Adaptive Mobile Interventions to Reduce Cancer Risk Behaviors

NCT07585357 | Not Yet Recruiting

• 1 other identifier: IRB00033759
• Study Type: interventional
• Target: 7
• Locations: 1 country
• Sites: 1

Brief Summary

Tobacco use remains the leading cause of preventable death, causing over 400,000 annual deaths in the United States alone. Smartphone-based interventions, particularly those leveraging real-time adaptive messaging, represent a promising yet underutilized approach to delivering personalized tobacco and cannabis treatment. The investigator's ongoing NCI funded micro-randomized trial (MRT; R01 CA246590) has shown initial feasibility in reducing smoking urges through situationally tailored cognitive-behavioral therapy (CBT) and mindfulness-based acceptance and commitment-based therapy (ACT) messages triggered by real-time contextual data (e.g., geolocation, momentary stress). To advance from a static MRT framework to a dynamic, data-driven just-in-time adaptive intervention (JITAI), this project aims to develop, test, and refine a reinforcement learning (RL) algorithm that can continuously adapt to user needs in real-time, enhancing treatment outcomes for various tobacco and cannabis products. To ensure optimal usability and engagement, the investigators will conduct user-centered testing with the developed RL-based intervention delivery in one cohort (N=7) over 45 days. This will include usability assessment via the System Usability Scale, analysis of app interaction metrics, and semi-structured interviews to gather feedback for refining message content, timing, and design.

Conditions

Smoking Cessation

Outcome Measures

Primary Outcomes (3)

• Change in smoking urge as assessed by a single item

  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).

  15 minutes after message delivery

• Change in cigarettes smoked per day in past week as assessed by a single item

  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.

  Baseline, 45-day follow-up

• System Usability as assessed by the System Usability Scale (SUS)

  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.

  45-day follow-up

Secondary Outcomes (13)

• Smoking since intervention message delivery as assessed by a single item

  15 minutes after message delivery

• Other tobacco product use since intervention message delivery as assessed by a single item

  15 minutes after message delivery

• Change in stress as assessed by a single item

  15 minutes after message delivery

• Change in negative affect as assessed by a single item

  15 minutes after message delivery

• Message helpfulness as assessed by a single item

  15 minutes after message delivery

Study Arms (1)

RL-informed intervention

EXPERIMENTAL

Participants complete a 14-day Ecological Momentary Assessment (EMA) training phase using a smartphone app (MetricWire), during which the participant responds to up to 3 randomly prompted and cigarette-triggered EMA surveys per day while the app passively collects GPS data. These data are used to identify high-risk locations and time periods and to inform a previously trained reinforcement learning (RL) algorithm. During the subsequent 30-day intervention phase, the RL algorithm delivers personalized intervention messages (cognitive-behavioral therapy \[CBT\], acceptance and commitment therapy \[ACT\], or attention control) triggered by geofence entry at high-risk locations.

Behavioral: Smartphone-based intervention messages

Interventions

Smartphone-based intervention messages BEHAVIORAL

Intervention messages will suggest strategies of coping with smoking urges in the moment.

RL-informed intervention

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• live in the U.S.;
• are between 18 and 40 years of age;
• own a smartphone with iOS and Android operating system and GPS capabilities;
• are carrying smartphone every day;
• are willing to participate in the study for 44 days and give the research team access to the phone GPS data;
• have smoked ≥100 cigarettes in the participant's life and currently smoke at least 3 cigarettes per day on 5 or more days of the week;
• are planning to quit smoking within the next 30 days.

You may not qualify if:

• None

Sponsors & Collaborators

• Johns Hopkins Bloomberg School of Public Health: lead
• Maryland Cigarette Restitution: collaborator

Study Sites (1)

Johns Hopkins Bloomberg School of Public Health

Baltimore, Maryland, 21205, United States

Location

MeSH Terms

Conditions

Smoking Cessation

Condition Hierarchy (Ancestors)

Health Behavior; Behavior

Study Officials

• Johannes Thrul, PhD

  Johns Hopkins Bloomberg School of Public Health

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Johannes Thrul, PhD

CONTACT

443-318-6633; jthrul@jhu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 7, 2026
• First Posted: May 13, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026
• Last Updated: May 13, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ANALYTIC CODE

Locations

US (1)