Impact of Dietary Knowledge Related to Functional Insulin Therapy in Type 1 Diabetes on the Risk of Eating Disorders

STUDY DESCRIPTION

This is a Type 3 study under the Jardé law, involving human subjects:

Observational study Prospective design Monocentric National scope

We selected this study design to minimize participant burden (data collection conducted online, by phone, or via videoconference, eliminating the need for patient travel). Recruitment through patient association websites and social media will enable a national reach.

The study will take place in four phases:

Recruitment Videoconference for a questionnaire on FIT-related dietary knowledge and ED risk assessment Self-administered online questionnaire Videoconference interview

SELECTION AND INCLUSION VISIT

If the participant wishes to join the study, they can either scan the QR code or visit the web link provided in the recruitment announcement. This QR code or link will redirect to a page detailing the study, the eligibility criteria that the participant must complete, and the information notice. The participant will enter their email address in the designated field and will also have the option to download the information notice if they wish.

Once this step is completed, the principal investigator will verify the eligibility criteria. If the participant meets the criteria, they will receive an email containing the necessary information for the next steps of the study:

Non-opposition letter - Part 1 A personal identifier number (formatted as initials + number, e.g., LA01) to pseudonymize questionnaire and self-reported responses A calendar allowing them to indicate their preferred date for the videoconference A link to access the videoconference

To ensure that the participant fully understands the study procedures, the clinical research associate (CRA) will go over the project details during the first videoconference and address any questions. The CRA will also check that the non-opposition form has been properly completed before integrating it into the study records.

If the participant does not meet the eligibility criteria, they will receive an email notifying them of their ineligibility.

The principal investigator will maintain a correspondence table containing the participant's name, surname, email address, and personal identifier number.

Participants will be fully and transparently informed in clear and understandable terms about the study objectives, the nature of the collected data, and their right to withdraw their consent at any time. The investigator must also inform participants about the opinion issued by the Ethics Committee (Comité de Protection des Personnes - CPP).

Participants can exercise their right to oppose the processing of their health data for research purposes at any time by contacting either the research coordinator or the institution responsible for the data. The institution is committed to responding to such requests within a maximum of two months.

FOLLOW-UP VISITS

The study will be conducted in three distinct phases:

• First Phase: Videoconference for Questionnaire Completion

A clinical research associate (CRA) will contact the participant to administer the questionnaires. The CRA will directly enter the participant's responses into the Redcap online platform.

At the end of this interview, the investigator will invite participants to take part in the qualitative phase of the study (third phase: semi-structured videoconference interview). Participants will be progressively included until data saturation is reached.

If the participant agrees, the investigator will send a second email with a second non-opposition form - Part 2 (Appendix 4) for participation in the qualitative interview.

For all participants, a Redcap platform link will be emailed to them to complete the self-reported questionnaires.

• Second Phase: Online Self-Questionnaires

Participants will receive a link to complete self-administered questionnaires directly on Redcap. Contact information for the CRA or investigator will be provided in case of technical issues.

• Third Phase: Semi-Structured Videoconference Interview

This interview will be semi-structured and will follow the interview guide provided in Appendix 12. Participants will be included in this phase until data saturation is reached.

For the first and third phases, we have chosen to conduct interviews via the BigBlueButton videoconferencing platform, which is GDPR-compliant. We aim to use a platform that is user-friendly and free for participants.

Since BigBlueButton is integrated with the Université Grenoble Alpes information system, no additional identification data will be processed. The following personal data-voice and image-will be recorded by the interview organizer.

If the recording feature is activated, participants will be explicitly notified via a specific message. The recordings will be used exclusively for the transcription of data.

Inclusion criteria

• Diagnosis of type 1 diabetes confirmed by a referring physician
• Diagnosis received at least three months prior
• Adult (18 years or older)
• Access to a computer or smartphone capable of videoconferencing
• No expressed opposition to participation
• Consent for image rights (for Phase 2 qualitative interviews)

Exclusion criteria

• Inability to complete online questionnaires and participate in a 45-minute videoconference interview
• Being under legal guardianship or curatorship
• Being pregnant or breastfeeding