Precision Assignment of Intervention Messages to Promote Physical Activity - Precision AIM

Study Overview
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Brief Summary
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Our goal is to develop personalized decision rules for selecting the frequency, timing, and content of messages to promote physical activity. The objective of this project is to evaluate the acceptability and feasibility of two strategies for calibrating decision rules used to send those messages. Participants will wear an activity monitor for the collection of PA data and be randomly assigned to one of two adaptive intervention strategies. The decision rule for each participant will be refined on a monthly basis throughout the 6-month study based upon the accumulating data on how each participant is responding to different messages under different conditions. Our hypothesis is that more intensive intervention strategies will offer a better user experience because the resulting treatments will be experienced as more personalized.

Official Title
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Phase 1 Clinical Trial to Develop a Personalized Adaptive Text Message Intervention Using Control Systems Engineering Tools to Increase Physical Activity in Early Adulthood

Conditions
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Cardiovascular Risk Factor

Intervention / Treatment
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* Behavioral: Digital message (text + image)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants capable of reading, speaking and understanding English and of giving informed consent. Participants between the ages of 18-29 years. Participants must be free of visual impairment that would interfere with the receipt of text messages on their phone. Participants must be willing to wear a Fitbit Versa 3 almost continually (23.5 hours/day) for a 6- month period of time. Participants must own an iPhone or Android smartphone that they would be willing to download the custom Precision AIM and Fitbit app onto and sync with a Fitbit Versa 3. Participants interested in setting goals to increase their physical activity levels over the 6-month study. Exclusion Criteria: Participants engaging in 150 or more minutes of moderate- or greater intensity PA /week as assessed by a research grade accelerometer. Participants engaged in organized programs with mandated physical activity (e.g., varsity sports, ROTC). Participants with contraindications to normal physical activity on the Physical Activity Readiness Questionnaire. Participants who require an assistive device for mobility or have any other condition that may limit or prevent participation in moderate-intensity physical activity. Participants who are pregnant or planning to become pregnant within the next 6 months. Participants with a prior diagnosis of cancer, cardiovascular disease, diabetes or metabolic syndrome.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 29 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Aggressive adaptation strategy<br>Participants receive up to 6 messages/day to support achievement of their behavior change goal. Messages are only delivered outside of a participant-specific Do Not Disturb window (e.g., 11pm-8am). Messages with coordinating images are selected from three content domains: Move More, Sit Less, and Inspirational Quotes Unrelated to Movement within the first month. The decision rule for each participant will be refined on a monthly basis throughout the 6-month study based upon the accumulating data on how each participant is responding to different messages under different conditions. | Behavioral: Digital message (text + image)<br>* Messages can be up to 256 characters of text with an image. Move more and sit less messages were written to target established cognitive and affective constructs associated with physical activity (e.g., prompts to action plan, guidance for maximizing pleasure by regulating intensity).<br>|
| Experimental: Moderate adaptation strategy<br>Participants receive up to 3 messages/day to support achievement of their behavior change goal. Messages are only delivered outside of a participant-specific Do Not Disturb window (e.g., 11pm-8am). Messages with coordinating images are selected randomly from three content domains: Move More, Sit Less, and Inspirational Quotes Unrelated to Movement within the first month. The decision rule for each participant will be refined on a monthly basis throughout the 6-month study based upon the accumulating data on how each participant is responding to different messages under different conditions. | Behavioral: Digital message (text + image)<br>* Messages can be up to 256 characters of text with an image. Move more and sit less messages were written to target established cognitive and affective constructs associated with physical activity (e.g., prompts to action plan, guidance for maximizing pleasure by regulating intensity).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acceptability of messaging at 6 months | Self-reported preference for more, no change or fewer messages/day based on participant exit interviews coded by two blinded research assistants | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in total physical activity volume from run-in period | Actigraph-assessed total activity counts during a 1-week monitoring period at baseline versus end of study | Baseline and 6 months | 
| Change in moderate-to-vigorous physical activity duration from run-in period (baseline) to 6 months(baseline) to 6 months | Actigraph-assessed min/week of moderate (or higher) physical activity duration during a 1 week monitoring period at baseline versus end of study | Baseline and 6 months |