Piloting a Reinforcement Learning Tool for Individually Tailoring Just-in-time Adaptive Interventions

NCT ID: NCT05751993

Last Updated: 2025-08-24

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 19 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-04-12
• Study Completion Date: 2025-08-18

Brief Summary

The purpose of this pilot study is to conduct a 12-week pilot feasibility study testing usability of a reinforcement learning model (AdaptRL) in a weight loss intervention (ADAPT study). Building upon a previous just-in-time adaptive intervention (JITAI), a reinforcement learning model will generate decision rules unique to each individual that are intended to improve the tailoring of brief intervention messages (e.g., what behavior to message about, what behavior change techniques to include), improve achievement of daily behavioral goals, and improve weight loss in a sample of 20 adults.

Detailed Description

Reinforcement Learning (RL), a type of machine learning, holds promise for addressing the limitations of previous approaches to implementing JITAIs. Adaptive RL applications work by updating information about expected "rewards" (i.e., proximal outcomes) based on the results of sequentially randomized trials. To realize the potential of adaptive interventions to reduce health disparities in cancer prevention and control, mHealth interventionists first need to identify methods of using digital health participant data to continually adapt decision rules guiding highly tailored intervention delivery. This research team has developed a reinforcement learning model (AdaptRL) that reads in and analyzes user data (e.g., calories, weight, and activity data from Fitbit) in real-time, uses RL to efficiently determine which message a participant should receive up to 3 times per day, and creates a JITAI tailored to optimize daily behavioral goal achievement and weight loss for each participant. The objective of this study is to test the feasibility of using this reinforcement learning model in a pilot weight loss study.

Conditions

Overweight and Obesity; Overweight; Obesity

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: HEALTH_SERVICES_RESEARCH
• Blinding Strategy: NONE

Study Groups

ADAPT intervention

Participants will receive a smart scale and a physical activity tracker and will have three daily goals: weigh daily, a daily personalized active minutes goal, and a daily calorie goal. For 12 weeks, participants will receive 0-3 text messages per day about their behaviors and progress towards their goals, along with weekly personalized feedback, progress graphs, and lessons and resources available on the website.

Group Type: EXPERIMENTAL

ADAPT

Intervention Type: BEHAVIORAL

The intervention is testing the feasibility of a reinforcement learning model to pull in participants' behavioral data (calories, activity, and weight) and use this data along with participants' past behavioral goal achievements to deliver the type of message that should be most effective for a given participant at a given time. At each decision point (morning, midday, and evening on a daily basis), the system evaluates which behaviors a participant is eligible to receive a message about (eating, activity, self-weighing), which intervention options a participant is eligible to receive, and then chooses what type of behavioral message a participant should receive. Over time, the model uses participant data and response to interventions to better tailor message choice.

Interventions

ADAPT

The intervention is testing the feasibility of a reinforcement learning model to pull in participants' behavioral data (calories, activity, and weight) and use this data along with participants' past behavioral goal achievements to deliver the type of message that should be most effective for a given participant at a given time. At each decision point (morning, midday, and evening on a daily basis), the system evaluates which behaviors a participant is eligible to receive a message about (eating, activity, self-weighing), which intervention options a participant is eligible to receive, and then chooses what type of behavioral message a participant should receive. Over time, the model uses participant data and response to interventions to better tailor message choice.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

1. Age 18-55 years

2. Body Mass Index of 25-40 kg/m2

3. English-speaking and writing

4. Has a smartphone with a data and text messaging plan

Exclusion Criteria

1. Currently participating in a weight loss, nutrition, or physical activity study or program or other study that would interfere with this study

2. Currently using prescription medications with known effects on appetite or weight (e.g., oral steroids, weight loss medications), with the exception of individuals on a stable dose of SSRIs for 3 months)

3. Previous surgical procedure for weight loss or planned weight loss surgery in the next year

4. Currently pregnant or planning pregnancy in the next 4 months

5. Lost 10 or more pounds and kept it off in the last 6 months

6. Report a heart condition, chest pain during periods of activity or rest, or loss of consciousness on the Physical Activity Readiness Questionnaire (PAR-Q; items 1-4). Individuals endorsing joint problems, prescription medication usage, or other medical conditions that could limit exercise will be required to obtain written physician consent to participate

7. 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

8. Type 1 diabetes or currently receiving medical treatment for Type 2 diabetes

9. Other health problems which may influence the ability to walk for physical activity or be associated with unintentional weight change, including cancer treatment within the past 5 years or tuberculosis

10. Health or psychological diagnoses that preclude participation in a prescribed dietary and exercise program, including history of or diagnosis of schizophrenia or bipolar disorder, hospitalization for a psychiatric diagnosis in the past year, a current diagnosis of alcohol or substance abuse

11. Report a past diagnosis of or receiving treatment for a DSM-5-TR eating disorder (anorexia nervosa, bulimia nervosa, or other diagnosis)

12. Another member of the household is a participant or staff member in this trial

13. Not willing to attend one study visit

14. Not willing to wear a Fitbit every day

15. Reason to suspect that the participant would not adhere to the study intervention

16. Have participated in another study conducted by the UNC Weight Research Program within the past 12 months

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

RTI International

OTHER

Sponsor Role: collaborator

National Cancer Institute (NCI)

NIH

Sponsor Role: collaborator

UNC Lineberger Comprehensive Cancer Center

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Brooke Nezami, PhD, MA

Role: PRINCIPAL_INVESTIGATOR

University of North Carolina, Chapel Hill

Locations

University of North Carolina at Chapel Hill

Chapel Hill, North Carolina, United States

Countries

United States

Related Links

http://unclineberger.org/patientcare/clinical-trials/clinical-trials

University of North Carolina Lineberger Comprehensive Cancer Center Clinical Trials

Other Identifiers

R21CA260092

Identifier Type: NIH

Identifier Source: secondary_id

View Link

22-0149

Identifier Type: -

Identifier Source: org_study_id