Random Assignment of Intervention Messages for Developing Personalized Decision Rules to Promote Physical Activity
Condition: Cardiovascular Risk Factor
Intervention: Short Message with Text and Optional Image
Intervention description: Messages can be up to 256 characters of text and with or without 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).
Phase: Phase 1
Study type: Interventional
Primary purpose: Prevention
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 82.0
Sex: All
Minimum age: 18 Years
Maximum age: 29 Years
Healthy volunteers: Accepts Healthy Volunteers

Summary:

      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 develop
      personalized dynamical models of physical activity (PA) under different weather and temporal
      conditions as well as in response to different types of intervention messages. This approach
      relies on having extensive observations within the person under varying conditions to develop
      a dynamical model of how different conditions interact with each other to predict how
      behavior changes in response to text messages. Complementary sub-models will be estimated for
      each participant to describe their behavioral responses under different weather conditions.
      Healthy but insufficiently active young adults (n=80) will wear an activity monitor and
      receive a variety of randomly-timed and randomly-selected notifications via smartphone. GPS
      coordinates at the time of messages delivery and receipt are recorded and used to look up
      weather indices at that location at that time. The work is exploratory/descriptive as we will
      be developing models to describe participants' responses to messages under different weather
      conditions. This work is needed to develop the decision rules for a subsequent behavioral
      intervention that will be developed and tested in a future project.
    

Eligibility criteria:

        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 use of a
             smartphone.

          -  Participants must own and carry an iPhone (running iOS version 10 or higher) or
             Android (running operating system 7 or higher) smartphone during waking hours.

        Exclusion Criteria:

          -  Participants engaging in 90 or more minutes of moderate- or greater intensity PA each
             week.

          -  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.