CGM Intervention in Teens and Young Adults With Type 1 Diabetes (T1D)

Inclusion criteria

• Clinical diagnosis of T1D, with either age of T1D diagnosis < 10 years of age OR a history of positive T1D related antibodies in the medical record
• Age 14-<25 years
• Diabetes duration ≥ 1 year
• Total daily insulin requirement ≥ 0.4 units/kg/day
• HbA1c 7.5% to <11.0% (Point of care device or local lab measured as part of study at screening visit)
• Insulin regimen involves a consistent modality of insulin administration with either use of an insulin pump or at least 3 multiple daily injections of basal and bolus (meal time) analogue insulin. Insulin pump must not have been started within 3 months of consent with no plans to change regimens in the next 6 months
• Perform at least 2 blood glucose meter checks per day from self-report at screening and an average of at least 2 checks per day from meter download during blinded CGM run in
• Blinded CGM must be used a minimum of 200 hours (equivalent to 8.3 days) with an average of 1.8 calibrations per day during the blinded CGM screening period.
• Participant comprehends written and spoken English
• Participant understands the study protocol and agrees to it (if applicable)

Exclusion criteria

• Use of unblinded personal CGM and/or flash CGM, outside of a research study, as part of real-time diabetes management in the last 3 months
• Unable to use CGM device for minimum number of hours during blinded pre-randomization period or skin reaction from adhesive that would preclude participation in the randomized trial
• Started on non-insulin medication for blood glucose control within the past 3 months or plans to begin within the next 6 months
• The presence of a significant medical disorder that in the judgment of the investigator will affect the wearing of the sensors (such as a skin condition), or the completion of any aspect of the protocol.
• More than 1 episode of DKA in the past 6 months as defined in the adverse events chapter.
• The presence of any of the following diseases:

• Asthma or any condition present in the last 6 months where treatment is a systemic or daily inhaled corticosteroid (Intermittent treatment with inhaled corticosteroids does not exclude subjects from enrollment)
• Cystic fibrosis
• Addison's disease (Adequately treated thyroid disease and celiac disease do not exclude subjects from enrollment)
• Inpatient psychiatric treatment in the past 6 months or daily intensive outpatient psychiatric day treatment in the past 3 months.
• Pregnant (positive test confirmed at screening) or planning to become pregnant in the next 12 months.
• Need for use of acetaminophen or acetaminophen-containing products on a regular basis during the 6 months of the trial
• Participation in a diabetes related intervention study in the past 6 weeks.
• Any medical, psychological or social situation where per investigator discretion it may be difficult for participant to participate fully in the intervention
• Any condition, per investigator assessment, that could impact reliability of the A1C measurement, such as (but not limited to) hemoglobinopathy, hemolytic anemia, chronic liver disease; chronic GI blood loss, red blood cell transfusion or erythropoietin administration within 3 months prior to screening