Characterization of Smartphone-related Diseases Using the Phonix Care Application

NCT07293208 | Completed

• 1 other identifier: PHX_OBS_CERGA_2022
• Study Type: observational
• Target: 171
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this observational study is to describe how adolescents and young adults use screens in their daily lives and to identify different profiles of screen use ranging from low to excessive. The study also aims to understand how screen-use behaviors relate to health, motivation, and sociodemographic factors. The main questions it aims to answer are: What are the objective and self-reported patterns of screen use (e.g., frequency of use, types of apps, daily time spent, usage periods)? Do distinct screen-use profiles emerge (low, moderate, intensive/excessive) when taking into account: Age, gender, educational track (general, technological, vocational), Parents' socioeconomic status, Health variables (sleep quality, physical activity/sedentary behavior, well-being), Cognitive and conative variables (self-regulation capacity, academic motivation)? Are excessive users characterized by specific patterns, such as intensive use of social media, video platforms, or video games combined with mood problems, sleep difficulties, or motivational issues? Do screen-use profiles vary depending on age group (middle school, high school, university) and gender? Are there mediating mechanisms explaining excessive use? Specifically: Does poor self-regulation mediate the link between screen-use intensity and well-being? Do sleep problems mediate the link between excessive nighttime use and mood disturbances (anxiety, depression)? Do academic motivation and cognitive factors mediate differences between moderate and excessive users? If groups differ, researchers will compare low-use, moderate-use, and excessive-use profiles to determine whether they show meaningful differences in health, motivation, and sociodemographic characteristics. Participants will: Install a smartphone application that passively records daily screen-use indicators (e.g., usage time, app categories, frequency of openings, time windows of use). Complete questionnaires assessing: Self-reported screen use, Sleep, physical activity, well-being, Mood variables (anxiety, depression), Self-regulation, Academic motivation, Sociodemographic factors (age, gender, parents' SES, educational track).

Conditions

Screen Time

Keywords

smartphone; problematic digital use; depression; academic motivation; young adult; adolescent; digital phenotyping

Outcome Measures

Primary Outcomes (1)

• Objective Screen Use Time (Daily Median Over Monitoring Period)

  Objective screen-use time will be measured using the PhonixDiag smartphone monitoring tool. The outcome corresponds to the median daily duration (in minutes) spent on smartphone applications across the full monitoring period. This includes all app categories and reflects real-world behavioral engagement with digital media. The measure will be used to classify participants into usage profiles (low, moderate, excessive) and to examine associations with age, gender, socioeconomic status, sleep, physical activity, well-being, self-regulation, and academic motivation.

  From enrollment to the end of treatment at 4 weeks

Secondary Outcomes (8)

• Self-Reported Screen Use (Questionnaire Score)

  1 day

• Sleep Quality (Self-Reported Index)

  7 days

• Physical Activity and Sedentary Behavior (Self-Reported Levels)

  7 days

• Well-Being (Self-Reported Score)

  1 day

• Anxiety (Self-Reported Symptom Score)

  1 day

Interventions

PhonixDiag Smartphone Monitoring Tool DEVICE

PhonixDiag is a passive smartphone-based monitoring tool designed to collect objective digital behavior indicators in real time. The tool runs in the background of the participant's smartphone and records daily screen-use patterns, including frequency of app openings, time spent on recreational applications, usage periods throughout the day, and nighttime phone activity. PhonixDiag does not modify the participant's phone use or deliver any behavioral intervention. It functions solely as a data collection system to objectively assess screen-use behaviors and identify usage profiles (low, moderate, excessive). The tool is distinct from other digital interventions because it does not provide feedback, warnings, or recommendations, and operates exclusively for passive monitoring purposes.

Also known as: PhonixDiag App

Eligibility Criteria

• Age: 12 Years - 25 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Participants were recruited from secondary schools and universities in Grenoble, France, through institutional communication channels and digital platforms. Recruitment occurred within educational settings located in various regions, allowing inclusion of adolescents and young adults enrolled in middle school, high school, or university programs.

You may qualify if:

• Own an Android smartphone
• Have at least 200 MB of storage on your smartphone
• Be in middle school, high school, or university
• Be enrolled in a school within the Grenoble academy district

You may not qualify if:

• Own an iPhone
• Participate in an interventional study in the field within the last six months
• Not sign the consent form

Sponsors & Collaborators

• Phonix Health: lead

Study Sites (1)

Université Grenoble Alpes

Saint-Martin-d'Hères, France

Location

MeSH Terms

Conditions

Depression

Condition Hierarchy (Ancestors)

Behavioral Symptoms; Behavior

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Target Duration: 1 Month
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 6, 2025
• First Posted: December 19, 2025
• Study Start: April 1, 2022
• Primary Completion: March 1, 2023
• Study Completion: March 1, 2023
• Last Updated: December 19, 2025

Record last verified: 2025-12

Locations

FR (1)