Precision Public Health: Enhancing Connections to Develop Just-in-Time Adaptive Intervention Strategies

NCT03836391 | Completed

• 1 other identifier: 16-0775
• Study Type: interventional
• Target: 53
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this pilot study is to examine the effects of different types of just-in-time intervention messages on daily meeting dietary, activity, and weighing goals in a sample of young adults participating in a mobile-based weight loss program.

Conditions

Overweight and Obesity; Overweight; Obesity

Keywords

Mobile health; Physical activity; Nutrition; Self-monitoring; Smartphone app; Digital health tools

Outcome Measures

Primary Outcomes (6)

• Percent of person-days with same-day weighing

  Percent who weighed after the message randomization time until the end of the day (at the participant-day level) across the 12-week study

  from Baseline to Week 12

• Percent of person-days with next-day weighing

  Percent who weighed the day after the message randomization (at the participant-day level) across the 12-week study

  from Baseline to Week 12

• Percent of person-days met active minutes goal on same day

  Percent who met active minutes goal after the message randomization time until the end of the day (at the participant-day level) across the 12-week study

  from Baseline to Week 12

• Percent of person-days met active minutes goal on next day

  Percent who met active minutes goal the day after the message randomization (at the participant-day level) across the 12-week study

  from Baseline to Week 12

• Percent of person-days met red foods goal on same day

  Percent who met red foods goal after the message randomization time until the end of the day (at the participant-day level) across the 12-week study

  from Baseline to Week 12

• Percent of person-days met red foods goal on next day

  Percent who met red foods goal the day after the message randomization (at the participant-day level) across the 12-week study

  from Baseline to Week 12

Secondary Outcomes (3)

• Number of active minutes

  from Baseline to Week 12

• Proximal effect of message on total red foods today

  from Baseline to Week 12

• Mean weight change

  from Baseline to Week 12

Study Arms (1)

Nudge Intervention

EXPERIMENTAL

Each of 7 intervention message options has specific decision rules (including weighed/not weighed and progress toward daily dietary and activity goals) that make a participant eligible to receive a specific intervention type at a specific time (decision points). At each decision point (early morning, morning, midday, and evening), the system evaluates which intervention options a participant is eligible to receive, and randomly chooses one intervention option from that list. Then the participant is randomly assigned to either receive or not receive that intervention message (with a 50-50 probability).

Behavioral: Nudge

Interventions

Nudge BEHAVIORAL

Nudge is a smartphone-app-based micro-randomized trial that tests the effect of 7 intervention message types based on behavior change techniques on daily goal attainment. Participants have three daily goals: weigh daily, red foods goal, and active minutes goal.

Nudge Intervention

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age 18-35
• BMI of 25-40 kg/m²
• Not adhering to the US physical activity guidelines of at least 150 moderate-to-vigorous intensity activity minutes/week
• English-speaking and writing
• No pre-existing medical condition(s) that preclude adherence to an unsupervised exercise program, diabetes treated with insulin, history of heart attack or stroke, current treatment for cancer, or inability to walk for exercise
• Has an iPhone with iOS 11 (or willing to download it) with internet access and text messaging plan
• Has home wireless access compatible with Fitbit Aria 2 scale (802.11b/g/n)

You may not qualify if:

• Current participation in another physical activity or weight control program
• Currently pregnant, pregnant in last 6 months, or planning pregnancy in next 3 months
• Report a heart condition, chest pain during periods of activity or rest, loss of consciousness, joint or bone problems, or prescription medicine usage for blood pressure or heart condition on the Physical Activity Readiness Questionnaire (PAR-Q)
• Health or psychological diagnoses that preclude participation in a prescribed dietary and exercise program, including diagnosis of schizophrenia or bipolar disorder, hospitalization for a psychiatric diagnosis in the past year, diagnosis of alcohol or substance abuse
• Occupation requires primarily night shift work
• Owns and uses a physical activity tracker
• Moving out of area in next 4 months
• Out of town for a week or more during study period
• Not willing to attend two study visits

Sponsors & Collaborators

• University of North Carolina, Chapel Hill: lead

Study Sites (1)

Department of Health Behavior, University of North Carolina, Chapel Hill

Chapel Hill, North Carolina, 27599, United States

Location

Related Publications (1)

• Valle CG, Nezami BT, O'Shea NG, Hatley KE, Tate DF. Outcomes of a pilot microrandomized trial of just-in-time adaptive intervention messages nudging weight-related behaviors in young adults. Digit Health. 2025 Jul 6;11:20552076251353267. doi: 10.1177/20552076251353267. eCollection 2025 Jan-Dec.

  PMID: 40631347 DERIVED

MeSH Terms

Conditions

Overweight; Obesity; Motor Activity

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavior

Study Officials

• Deborah F Tate, PhD

  University of North Carolina, Chapel Hill

  PRINCIPAL INVESTIGATOR

• Carmina G Valle, PhD

  University of North Carolina, Chapel Hill

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Each participant-time point is randomized between intervention message or no intervention message

Study Record Dates

• First Submitted: February 7, 2019
• First Posted: February 11, 2019
• Study Start: February 12, 2019
• Primary Completion: September 16, 2019
• Study Completion: September 16, 2019
• Last Updated: November 13, 2019

Record last verified: 2019-11

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)