Aggression, Alcohol Drinking in College, Emotional Eating, Emotional Regulation
Conditions
Keywords
just-in-time adaptive intervention, micro-randomized trial, ecological momentary assessment, wearable sensor, hair cortisol, emotional volatility, college students
Brief summary
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. An optional part of the study collects one small hair sample, which is tested for two hormones related to stress and to status-linked behavior, so the researchers can see whether longer-term hormone levels relate to how people respond in the moment. The study is a pilot designed to test whether the approach works and to estimate how large its effects are.
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. An optional sub-study collects a single hair sample at the enrollment visit, assayed for cortisol and testosterone, to test whether early-life adversity moderates the association between chronic stress physiology and momentary reactive behavior.
Interventions
BEHAVIORALMomentary 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.
BEHAVIORALActive 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.
Sponsors
University of Florida
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
Micro-randomized trial. Each participant is repeatedly randomized at decision points across four weeks, so every participant contributes observations under both conditions rather than being assigned to a single group for the duration. At each available decision point, randomization with probability 0.5 determines whether a coping message is delivered; when a message is delivered, its type is selected at random from those eligible in that context. Approximately one hundred available randomized decision points are expected per participant. Crossover assignment is selected because it is the closest available model to a within-person repeated randomization design.
Eligibility
Sex/Gender
ALL
Age
18 Years to 89 Years
Healthy volunteers
Yes
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 * For the optional hair biomarker sub-study only: at least approximately 1 cm of hair at the posterior vertex, no scalp wound, rash, or dermatologic treatment at the collection site, and natural hair growth accessible at the collection site
Exclusion criteria
* Varsity student-athlete governed by the university athletic association * Unable to complete study procedures in English
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Momentary urge to post or reply reactively, score on a 7-point scale. | 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. |
| Momentary urge to drink alcohol, score on a 7-point scale. | 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. |
| Momentary emotional influence on eating, score on a 7-point scale. | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of enrolled participants retained to study end. | Through study completion, approximately 5 weeks per participant. | Number of participants completing the study divided by number enrolled. Pre-registered benchmark is 85 percent. |
| Proportion of sub-study participants providing a usable hair sample. | Enrollment visit | Number of usable hair samples divided by number of sub-study participants. Pre-registered benchmark is 90 percent. |
| Prompt helpfulness rating, score on a 7-point scale. | Week 3 and end of study, approximately week 5. | Participant rating of how helpful the coping prompts were, rated 1 to 7. |
| System Usability Scale total score | End of study, approximately week 5. | System Usability Scale (Brooke, 1996) total score, range 0 to 100, higher scores indicating better usability. |
| Momentary reactive online behavior since the previous check-in, self-reported occurrence | 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. |
| Number of standard drinks consumed since the previous check-in, self-reported count | 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. |
| Proportion of scheduled check-ins completed. | 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. |
| Loss-of-control eating rating, score on a 7-point scale. | 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. |
| Proportion of delivered prompts receiving a response | 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. |
| Proportion of waking hours with valid wearable data. | Through study completion, approximately 5 weeks per participant. | Hours of valid physiological data divided by estimated waking hours. Pre-registered benchmark is 80 percent. |
Countries
United States
Contacts
CONTACTYonghwan Chang, PhD
PRINCIPAL_INVESTIGATORYonghwan Chang, PhD
University of Florida
Outcome results
None listed