Just-in-Time Coping Prompts for Reactive Digital Behavior in College Students (REACT)

August 24, 2026 updated by: University of Florida

REACT: A Just-in-Time Adaptive Intervention to Reduce Reactive Digital Behavior in College Students

This study looks at the moments when college students feel a strong emotional swing, and how those moments relate to reacting online when upset, drinking alcohol, and eating in response to emotions. Participants wear a wrist device and answer brief check-ins on their phone several times a day for about five weeks. During part of that time, a study app sometimes sends a short coping message at moments when the wrist device and check-ins suggest emotions are shifting quickly. Whether a message is sent at any given moment is decided at random, and the study compares what participants do in the short window afterward. The study is a pilot designed to test whether the approach is feasible and to estimate how large its effects are.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

REACT is a five-week micro-randomized trial in University of Florida students age 18 and older. Participants complete a baseline battery, wear a Garmin Venu 3, and respond to five to six smartphone check-ins per day. Week one is a no-prompt run-in that establishes each participant's own baseline distribution of momentary affective variability, indexed by the mean square of successive differences on consecutive affect ratings. From week two through week five, the app evaluates up to six decision points per day. A decision point is flagged when the participant's current variability exceeds their own 80th percentile threshold, computed within person rather than against a group average. At each available decision point the app randomizes with probability 0.5 whether to deliver a brief coping message, and if so selects a message type from those eligible in that context. Availability rules exclude sleep, stale device data, a 60-minute cooldown, a daily cap, and any safety override. Proximal outcomes are drawn from the first check-in within two hours after the decision point. Analysis uses weighted and centered least squares to estimate causal excursion effects, with pre-specified moderators.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
80

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Yonghwan Chang, PhD
  • Phone Number: 352-294-1664
  • Email: yhchang@ufl.edu

Study Locations

  • United States
    • Florida
      • Gainesville, Florida, United States, 32611
        • University of Florida
        • Contact:
        • Principal Investigator:
          • Yonghwan Chang, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Currently enrolled University of Florida student
  • Age 18 years or older
  • Owns a smartphone used daily
  • Willing to wear a wrist-worn device and complete brief check-ins several times daily for approximately five weeks

Exclusion Criteria:

  • Varsity student-athlete governed by the university athletic association
  • Unable to complete study procedures in English

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Coping prompt delivered
Decision points at which the randomization outcome is to deliver a brief cognitive-behavioral or acceptance-based coping message. Message type is selected at random from those eligible in the participant's current context. Every participant contributes decision points to this condition.
Behavioral: Momentary coping prompt
A single short message of one to three sentences delivered to the participant's smartphone at a randomized decision point, taking roughly fifteen to thirty seconds to read. Messages apply cognitive-behavioral techniques including thought records, perspective-taking, decatastrophizing, cost-benefit checks, implementation intentions, and behavioral redirection, or acceptance-based techniques including cognitive defusion, acceptance, values anchoring, urge surfing, and present-moment grounding. Delivery is capped at four messages per day with a minimum sixty-minute interval and is confined to participant-set waking hours. Messages may be dismissed without responding.
Active Comparator: No coping prompt or active control message
Decision points at which the randomization outcome is not to deliver a coping message. A brief neutral, non-directive acknowledgment message may be delivered as an active control so that receiving any message can be separated from receiving a coping message. Every participant contributes decision points to this condition.
Behavioral: Active control message
A brief neutral acknowledgment message matched to the coping messages on delivery mechanism and approximate length, containing no coping technique or behavioral suggestion.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Momentary urge to post or reply reactively, score on a 7-point scale.
Time Frame: Within 2 hours after each randomized decision point, across weeks 2 to 5.
Self-reported urge to post or reply about something upsetting, rated 1 to 7 at the first check-in within two hours after a randomized decision point. Higher scores indicate greater urge. Analyzed as a causal excursion effect comparing decision points at which a coping message was delivered with those at which it was not.
Within 2 hours after each randomized decision point, across weeks 2 to 5.
Momentary urge to drink alcohol, score on a 7-point scale.
Time Frame: Within 2 hours after each randomized decision point, across weeks 2 to 5.
Self-reported current urge to drink alcohol, rated 1 to 7 at the first check-in within two hours after a randomized decision point. Higher scores indicate greater urge. Analyzed as a causal excursion effect.
Within 2 hours after each randomized decision point, across weeks 2 to 5.
Momentary emotional influence on eating, score on a 7-point scale.
Time Frame: Within 2 hours after each randomized decision point, across weeks 2 to 5.
Self-reported rating of how much emotions influenced eating since the previous check-in, rated 1 to 7 at the first check-in within two hours after a randomized decision point. Analyzed as a causal excursion effect.
Within 2 hours after each randomized decision point, across weeks 2 to 5.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Proportion of delivered prompts receiving a response
Time Frame: Through study completion, approximately 5 weeks per participant.
Number of prompts receiving a rating response divided by number of prompts delivered. Pre-registered benchmark is 60 percent.
Through study completion, approximately 5 weeks per participant.
Proportion of enrolled participants retained to study end.
Time Frame: Through study completion, approximately 5 weeks per participant.
Number of participants completing the study divided by number enrolled. Pre-registered benchmark is 85 percent.
Through study completion, approximately 5 weeks per participant.
Momentary reactive online behavior since the previous check-in, self-reported occurrence
Time Frame: Within 2 hours after each randomized decision point, across weeks 2 to 5.
Self-reported occurrence of posting or replying while upset since the previous check-in, reported yes or no at the first check-in within two hours after a randomized decision point.
Within 2 hours after each randomized decision point, across weeks 2 to 5.
Number of standard drinks consumed since the previous check-in, self-reported count
Time Frame: Within 2 hours after each randomized decision point, across weeks 2 to 5.
Self-reported number of standard drinks consumed since the previous check-in.
Within 2 hours after each randomized decision point, across weeks 2 to 5.
Loss-of-control eating rating, score on a 7-point scale
Time Frame: Within 2 hours after each randomized decision point, across weeks 2 to 5
Self-reported sense of losing control while eating since the previous check-in, rated 1 to 7.
Within 2 hours after each randomized decision point, across weeks 2 to 5
Proportion of scheduled check-ins completed
Time Frame: Through study completion, approximately 5 weeks per participant.
Number of completed check-ins divided by number of scheduled check-ins. Pre-registered feasibility benchmark is 75 percent.
Through study completion, approximately 5 weeks per participant.
Proportion of waking hours with valid wearable data
Time Frame: Through study completion, approximately 5 weeks per participant.
Hours of valid physiological data divided by estimated waking hours. Pre-registered benchmark is 80 percent.
Through study completion, approximately 5 weeks per participant.
Prompt helpfulness rating, score on a 7-point scale
Time Frame: Week 3 and end of study, approximately week 5.
Participant rating of how helpful the coping prompts were, rated 1 to 7.
Week 3 and end of study, approximately week 5.
System Usability Scale total score.
Time Frame: End of study, approximately week 5.
System Usability Scale (Brooke, 1996) total score, range 0 to 100, higher scores indicating better usability.
End of study, approximately week 5.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Florida

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Yonghwan Chang, PhD, University of Florida

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 23, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 24, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 27, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB202600940
  • 00135244 (Other Grant/Funding Number: University of Florida Research Opportunity Seed Fund)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared outside the research team. This is a pilot study collecting sensitive behavioral and biological data from a small identifiable campus population, and the informed consent does not provide for external sharing of individual-level data. Aggregate results will be published.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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