed by a single item on a 5-point scale ranging from 1-5 (1-not at all helpful, to 5-extremely helpful).

Self-reported completion of intervention message recommendation in EMA-post surveys, prompted 15 minutes after intervention message delivery will be assessed by a single item on a binary response scale (yes/no).

Self-reported 7-day point prevalence abstinence (no smoking, not even a puff) will be assessed by a single item on a binary response scale (yes/no).

Change (reduction) in cigarettes smoked by at least 50% between baseline and 45-day follow-up. Reduction will be calculated based on self-reported number of cigarettes/day in the past week.

A tobacco quit attempt since the baseline assessment will be assessed by a single item on a binary response scale (yes/no).

Change in frequency and intensity of smoking urges will be assessed by two craving items from the Assessed with the Mood and Physical Symptoms Scale (MPSS) - subscale MPSS(C). Both items will be assessed on a 6-point scale from 0 (not at all / no urges) to 5 (all the time / extremely strong). Score range 0-10. Lower score better. Both items will be combined into the MPSS(C) subscale for analysis.

Change in psychological flexibility from baseline to 45-day follow-up will be assessed by the CompACT-15. The CompACT-15 total score ranges from 0-90, with higher scores indicating better psychological flexibility.

Change in smoking-specific experiential avoidance from baseline to 45-day follow-up will be assessed by the Avoidance and Inflexibility Scale (AIS). Items are scored on a scale of 1-5 and combined into a total score. Score range 13-65, higher total score indicates a more avoidant and inflexible response to internal states associated with smoking.

Switching to other tobacco products including e-cigarettes from baseline to 45-day follow-up will be assessed using questions about past 7-day use of cigarettes, e-cigarettes, cigars / cigarillos / little cigars, smokeless tobacco, and hookah / waterpipe. Participants will be coded as having switched if the participant does not report cigarette smoking, but use of another tobacco product at a follow-up assessment.