Recruiting

Tobacco Treatment

Sponsor:

Johns Hopkins Bloomberg School of Public Health

Code:

NCT07585357

Conditions

Smoking Cessation

Eligibility Criteria

Sex: All

Age: 18 - 40

Healthy Volunteers: Accepted

Interventions

Smartphone-based intervention messages

Study Details

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

Study ID

NCT07585357

Start date

Jul 6, 2026

Status verified date

Jul, 2026

Completion date

Sep, 2026

Anticipated

Primary completion date

Sep, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 40

Healthy Volunteers: Accepted

Inclusion Criteria:

  • 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.

Exclusion Criteria:

  • None

Study Design

Enrollment

7 participants

Anticipated

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: RL-informed intervention

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.

Interventions

Smartphone-based intervention messages

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

Primary outcome measure

  • Change in smoking urge as assessed by a single item [ Time Frame: 15 minutes after message delivery ]
  • Change in cigarettes smoked per day in past week as assessed by a single item [ Time Frame: Baseline, 45-day follow-up ]
  • System Usability as assessed by the System Usability Scale (SUS) [ Time Frame: 45-day follow-up ]

Central Contacts and Locations

Central contacts

Johannes Thrul, PhD

443-318-6633jthrul@jhu.edu

Locations

Johns Hopkins Bloomberg School of Public Health

Recruiting

Baltimore, Maryland, United States, 21205

Contacts

Johannes Thrul, PhD

443-318-6633jthrul@jhu.edu

More Information

Sponsor

Johns Hopkins Bloomberg School of Public Health

Last update posted

Jul 27, 2026

Last verified

Jul, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Johns Hopkins Bloomberg School of Public Health on 2026-07-27.