The Seafarers' Continuous Glucose Monitoring Systems Study

STUDY DESIGN and METHODS of DATA COLLECTION AND DATA ANALYSIS This will be an observational and feasibility study on the use of the insulin-treated fisher seafarers' with or without own real-time CGM systems, such as Dexcom G6®, Dexcom G7®, Guardian 4 or Abbott Freestyle Libre. The participating seafaers with insulin-treated diabetes who are currently monitoring their glucose levels using a CGM and certified to undertake commercial work at sea and will be taking corrective actions according to their glucose readings. The CE marked Dexcom G7® will be provided to the participants in the study for 1 year. A questionnaire is designed to streamline the process of the glucose management while at sea. Additionally, a progressive web app (Fishers Watch) will be provided and accessible by participants via their own smartphone devices to enable better recording of adverse/diabetes-related events and activities during the study and can also help indicate their on- and off-duty periods to facilitate data analysis.

Participants will be encouraged to use their CGM glucose measurement data from their own devices, to assist with their diabetes management. The involvement of the participants in the study will be 12 months. The participants will be reminded during the study that it is crucial to log their CGM glucose measurements alongside their activities and any hypoglycaemic/hyperglycaemic episodes within this timeframe.

Screening/run-in period Seafarers will be recruited via the MCA ML5 or ENG1 medical certification processes for medical certification (see Appendix 2). All insulin treated seafarers who presenting for an ML5 or ENG1 certificate who are assessed as fit to work at sea will be asked for and will be provided with information and a consent form for the Scheme6 (Appendix 3). All signed consent forms confirming to be approached by the investigators at the University of Surrey, will be forwarded to the investigators at the University of Surrey. We, the investigators at Surrey, will then have the email contact for the seafarer and we can then approach the interested seafarers directly (Appendix 1 Supplementary Material 2).

Screening visit (Virtual visit 1)

All seafarer will be invited for a virtual/online/phone screening visit. The virtual meetings will be held on TEAMs.

Before screening takes place, participants (seafarers) will be provided with verbal and written information about the trial and the procedures involved in a virtual visit with prior appointment. They will be fully informed of their responsibilities and rights while participating in this exploratory trial. They will be given the opportunity to ask questions and ample time to consider participation. Participants who wish to participate in the trial will be required to sign and date an Informed Consent Form prior to any trial-related activities taking place. All participants will be provided with a copy of fully signed and dated Informed Consent Form.

The following information will be recorded from the annual diabetes clinic visit at the GP: health data: medical history, concomitant medication, and HbA1c results and DOB, age, tobacco smoking status, alcohol intake. The subject will be asked to share the data with the PIs in the study for the clinical report files (CRF) files. If the participant fulfils all inclusion criteria and none of the exclusion criteria they will be accepted into the study.

Visit 1 On TEAMs:

Following screening, seafarers who are eligible for the study will be recruited in this virtual visit on TEAMs by the University of Surrey investigators. The participants will be informed that they will be required to monitor their glucose levels using their own the study CGM device at all times during the next 12 months of the study and make their electronic glucose records available to the research team through the Dexcom Clarity platform. The participants will be asked to record any out-of-range glucose measurements and any events or consequences when they are at sea. This data will be collected using a dedicated progressive web-app designed for this study (Fishers Watch web-app). The participants will also record the dates they at sea at sea and when working at sea or at rest.

A questionnaire will be distributed to all eligible participants to ensure the proposed usage of devices will be compatible with their work activities while at sea. This questionnaire will be used to evaluate the impact of this study on their work and to inform on further changes to the protocol as necessary.

The participants will be supplied with Dexcom G7® CGM sensors sufficient for the next 6months. The supplies will be sent by post.

Virtual Visit 2 on TEAMs: This will take place months after virtual visit 1 (3 months±7 days).

Participants are reviewed virtually/online on TEAMs at 3 months. They will be asked if they are willing to continue with the study participation. If they decide not to take part, we will let the Medical team at the MCA agency know of their decision. The adverse events and concomitant medications will be reviewed and recorded: The data from their study CGM will be reviewed and collected from Dexcom Clarity platform. The events and activities recorded by the participants' in the Fishers Watch App between visit 1 and visit 2 will also be collected.

As in virtual visit 1, the participants will be asked to record any out-of-range glucose measurements and any events or consequences when they are at sea. This data will be collected using the Fishers Watch App for the period between virtual visit 2-visit 3.

Virtual Visit 3 on TEAMs: This will take place 6 months after visit 1 (6 months±7 days).

Participants are reviewed virtually/online on TEAMs at 6 months. They will be asked if they are willing to continue with the study participation. If they decide not to take part we will let the Medical team at the MCA agency know of their decision. The following will be reviewed and recorded: adverse event, concomitant medication. The data from their study CGM will be reviewed and collected from Dexcom Clarity platform. The events and activities recorded in the participants' Fishers Watch App between visit 2 and visit 3 will also be collected.

As in visit 2, the participants will be asked to collect the data from their CGM in the study Fishers Watch App for the period between virtual visit 3-visit 4.

The participants will be supplied with Dexcom G7® CGM sensors sufficient for the next 6months. The supplies will be sent by post.

Visit 4 (End study): This will take place 12 months after visit 1 (12 months ± 7 days).

Participants will be asked to attend the virtual appointment 6 months after visit 3. They will be asked if they are willing to continue with the study participation. The following will be reviewed and recorded: adverse event, concomitant medication, HbA1c required for the annual diabetes clinic at the GP. The data from their CGMS will be collected and reviewed from Dexcom Clarity platform. The events and activities recorded in the participants' the Fishers Watch App between virtual visit 3 and visit 4 will also be collected.

Measurements (recordings):

Virtual Visits 1 and Visit 4 Participant's HbA1c measurements will be retrieved from their most recent medical records at Visit 1 and Visit 4.

CGM Data collection:

Virtual Visits 1, Visit2, Visit 3 and Visit 4

Data from the participants' CGM system (via Dexcom Clarity) and the Fishers Watch App for the periods between virtual visit 1- visit 2, visit 2-visit 3 and visit 3-visit 4 will be collected.

DURATION OF STUDY PARTICIPATION

* Duration of study participation for each patient - 12 months

PATIENT SAFETY SAFETY ENDPOINTS ASSESSED IN THIS STUDY

* Clinical safety * Adverse event collection

SAFETY INSTRUCTIONS

* Self-measured capillary blood glucose * Hypoglycaemia * Local tolerability * Allergic or allergic-like reaction

ADVERSE EVENT REPORTING Any adverse events will be reported to the Sponsor within 72 hours of becoming known to the research team. The MCA has agreed to inform the research team when made aware of any seafarers' adverse health events, including any injuries as a result of deranged glucose levels

ANNUAL SAFETY REPORTING and END of STUDY REPORTING

At the end of the year from the initiation date of the study, an annual report will be submitted to the University Ethics committee. At the end of the study, an end study report with all the data will also be submitted to both the Sponsor and the University Ethics Committee.

Participants will be withdrawn from the study by investigators if:

1. Participants experience an adverse reaction to the sensor (e.g. severe allergic reaction or intolerance) 2. The participant develops a medical condition either prior to entering or during the study, which may compromise their safety during free-living or seafaring activities and/or adversely and affect the outcome of the study. 3. The participant is consistently non-compliant.

Unless the participant specifically requests that their data is not used, all data prior to subject withdrawal will be used in analysis, however the deadline for withdrawal will be 7 days following completion of the study, as this is when statistical analysis will be completed.

Data analysis methods * Data collected from visit 1, visit 2, visit 3 and visit 4 and further data from the participants' logbooks will be transcribed by the PI responsible at the MCA site. * The CGMS/Flash data will be held on the readers and on the cloud, a copy of which will be sent to the PI and the investigators at the University of Surrey. * Data per participant will be coded and anonymized using SeaGM 001 to SeaGM 050. * Glucose variability on land before departure and during their time at sea * The variability in normal living and the time in and out of range will be calculated using the data from the CGM/Flash devices, collected by the PI. * The data from Fishers Watch web-app will be downloaded and saved by the PI and the investigators at the University of Surrey on the University computer as excel files for participants SeaGM 01 to SeaGM 50. * Questionnaire data will be analysed. * Simple statistical analysis will be performed using SPSS and Excel.

ANALYSIS POPULATIONS

• Efficacy populations - all patients who complete the 12 months study. There will be an interim analysis of the data at the 3, 6 and 12 months' time points.

• Glucose variability while working or on rest period at sea [Срок оценки: 12 months]
• Time in and out of range while seafaring (targets used as other clinical trials) [Срок оценки: 12 months]
• Feasibility and safety assessment of using CGM systems during seafaring activities [Срок оценки: 12 months]
• Questionnaire data an overview of participants' preferences [Срок оценки: 12 months]