Trial Outcomes & Findings for The JustWalk JITAI Study: A System Identification Experiment to Understand Just-in-Time States of Physical Activity (NCT NCT05273437)

NCT ID: NCT05273437

Last Updated: 2024-11-19

Results Overview

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

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

50 participants

Primary outcome timeframe

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

Results posted on

2024-11-19

Participant Flow

Participant milestones

Participant milestones
Measure
System Identification
All participants in the study will go through a system identification experiment everyday for 270 days. System identification experiment for physical activity: The system identification experiment in Just Walk JITAI study has two key components that are the focus of the system identification experiment: walking suggestions and daily step goals. To achieve the desired dynamics on the timescale of interest, we used 2 input signals, one for each of the 2 components. Although our study design enables traditional statistical analyses to examine the impact of intervention components on behavioral outcomes, that is not the primary focus of a system ID experiment. The primary goal of a system ID experiment is to estimate and validate dynamical computational models that are validated based on their ability to predict the future responses of each individual's behavior across time. These aims are achieved by having different intervention components-suggestions to walk in the next 3 hours and adaptive goal setting-delivered at different timescales and orthogonally, that is, statistically independent of each other.
Overall Study
STARTED
50
Overall Study
COMPLETED
48
Overall Study
NOT COMPLETED
2

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

There were 3 missing data for this measure.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
System Identification
n=48 Participants
All participants in the study will go through a system identification experiment everyday for 270 days. System identification experiment for physical activity: The system identification experiment in Just Walk JITAI study has two key components that are the focus of the system identification experiment: walking suggestions and daily step goals. To achieve the desired dynamics on the timescale of interest, we used 2 input signals, one for each of the 2 components. Although our study design enables traditional statistical analyses to examine the impact of intervention components on behavioral outcomes, that is not the primary focus of a system ID experiment. The primary goal of a system ID experiment is to estimate and validate dynamical computational models that are validated based on their ability to predict the future responses of each individual's behavior across time. These aims are achieved by having different intervention components-suggestions to walk in the next 3 hours and adaptive goal setting-delivered at different timescales and orthogonally, that is, statistically independent of each other.
Age, Categorical
<=18 years
0 Participants
n=48 Participants
Age, Categorical
Between 18 and 65 years
48 Participants
n=48 Participants
Age, Categorical
>=65 years
0 Participants
n=48 Participants
Age, Continuous
38.4 years
STANDARD_DEVIATION 9.3 • n=48 Participants
Sex: Female, Male
Female
29 Participants
n=45 Participants • There were 3 missing data for this measure.
Sex: Female, Male
Male
16 Participants
n=45 Participants • There were 3 missing data for this measure.
Ethnicity (NIH/OMB)
Hispanic or Latino
8 Participants
n=45 Participants • There were 3 missing data for this measure.
Ethnicity (NIH/OMB)
Not Hispanic or Latino
37 Participants
n=45 Participants • There were 3 missing data for this measure.
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=45 Participants • There were 3 missing data for this measure.
Race (NIH/OMB)
American Indian or Alaska Native
1 Participants
n=44 Participants • There were 4 missing data for this measure.
Race (NIH/OMB)
Asian
14 Participants
n=44 Participants • There were 4 missing data for this measure.
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
3 Participants
n=44 Participants • There were 4 missing data for this measure.
Race (NIH/OMB)
Black or African American
2 Participants
n=44 Participants • There were 4 missing data for this measure.
Race (NIH/OMB)
White
17 Participants
n=44 Participants • There were 4 missing data for this measure.
Race (NIH/OMB)
More than one race
2 Participants
n=44 Participants • There were 4 missing data for this measure.
Race (NIH/OMB)
Unknown or Not Reported
5 Participants
n=44 Participants • There were 4 missing data for this measure.
Region of Enrollment
United States
48 participants
n=48 Participants

PRIMARY outcome

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

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

Outcome measures

Outcome measures
Measure
System Identification
n=44 Participants
All participants in the study will go through a system identification experiment everyday for 270 days. System identification experiment for physical activity: The system identification experiment in Just Walk JITAI study has two key components that are the focus of the system identification experiment: walking suggestions and daily step goals. To achieve the desired dynamics on the timescale of interest, we used 2 input signals, one for each of the 2 components. Although our study design enables traditional statistical analyses to examine the impact of intervention components on behavioral outcomes, that is not the primary focus of a system ID experiment. The primary goal of a system ID experiment is to estimate and validate dynamical computational models that are validated based on their ability to predict the future responses of each individual's behavior across time. These aims are achieved by having different intervention components-suggestions to walk in the next 3 hours and adaptive goal setting-delivered at different timescales and orthogonally, that is, statistically independent of each other.
Steps/Day
Participant 1
4048.4 Steps/day
Steps/Day
Participant 2
1074.4 Steps/day
Steps/Day
Participant 3
1645.8 Steps/day
Steps/Day
Participant 4
1749.1 Steps/day
Steps/Day
Participant 5
2991.3 Steps/day
Steps/Day
Participant 6
NA Steps/day
Daily intervention effect on Weekend is not available.
Steps/Day
Participant 7
1254.6 Steps/day
Steps/Day
Participant 8
2168.3 Steps/day
Steps/Day
Participant 9
1471.5 Steps/day
Steps/Day
Participant 10
2003.8 Steps/day
Steps/Day
Participant 11
NA Steps/day
Daily intervention effect on both Weekday and Weekend are not available.
Steps/Day
Participant 12
1333.0 Steps/day
Steps/Day
Participant 13
1168.5 Steps/day
Steps/Day
Participant 14
2577.2 Steps/day
Steps/Day
Participant 15
2703.3 Steps/day
Steps/Day
Participant 16
1819.4 Steps/day
Steps/Day
Participant 17
1930.3 Steps/day
Steps/Day
Participant 18
2229.0 Steps/day
Steps/Day
Participant 19
295.0 Steps/day
Steps/Day
Participant 20
1887.8 Steps/day
Steps/Day
Participant 21
1563.3 Steps/day
Steps/Day
Participant 22
704.9 Steps/day
Steps/Day
Participant 23
1703.3 Steps/day
Steps/Day
Participant 24
156.4 Steps/day
Steps/Day
Participant 25
1187.5 Steps/day
Steps/Day
Participant 26
3697.9 Steps/day
Steps/Day
Participant 27
1138.1 Steps/day
Steps/Day
Participant 28
1470.2 Steps/day
Steps/Day
Participant 29
919.0 Steps/day
Steps/Day
Participant 30
NA Steps/day
Daily intervention effect on both Weekday and Weekend are not available.
Steps/Day
Participant 31
1015.9 Steps/day
Steps/Day
Participant 32
NA Steps/day
Daily intervention effect on both Weekday and Weekend are not available.
Steps/Day
Participant 33
449.8 Steps/day
Steps/Day
Participant 34
1228.2 Steps/day
Steps/Day
Participant 35
1074.1 Steps/day
Steps/Day
Participant 36
967.1 Steps/day
Steps/Day
Participant 37
2928.6 Steps/day
Steps/Day
Participant 38
2608.3 Steps/day
Steps/Day
Participant 39
738.2 Steps/day
Steps/Day
Participant 40
2677.5 Steps/day
Steps/Day
Participant 41
783.5 Steps/day
Steps/Day
Participant 42
1631.8 Steps/day
Steps/Day
Participant 43
1387.4 Steps/day
Steps/Day
Participant 44
1008.3 Steps/day

Adverse Events

System Identification

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Eric Hekler

University of California San Diego

Phone: 8584299370

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place