Effects of Digital Health Interventions on the Physical and Mental Health of Middle School Students

1. Study Population

1. Sample Size: 20 classes, about 800-1000 children.
2. Randomization: This study will adopt a cluster-randomized controlled intervention design. 20 Classes will be randomly assigned in a 1:1:1:1 ratio to one of four groups: the graphic-text intervention group, the video intervention group, the AI dialogue intervention group, and the control group. The randomization process will be centralized and conducted by personnel not involved in the project.

3. Inclusion Criteria (all of the following must be met for inclusion):

   Both children/adolescents and their parents are willing to participate and demonstrate good compliance.

   Children/adolescents have a weight classified as normal, overweight, or obese. Age range: 11 to 13 years. Informed consent is obtained from both the child and the parent.

4. Exclusion Criteria (meeting any one of the following will result in exclusion):

Clinically diagnosed severe mental illness or psychiatric disorders. Clinically diagnosed eating disorders (e.g., binge eating disorder). Physical developmental abnormalities or disabilities that prevent normal physical activity.

Study Overview

• Status: Active, not recruiting
• Conditions: Pediatric Obesity
• Intervention / Treatment: Other: Graphic-text Intervention; Other: Video Intervention; Other: AI Dialogue Intervention

Detailed Description

Intervention Content Control Group: The students did not receive any additional intervention and continued with their regular school activities. After the intervention, a complete set of video and graphic materials was provided to the control group students to ensure ethical fairness.

Graphic-text Intervention Group: The students read the electronic version of the instruction manual on the computer screen in the computer room for about 10 minutes each week.

Video Intervention Group: Students watch AI-produced videos on the computer screens in the computer room for about 10 minutes each week. The playback progress of the videos is uniformly controlled by the teacher end, and the student end cannot operate it independently.

AI Dialogue Intervention Group: Students conducted text-based conversations with a "health partner" based on a large language model using computers in the computer room, for approximately 10-15 minutes each week. In this group, about half of the students were randomly assigned to the motivational interview dialogue group, while the other half were assigned to the non-motivational interview dialogue group. The content of the conversations (all focusing on topics related to physical activity) and the duration of the conversations were the same for both groups, but the communication methods were different.

Follow-up Survey This study will conduct assessments at baseline (1 week before the intervention), 1 week after the end of the intervention, and 8 weeks after the end of the intervention. Baseline assessment will include all outcome measures, demographic information, and baseline physical activity level. The assessment at 1 week after the intervention will include all outcome measures, process indicators, and satisfaction evaluation (for intervention groups only). The assessment at 8 weeks after the intervention will include all outcome measures and behavioral maintenance. In addition, for the AI dialogue group, an immediate post-test will be conducted after the first dialogue session, and an additional follow-up assessment will be conducted during the mid-intervention period (approximately 1-2 weeks after baseline).

• Study Type: Interventional
• Enrollment (Estimated): 800
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Hebei
    • Tangshan, Hebei, China, 064300
      • Qianxi County No. 3 Middle School

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

1. Inclusion Criteria (all of the following must be met for inclusion):

   Both children/adolescents and their parents are willing to participate and demonstrate good compliance.

   Children/adolescents have a weight classified as normal, overweight, or obese. Age range: 11 to 13 years. Informed consent is obtained from both the child and the parent.

2. Exclusion Criteria (meeting any one of the following will result in exclusion):

Clinically diagnosed severe mental illness or psychiatric disorders. Clinically diagnosed eating disorders (e.g., binge eating disorder). Physical developmental abnormalities or disabilities that prevent normal physical activity.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Graphic-text Intervention Group; The students read the electronic version of the instruction manual on the computer screen in the computer room for about 10 minutes each week.	Other: Graphic-text Intervention; The students read the electronic version of the instruction manual on the computer screen in the computer room for about 10 minutes each week.
Experimental: Video Intervention Group; Students watch AI-produced videos on the computer screens in the computer room for about 10 minutes each week. The playback progress of the videos is uniformly controlled by the teacher end, and the student end cannot operate it independently.	Other: Video Intervention; Students watch AI-produced videos on the computer screens in the computer room for about 10 minutes each week. The playback progress of the videos is uniformly controlled by the teacher end, and the student end cannot operate it independently.
Experimental: AI Dialogue Intervention Group; Students conducted text-based conversations with a "health partner" based on a large language model using computers in the computer room, for approximately 10-15 minutes each week. In this group, about half of the students were randomly assigned to the motivational interview dialogue group, while the other half were assigned to the non-motivational interview dialogue group. The content of the conversations (all focusing on topics related to physical activity) and the duration of the conversations were the same for both groups, but the communication methods were different.	Other: AI Dialogue Intervention; Students conducted text-based conversations with a "health partner" based on a large language model using computers in the computer room, for approximately 10-15 minutes each week. In this group, about half of the students were randomly assigned to the motivational interview dialogue group, while the other half were assigned to the non-motivational interview dialogue group. The content of the conversations (all focusing on topics related to physical activity) and the duration of the conversations were the same for both groups, but the communication methods were different.
No Intervention: Control Group; The students did not receive any additional intervention and continued with their regular school activities. After the intervention, a complete set of video and graphic materials was provided to the control group students to ensure ethical fairness.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Depressive Symptoms	Depressive symptoms will be assessed using the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10), with higher scores indicating more severe depressive symptoms.	Baseline (1 week before the intervention), 1 week after the end of the intervention, and 8 weeks after the end of the intervention.
Anxiety Symptoms	Anxiety symptoms will be assessed using the 7-item Generalized Anxiety Disorder scale (GAD-7), with higher scores indicating more severe anxiety symptoms.	Baseline (1 week before the intervention), 1 week after the end of the intervention, and 8 weeks after the end of the intervention.
Behavior Change Motivation	Behavior change motivation will be assessed using a study questionnaire measuring participants' motivation to initiate and sustain target health behavior change.	Baseline (1 week before the intervention), the very end of the intervention, and 8 weeks after the end of the intervention.
Autonomous Motivation	Autonomous motivation will be assessed using a study questionnaire to measure the extent to which participants engage in the target behavior for self-endorsed and personally valued reasons.	Baseline (1 week before the intervention), 1 week after the end of the intervention, 1 month after the end of the intervention, and 8 weeks after the end of the intervention.
Physical Activity Level	Physical activity level will be assessed using the questionnaire, which captures self-reported physical activity. This outcome will be assessed in the graphic-text intervention and AI dialogue intervention groups and the control group only.	Baseline (1 week before the intervention), 1 week after the end of the intervention, 1 month after the end of the intervention, and 8 weeks after the end of the intervention.
Exercise Self-Efficacy	Exercise self-efficacy will be assessed using a study questionnaire measuring participants' confidence in their ability to engage in and maintain physical activity under various circumstances.	Baseline (1 week before the intervention), 1 week after the end of the intervention, 1 month after the end of the intervention, and 8 weeks after the end of the intervention.
Stage of Behavior Change	Stage of behavior change will be assessed using a study questionnaire, measuring participants' behavior change stages with respect to the target behavior.	Baseline (1 week before the intervention), 1 month after the end of the intervention, and 8 weeks after the end of the intervention.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Emotion Regulation Ability	Emotion regulation ability will be assessed using the Emotion Regulation Questionnaire (ERQ), which measures individuals' habitual use of cognitive reappraisal and expressive suppression strategies.	Baseline (1 week before the intervention), 1 week after the end of the intervention, and 8 weeks after the end of the intervention.
Psychological Resilience	Psychological resilience will be assessed using the 10-item Connor-Davidson Resilience Scale (CD-RISC-10).	Baseline (1 week before the intervention), 1 week after the end of the intervention, and 8 weeks after the end of the intervention.
Help-Seeking Intention	Help-seeking intention will be assessed using the adapted version of the General Help-Seeking Questionnaire (GHSQ), which measures participants' intentions to seek help from formal and informal sources for emotional or psychological problems.	Baseline (1 week before the intervention), 1 week after the end of the intervention, and 8 weeks after the end of the intervention.
Social Support Network	Social support network will be assessed using the name generator method to characterize the availability and structure of participants' perceived social support network.	Baseline (1 week before the intervention), 1 week after the end of the intervention, and 8 weeks after the end of the intervention.
Human-AI Relationship	Human-AI relationship will be assessed using a study questionnaire measuring participants' perceived relationship with the AI system. This outcome will be assessed only in the AI dialogue intervention group.	the very end of the intervention
Quality of Motivational Interviewing	The quality of motivational interviewing will be assessed using study questionnaire measuring participants' perceived quality of AI-delivered motivational interviewing. This outcome will be assessed only in the AI dialogue intervention group.	the very end of the intervention

Collaborators and Investigators

• Sponsor: Peking University

Study record dates

Study Major Dates

• Study Start (Actual): May 12, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): January 1, 2027

Study Registration Dates

• First Submitted: August 4, 2024
• First Submitted That Met QC Criteria: August 7, 2024
• First Posted (Actual): August 9, 2024

Study Record Updates

• Last Update Posted (Actual): May 28, 2026
• Last Update Submitted That Met QC Criteria: May 24, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Obesity; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Pediatric Obesity
• Other Study ID Numbers: PU IRB V1 (2023-10-31)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No