General Population (no Specific Condition or Disease)NCT07473466
Evaluation of Reminder Strategies (Emails and Text Messages) to Increase Participation in the Le French Gut E-cohort
A study testing 3 standard email reminders, 3 institutional email reminders and 3 SMS reminders in people with General Population (no Specific Condition or Disease), run by SKEZI at 1 site in France.
Trial summary
This study is a randomized controlled trial nested in the "Le French Gut" e-cohort aiming to test the efficacy of 4 reminder strategies (emails and/or SMS with standard and/or institutional wording) in increasing participation of inactive volunteers. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- General Population (no Specific Condition or Disease)
- What is being tested?
- 3 standard email reminders, 3 institutional email reminders and 3 SMS reminders
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20,487 participants
- Where
- 1 siteFrance
- Study dates
- 7 Nov 2024to 25 Nov 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Being registered on the "Le French Gut" platform but not active participant (e.i. eligibility questionnaire not completed, "Le French Gut" consent not validated, "A propos de vous" questionnaire not completed)
- Having provided a valid email address and/or mobile-phone number
Who cannot join
- Completed "A propos de vous" questionnaire before the first reminder
- Being non eligible to the "Le French Gut" cohort (eligibility to "Le Fench Gut" cohort: being over 18 years-old and living in France)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Le French Gut: Randomized-Controlled Trial to Evaluate Reminder Strategies (Emails and Text Messages) to Increase Participation in the Le French Gut E-cohort
This study is a randomized controlled trial nested in the "Le French Gut" e-cohort aiming to test the efficacy of 4 reminder strategies (emails and/or SMS with standard and/or institutional wording) in increasing participation of inactive volunteers.
This trial is led in collaboration between the "Le French Gut" project and SKEZI, a DeepTech start-up which markets the data collection solution (SKEZIA online platform) for the "Le French Gut" project and carries out the InnoPRO program, aimed at generating new knowledge in the field of e-cohorts.
Read the detailed description
The "Le French Gut" project (NCT05758961) is an ongoing online research cohort aiming to collect faecal samples and associated nutritional and clinical data to better understand the observed heterogeneity between gut microbiome of healthy subjects, its connections with the diet and lifestyle, but also changes in gut microbiota associated with diseases (diabetes, obesity, allergies, cancer, Parkinson, Alzheimer…). Le French Gut is initiated by MetaGenoPolis-INRAE, supported by INRAE with Prof. R. Benamouzig, (AP-HP) as principal investigator of the project.
When participants first register to participate in the cohort, they must complete a short "About You" ("A propos de vous") questionnaire before they can receive any study kits and be considered as active participants in the research. In October 2024, almost half of the ~43,000 individuals who have created an account never finish this first questionnaire needed to validate their participation in the cohort.
Purpose of the study This study will test which type of reminder works best for encouraging those inactive volunteers to return to the platform and complete the missing questionnaire.
How the study will be done
All eligible volunteers (i.e. people who registered on the online platform and provided a valid e mail address or mobile number but have not yet finished completing the "A propos de vous" questionnaire) will be randomly assigned to one of four groups:
- Standard e mail - a regular, semi-formal email. Same email sent three times, 72h apart.
- SMS - a short text message sent to the participant's phone. Same SMS sent three times, 72h apart.
- Institutional e mail - a plain, formal email signed by the "Le French Gut" study coordinator. Same email sent three times, 72h apart.
- Combined sequence - a standard e mail, followed 72 hours later by the SMS, and 72 hours after that by the institutional e mail.
All messages contain the same content (a link that takes the participant directly to the questionnaire). The study will last about one month after the last reminder is sent.
Questions the study will answer
- Which reminder method results in the highest completion rate of the "A propos de vous" questionnaire (i.e. proportion of people completing the questionnaire) within 30 days?
- How quickly do participants respond after each type of reminder?
- Does the time since a person first registered (recent vs. long time registrant) influence which reminder works best?
Hypothesis Investigators hypothesized that the combined sequence (standard e mail → SMS → institutional e mail) will lead to a higher proportion of participants completing the questionnaire than any single channel reminder alone.
Why this matters Finding the most effective, low cost reminder strategy will help the French Gut team-and other online cohorts-keep more participants engaged, thereby improving the quantity and quality of the data that can be used for future health research. The results will be shared in a peer reviewed scientific article and could guide the design of future e cohort studies worldwide.
- Being tested
- 3 standard email reminders, 3 institutional email reminders, 3 SMS reminders, Combined reminders
- Keywords
- e-cohort, reminder strategy, response rate, email reminder, text message reminder, completion, inclusion
- Medical subject headings
- Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
3 standard email remindersOther
The same standard email is sent three times to participants, each email spaced 72 hours apart.
3 institutional email remindersOther
The same institutional email is sent three times to participants, each email spaced 72 hours apart.
3 SMS remindersOther
The same SMS (brief text message) is sent three times to participants, each SMS spaced 72 hours apart.
Combined remindersOther
Three reminders are sent to participants, each reminder spaced 72 hours apart: the first reminder is a standard email, the second reminder is a SMS, the third reminder is a institutional email.
| Study group | Role | What they receive |
|---|---|---|
| standard emails only | Experimental | Standard, semi-formal worded email inviting participants to complete the online "A propos de vous" (personal information) questionnaire in order to validate their participation in the "Le French Gut" cohort. Receives: Other: 3 standard email reminders |
| institutional emails only | Experimental | Institutional, formal-worded email, signed by the study coordinator, inviting participants to complete the online "A propos de vous" (personal information) questionnaire in order to validate their participation in the "Le French Gut" cohort. Receives: Other: 3 institutional email reminders |
| SMS only | Experimental | Short text message inviting participants to complete the online "A propos de vous" (personal information) questionnaire in order to validate their participation in the "Le French Gut" cohort. Receives: Other: 3 SMS reminders |
| Combined reminders | Experimental | Combined sequence of reminders: first, the standard email; second, the SMS; third, the institutional email. The contents of the reminders are similar to those of the three other parallel groups inviting participants to complete the online "A propos de vous" (personal information) questionnaire in order to validate their participation in the "Le French Gut" cohort. Receives: Other: Combined reminders |
What is being measured
The primary outcome is the main question the study is designed to answer.
Completion rate
Proportion of participants who complete the "A propos de vous" questionnaire within 30 days after the last reminder, calculated as number of participants who fully completed the questionnaire divided by total number of participants included in the study (or arm)
Measured: 30 days post-reminder
Secondary outcomes (3)
Completion time
Time (in hours) between the date the last reminder was sent to a participant and the date of questionnaire completion
Measured: 30 days post-reminder
Login rate
Number of participants who logged into their account divided by total number of participants included in the study (or arm)
Measured: 30 days post-reminder
Login time
Time (in hours) between the date the final reminder was sent to a participant and the date of their next login to the platform
Measured: 30 days post-reminder
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Mar 2026
- Study start7 Nov 2024
- Primary completion25 Nov 2024
- Study completion25 Nov 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for General Population (no Specific Condition or Disease)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized, parallel groups, 4-arm, 1:1:1:1 allocation ratio, stratified (by time-since-registration: : ≤ 6 months, 6-12 months, 12-18 months, \>18 months), blinded (data analyst blind to allocation and participants unaware of the trial being conducted)
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 20,487 participants (actual)
Sponsor and investigators
- Lead sponsor
- SKEZI
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
- Responsible party
- Principal investigator, Jean-Philippe BERTOCCHIO, SKEZI
- Investigators
- Jean-Philippe Bertocchio, MD, PhD, Principal investigator, SKEZI
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07473466
- Sponsor's protocol ID
- LFGxSKEZI-2024-001
- Status last verified
- Mar 2026
- First submitted
- 11 Mar 2026
- Last updated
- 17 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Le French Gut: Randomized-Controlled Trial to Evaluate Reminder Strategies (Emails and Text Messages) to Increase Participation in the Le French Gut E-cohort
- ClinicalTrials.gov ID
- NCT07473466
- Acronym / sponsor ID
- LFGxSKEZI-2024-001
- Keywords
- e-cohort, reminder strategy, response rate, email reminder, text message reminder, completion, inclusion
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20,487 participants (actual)
- Lead sponsor
- SKEZIIndustry (pharma, biotech, devices)
- Collaborators
- Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
- Study start
- 7 Nov 2024 (actual)
- Primary completion
- 25 Nov 2024 (actual)
- Study completion
- 25 Nov 2024 (actual)
- First posted
- 16 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is a randomized controlled trial nested in the "Le French Gut" e-cohort aiming to test the efficacy of 4 reminder strategies (emails and/or SMS with standard and/or institutional wording) in increasing participation of inactive volunteers.
This trial is led in collaboration between the "Le French Gut" project and SKEZI, a DeepTech start-up which markets the data collection solution (SKEZIA online platform) for the "Le French Gut" project and carries out the InnoPRO program, aimed at generating new knowledge in the field of e-cohorts.
Detailed description
The "Le French Gut" project (NCT05758961) is an ongoing online research cohort aiming to collect faecal samples and associated nutritional and clinical data to better understand the observed heterogeneity between gut microbiome of healthy subjects, its connections with the diet and lifestyle, but also changes in gut microbiota associated with diseases (diabetes, obesity, allergies, cancer, Parkinson, Alzheimer…). Le French Gut is initiated by MetaGenoPolis-INRAE, supported by INRAE with Prof. R. Benamouzig, (AP-HP) as principal investigator of the project.
When participants first register to participate in the cohort, they must complete a short "About You" ("A propos de vous") questionnaire before they can receive any study kits and be considered as active participants in the research. In October 2024, almost half of the ~43,000 individuals who have created an account never finish this first questionnaire needed to validate their participation in the cohort.
Purpose of the study This study will test which type of reminder works best for encouraging those inactive volunteers to return to the platform and complete the missing questionnaire.
How the study will be done
All eligible volunteers (i.e. people who registered on the online platform and provided a valid e mail address or mobile number but have not yet finished completing the "A propos de vous" questionnaire) will be randomly assigned to one of four groups:
- Standard e mail - a regular, semi-formal email. Same email sent three times, 72h apart.
- SMS - a short text message sent to the participant's phone. Same SMS sent three times, 72h apart.
- Institutional e mail - a plain, formal email signed by the "Le French Gut" study coordinator. Same email sent three times, 72h apart.
- Combined sequence - a standard e mail, followed 72 hours later by the SMS, and 72 hours after that by the institutional e mail.
All messages contain the same content (a link that takes the participant directly to the questionnaire). The study will last about one month after the last reminder is sent.
Questions the study will answer
- Which reminder method results in the highest completion rate of the "A propos de vous" questionnaire (i.e. proportion of people completing the questionnaire) within 30 days?
- How quickly do participants respond after each type of reminder?
- Does the time since a person first registered (recent vs. long time registrant) influence which reminder works best?
Hypothesis Investigators hypothesized that the combined sequence (standard e mail → SMS → institutional e mail) will lead to a higher proportion of participants completing the questionnaire than any single channel reminder alone.
Why this matters Finding the most effective, low cost reminder strategy will help the French Gut team-and other online cohorts-keep more participants engaged, thereby improving the quantity and quality of the data that can be used for future health research. The results will be shared in a peer reviewed scientific article and could guide the design of future e cohort studies worldwide.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 4
- Model description
- Randomized, parallel groups, 4-arm, 1:1:1:1 allocation ratio, stratified (by time-since-registration: : ≤ 6 months, 6-12 months, 12-18 months, >18 months), blinded (data analyst blind to allocation and participants unaware of the trial being conducted)
| Arm | Type | Receives |
|---|---|---|
| standard emails only | Experimental | Other: 3 standard email remindersStandard, semi-formal worded email inviting participants to complete the online "A propos de vous" (personal information) questionnaire in order to validate their participation in the "Le French Gut" cohort. |
| institutional emails only | Experimental | Other: 3 institutional email remindersInstitutional, formal-worded email, signed by the study coordinator, inviting participants to complete the online "A propos de vous" (personal information) questionnaire in order to validate their participation in the "Le French Gut" cohort. |
| SMS only | Experimental | Other: 3 SMS remindersShort text message inviting participants to complete the online "A propos de vous" (personal information) questionnaire in order to validate their participation in the "Le French Gut" cohort. |
| Combined reminders | Experimental | Other: Combined remindersCombined sequence of reminders: first, the standard email; second, the SMS; third, the institutional email. The contents of the reminders are similar to those of the three other parallel groups inviting participants to complete the online "A propos de vous" (personal information) questionnaire in order to validate their participation in the "Le French Gut" cohort. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Being registered on the "Le French Gut" platform but not active participant (e.i. eligibility questionnaire not completed, "Le French Gut" consent not validated, "A propos de vous" questionnaire not completed)
- Having provided a valid email address and/or mobile-phone number
Key exclusion criteria (2 listed)
- Completed "A propos de vous" questionnaire before the first reminder
- Being non eligible to the "Le French Gut" cohort (eligibility to "Le Fench Gut" cohort: being over 18 years-old and living in France)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 3 standard email remindersThe same standard email is sent three times to participants, each email spaced 72 hours apart. | Other | standard emails only |
| 3 institutional email remindersThe same institutional email is sent three times to participants, each email spaced 72 hours apart. | Other | institutional emails only |
| 3 SMS remindersThe same SMS (brief text message) is sent three times to participants, each SMS spaced 72 hours apart. | Other | SMS only |
| Combined remindersThree reminders are sent to participants, each reminder spaced 72 hours apart: the first reminder is a standard email, the second reminder is a SMS, the third reminder is a institutional email. | Other | Combined reminders |
Primary outcome
Completion rate
Time frame: 30 days post-reminder
Proportion of participants who complete the "A propos de vous" questionnaire within 30 days after the last reminder, calculated as number of participants who fully completed the questionnaire divided by total number of participants included in the study (or arm)
3 secondary outcomes
Completion time
Time frame: 30 days post-reminder
Login rate
Time frame: 30 days post-reminder
Login time
Time frame: 30 days post-reminder
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Mar 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jean-Philippe Bertocchio, MD, PhD principal investigator
SKEZI
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 3 standard email reminders, 3 institutional email reminders and 3 SMS reminders in people with General Population (no Specific Condition or Disease), run by SKEZI at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 17 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Completion rate (time frame: 30 days post-reminder). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Mar 2026.