The JustWalk JITAI Study: A System Identification Experiment to Understand Just-in-Time States of Physical Activity

NCT05273437 | Completed Results

• 2 other identifiers: 8001325R01LM013107
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this system identification experiment is to estimate and validate dynamical computational models that can be used in a future a multi-timescale model-predictive controller. System identification is an experimental approach used in control systems engineering, which uses random and pseudo-random signal designs to experimentally manipulate independent variables, with the goal of producing dynamical models that can meaningfully predict individual responses to varying provision of support. A system identification is single subject/N-of-1 experimental design, whereby each person is their own control. This 9-month system identification experiment will experimentally vary daily suggested step goals and provision of notifications meant to inspire bouts of walking during different plausible just-in-time states. Results of this system identification experiment will then enable the development a future multi-timescale model-predictive controller-driven just-in-time adaptive intervention (JITAI) intended to increase steps/day. The system identification experiment will be conducted among N=50 inactive, adults aged 21 or over who have no preexisting conditions that preclude them from engaging in an exercise program, as determined using the physical activity readiness questionnaire.

Conditions

Physical Inactivity; Health Behavior; Healthy Lifestyle

Outcome Measures

Primary Outcomes (1)

• Steps/Day

  This will be measured continuously for the duration of the study via a Fitbit Versa, a wrist-worn, consumer-level activity tracker.

  Everyday from baseline to the end of study (for 270 days)

Study Arms (1)

System Identification

EXPERIMENTAL

All participants in the study will go through a system identification experiment everyday for 270 days.

Behavioral: System identification experiment for physical activity

Interventions

System identification experiment for physical activity BEHAVIORAL

The system identification experiment in Just Walk JITAI study has two key components that are the focus of the system identification experiment: daily adaptive step goal recommendations and within-day suggestions to either plan a bout of walking or to inspire reflection and, by extension, an increased urge to go for a walk.

System Identification

Eligibility Criteria

• Age: 21 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• inactive: engaging in less than 60 min/week of self-reported moderate intensity physical activity
• adults: aged 21 or older
• own a smartphone that can run HeartSteps (iOS or Android)

You may not qualify if:

• not proficient in English, or
• indicate medical problems that preclude physical activity as defined using physical activity readiness questionnaire (PAR-Q)

Sponsors & Collaborators

• University of California, San Diego: lead
• National Library of Medicine (NLM): collaborator

Study Sites (1)

University of California San Diego

San Diego, California, 92093, United States

Location

Related Publications (4)

• Hekler EB, Rivera DE, Martin CA, Phatak SS, Freigoun MT, Korinek E, Klasnja P, Adams MA, Buman MP. Tutorial for Using Control Systems Engineering to Optimize Adaptive Mobile Health Interventions. J Med Internet Res. 2018 Jun 28;20(6):e214. doi: 10.2196/jmir.8622.

  PMID: 29954725 BACKGROUND

• Phatak SS, Freigoun MT, Martin CA, Rivera DE, Korinek EV, Adams MA, Buman MP, Klasnja P, Hekler EB. Modeling individual differences: A case study of the application of system identification for personalizing a physical activity intervention. J Biomed Inform. 2018 Mar;79:82-97. doi: 10.1016/j.jbi.2018.01.010. Epub 2018 Feb 1.

  PMID: 29409750 BACKGROUND

• Korinek EV, Phatak SS, Martin CA, Freigoun MT, Rivera DE, Adams MA, Klasnja P, Buman MP, Hekler EB. Adaptive step goals and rewards: a longitudinal growth model of daily steps for a smartphone-based walking intervention. J Behav Med. 2018 Feb;41(1):74-86. doi: 10.1007/s10865-017-9878-3. Epub 2017 Sep 16.

  PMID: 28918547 BACKGROUND

• Park J, Kim M, El Mistiri M, Kha R, Banerjee S, Gotzian L, Chevance G, Rivera DE, Klasnja P, Hekler E. Advancing Understanding of Just-in-Time States for Supporting Physical Activity (Project JustWalk JITAI): Protocol for a System ID Study of Just-in-Time Adaptive Interventions. JMIR Res Protoc. 2023 Sep 26;12:e52161. doi: 10.2196/52161.

  PMID: 37751237 DERIVED

MeSH Terms

Conditions

Sedentary Behavior; Health Behavior

Interventions

Exercise

Condition Hierarchy (Ancestors)

Behavior

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Results Point of Contact

• Title: Dr. Eric Hekler
• Organization: University of California San Diego

ehekler@health.ucsd.edu

8584299370

Study Officials

• Eric Hekler, PhD

  University of California, San Diego

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: See study description for details. All participants will receive all intervention elements, with provision varying across time experimentally using procedures appropriate for system identification.

Study Record Dates

• First Submitted: February 22, 2022
• First Posted: March 10, 2022
• Study Start: April 11, 2022
• Primary Completion: May 15, 2023
• Study Completion: May 15, 2023
• Last Updated: November 19, 2024
• Results First Posted: November 19, 2024

Record last verified: 2024-10

Locations

US (1)