Skip to content

Flash-glucose Monitoring in Sub-optimally Controlled Type 1 Diabetes (FLASH-UK)

An Open-label, Multi-centre, Randomised, Parallel Design Study to Assess the Efficacy of Flash Glucose Monitoring in Adults With Sub-optimally Controlled Type 1 Diabetes.

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03815006
Acronym
FLASH-UK
Enrollment
156
Registered
2019-01-24
Start date
2020-01-09
Completion date
2021-10-10
Last updated
2023-10-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Diabetes Mellitus, Type 1

Brief summary

FreeStyle Libre (FSL2) is a novel glucose monitoring device (Flash glucose monitoring) in the form of a disc worn on the arm for 14 days, and a hand-held reader which is designed to largely replace the recommended 4-10 painful finger-stick blood glucose tests required each day for the self-management of type 1 diabetes. The purpose of this study is to determine whether flash glucose monitoring with FSL2 device will improve HbA1c over 24 weeks compared to self-monitoring of blood glucose in adults and adolescents (16 or older) with sub-optimally controlled (HbA1c 7.5% to 11%) type 1 diabetes. This is an open-label, multi-centre, randomised, parallel design study, involving a 2-week run-in period, followed by a 24-week study period during which participants will use either FSL2 or continue usual finger-stick glucose monitoring in random order. A total of up to 156 randomised participants from up to 180 recruited aged 16 years and older with T1D on insulin pump therapy or multiple daily injection therapy were recruited through diabetes clinics in participating centres. Participants will receive appropriate training to maximise the benefits of FSL2 and finger-stick glucose levels in self-management. The primary outcome is the difference in HbA1c between the two groups at 24 weeks. Secondary outcomes are time spent with glucose levels above and below target, as recorded by FSL2, and other flash glucose-based metrics. Impact on quality of life, diabetes distress, mood, needle burden, disordered eating and treatment satisfaction will also be undertaken. Relative cost-effectiveness of FSL2 device compared with self-monitoring will also be assessed from a UK NHS perspective.

Detailed description

Study Design: An open-label, multi-centre, randomised, parallel study, in adults and adolescents (16 years and older) with type 1 diabetes and sub-optimal glycaemic control (HbA1c 7.5% to 11%), either on insulin pump treatment or multiple daily injections, contrasting flash glucose monitoring using FreeStyle Libre 2 device with traditional finger-stick glucose monitoring for 24 weeks. Expecting approximately 15% to 20% dropout rate recruitment will aim for 180 participants aiming for 156 randomised and 128 completed participants. Participant Recruitment: This is a UK multi-centre and recruitment will take place at the following centres: 1. Diabetes Centres within Manchester University Foundation Trust 2. Royal Derby Hospital, Derby 3. Queen Elizabeth Hospital, Birmingham 4. Addenbrookes Hospital, Cambridge 5. Norfolk and Norwich University Hospital, Norwich 6. Queen Alexandra Hospital, Portsmouth 7. Ipswich Hospital 8. The Adam Practice, Dorset Each centre will aim to recruit between 25 to 30 participants. Additional diabetes centres surrounding above hospitals may act as participant identification centres. Potential participants will be identified by their treating clinicians and invited to contact the research team. They will be sent the study information leaflets and an invitation by post or in-person to join the study by the research team at least one day before the recruitment visit. The study may also be advertised via social media. After recruitment, consent, subjects will be randomised for 24-weeks home use of flash-glucose monitoring or 24-weeks use finger-stick glucose monitoring. Study Visits: The study includes up to 7 visits for participants completing the study. Maximum time in study is 30 weeks. Each study visit can be scheduled with +/- 2 weeks of the planned visit date. Visit 1: Recruitment Visit and Screening Assessment Once the participants have agreed to participate in the study, they will be invited for the recruitment visit, and given a participant ID, when the following activities will be performed by the research team: * written informed consent/assent * checking inclusion and exclusion criteria * medical and diabetes history including the presence of diabetes complications and hypoglycaemia burden * ethnicity, body weight and height measurement; calculation of BMI * record of current insulin therapy * urine or blood pregnancy test (females of child-bearing potential) * record of occupation and educational attainment * any history of disordered eating or needle phobia * previous participation in structured education, the status of carb counting, use of bolus calculator Screening Blood Sampling Blood samples will be taken to measure HbA1c (measured at the local laboratory if not done within the last two weeks). Renal and Thyroid function will also be evaluated (if not done in last one year). Less than 15 ml of whole blood will be taken from each participant. Questionnaires at screening Evaluation of participants' responses in terms of quality of life, diabetes distress, needle burden, disordered eating, depression and diabetes treatment satisfaction using 1. EQ-5DL-5L questionnaire 2. Type 1 Diabetes Distress Scale (DDS), 3. Diabetes fear of injecting and self-testing (D-FISQ) questionnaire, 4. Diabetes Eating Problem Survey (DEPS-R), 5. Diabetes Treatment Satisfaction Questionnaire (DTSQ), 6. Patient Health Questionnaire (PHQ-9) and 7. The Glucose Monitoring Satisfaction Survey (GMSS). 8. Hypoglycaemia burden will be assessed using Clarke questionnaire and Gold score. Visit 2: Insertion of the blinded glucose monitoring device Purpose of visit 2 is to insert a blinded glucose monitor (FreeStyle Libre Pro device). The participant will be provided with instructions about using this device for the next two weeks. Visit two may be combined with visit 1. Visit 3: Adherence assessment, randomisation and the start of study treatment During Visit 3, participant's adherence/tolerance of using the flash-CGM over preceding 14 days will be assessed. To proceed with the study participant should have worn the blinded glucose monitoring device for at least ten days' during the last 14 days of the run-in period. If the participant fails to demonstrate adherence or develops any significant allergy or intolerance to the glucose sensor, the study will be terminated, and the participant will be removed from the study. Participant randomisation for the treatment intervention will take place during visit 3. Initiation of study treatment The participant will arrive at the clinical facility or clinic at the agreed time. Body weight measurement will be made. Participants will be provided with necessary training on the use of study devices according to randomisation. Training session Participants randomised to flash-glucose monitoring arm will receive education and training about insertion and initiation of the sensor as well as how to use flash-glucose monitoring data for treatment optimisation. They will be encouraged to download data at home to identify pattern recognition. This session will be conducted by a professional diabetes educator or a member of the study team. Education will be tailored to meet the needs of the individual. Participants randomised to conventional finger-stick glucose monitoring arm will be encouraged to use finger-stick glucose levels to optimise treatment and will receive education about insulin dose adjustments using finger-stick glucose levels. The study will try to mimic real-life conditions by continuing participants pre-study diabetes treatment unchanged and finger-stick glucose testing frequency as determined by the participant as required. Participants in both arms will also receive training on sick day rules and dealing with hypo and hyperglycaemia. Participants will be provided with a paper diary to collect information about insulin doses and carbohydrate intake in the last three days of each study month. Visit 4: (+4 weeks since randomisation): Review data and treatment optimisation Purpose of this visit is to review data from Flash-glucose monitoring and finger-stick glucose monitoring to further optimise treatment. Study devices will be downloaded. Information about insulin doses and any adverse events will be collected. Visit 5: (+12 weeks since randomisation): Review data and treatment optimisation Purpose of this visit is to review data from Flash-glucose monitoring and finger-stick glucose monitoring to further optimise treatment. Study devices will be downloaded. Information about insulin doses, participant diaries and any adverse events will be collected. A blood sample will be collected for HbA1c. Visit 6: (+22 weeks since randomisation): Finger-stick glucose monitoring arm only Participants randomised to finger-stick glucose monitoring arm will have an extra visit ten weeks after visit 5 to insert a blinded glucose sensor for data capture. Visit 7: (+24 weeks since randomisation): End of randomised study treatment The participant will be invited to attend the research centre approximately 12 weeks after Visit 5. This would be the end of 24 weeks randomised study period. All study devices will be downloaded. Insulin usage data will be recorded and diaries collected. The participant will have a blood test for the HbA1c. Body weight measurement will be made. The participant will be asked to complete the same questionnaires completed at Visit 1. In addition, participants in the FSL2 arm will be asked to complete a additional questionnaire exploring expectations and experience of using FSL2 during the study. A subset of participants (n=40 aiming for 25 completed questionnaires) in the FSL2 arm and subset of researchers (n=10) will also be asked to complete additional questionnaires to help with the process evaluation.

Interventions

DEVICEFree Style Libre 2

FreeStyle Libre 2 (FSL2) is a novel glucose monitoring device (Flash glucose monitoring) in the form of a disc worn on the arm for 14 days and a hand-held reader which is designed to largely replace the recommended 4-10 painful finger-stick blood glucose tests required each day for the self-management of type 1 diabetes (T1D).

Sponsors

University Hospitals of Derby and Burton NHS Foundation Trust
CollaboratorOTHER
Cambridge University Hospitals NHS Foundation Trust
CollaboratorOTHER
Portsmouth Hospitals NHS Trust
CollaboratorOTHER_GOV
University Hospital Birmingham NHS Foundation Trust
CollaboratorOTHER
Norfolk and Norwich University Hospitals NHS Foundation Trust
CollaboratorOTHER
University of Manchester
CollaboratorOTHER
Diabetes UK
CollaboratorOTHER
Clinical Trials Unit, Manchester
CollaboratorOTHER
BHR Limited
CollaboratorINDUSTRY
East Suffolk and North Essex NHS Foundation Trust
CollaboratorOTHER
The Adam Practice
CollaboratorOTHER
Manchester University NHS Foundation Trust
Lead SponsorOTHER_GOV

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
16 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* The participant is ≥16 years old * The participant has type 1 diabetes, as defined by WHO for at least 1 year or is confirmed C-peptide negative if duration of diabetes is \< 1 years * Participant is treated with insulin pump or multiple daily injection for at least 12 weeks and no plans to change treatment modality during next 28 weeks * The participant is literate in English for safe study conduct * Screening HbA1c ≥ 7.5% (58.5mmol/mol) and ≤ 11% (97 mmol/mol) based on analysis from local laboratory * The participant is willing to wear study glucose sensor and scan for glucose levels at regular intervals * The participant is willing to follow study specific instructions and improve glucose control * Female participants of child bearing age should be on effective contraception and must have a negative blood or urine pregnancy test at screening. * The participant adopting a virtual pathway through the trial is able and willing to post study devices, questionnaires and blood collection kits back to the research team or to the laboratory using pre-paid postal services. * The participant adopting a virtual pathway through the trial has internet connection, appropriate videoconferencing software and supporting devices to undertake video consultations where necessary.

Exclusion criteria

Key

Design outcomes

Primary

MeasureTime frameDescription
HbA1c Level at 24 Weeks24 weeksThe primary outcome is difference in HbA1c between the two groups at 24 weeks.

Secondary

MeasureTime frameDescription
Percentage With HbA1c ≤ 53 mmol/Mol (7.0%) at 12 Weeks12 weeksThis is the comparison between arms of percentage with HbA1c ≤ 53 mmol/mol (7.0%) at 12 weeks
Percentage With HbA1c ≤ 53 mmol/Mol (7.0%) at 24 Weeks24 weeksThis is the comparison between arms of percentage with HbA1c ≤ 53 mmol/mol (7.0%) at 24 weeks
Sensor Based - Time Spent in the Target Glucose Range Between 3.9 to 10.0 mmol/l24 weeksTime spent in the target glucose range between 3.9 to 10.0 mmol/l (70 to 180mg/dl).
Sensor Based - Time Spent Below Target Glucose (<3.9mmol/l)24 weeksTime spent below target glucose (\<3.9mmol/l) (\<70mg/dl)
Sensor Based - Time Spent Above Target Glucose (10.0 mmol/l)24 weeksTime spent above target glucose (10.0 mmol/l) (180 mg/dl)
Sensor Based - Average Glucose Levels24 weeksAverage glucose levels
Sensor Based - Standard Deviation Glucose Levels24 weeksStandard deviation glucose levels
Sensor Based - Coefficient of Variation Glucose Levels24 weeksCoefficient of variation glucose levels
Sensor Based - Time With Sensor Glucose Levels < 3.5 mmol/l24 weeksThe time with sensor glucose levels \< 3.5 mmol/l (63 mg/dl)
Sensor Based - Time With Sensor Glucose Levels < 2.8 mmol/l24 weeksThe time with sensor glucose levels \< 2.8 mmol/l (50 mg/dl)
Sensor Based - Time With Sensor Glucose Levels in the Significant Hyperglycaemia24 weeksThe time with sensor glucose levels in the significant hyperglycaemia (glucose levels \> 16.7 mmol/l) (300mg/dl)
Sensor Based - AUC of Glucose Below 3.0mmol/l24 weeksAUC of glucose below 3.0mmol/l (54mg/dl)
Total Daily Average Insulin Dose24 weeksComparison between arms of Total daily average insulin dose
Daily Average Basal Insulin Dose24 weeksComparison between arms of Daily average basal insulin dose
HbA1c Level at 12 Weeks12 weeksThis is the difference in HbA1c between the two groups at 12 weeks
Average Number of Boluses of Rapid Acting Insulin24 weeksAverage number of boluses of rapid acting insulin per day
Number of Freestyle Libre Scans Per Day24 weeksNumber of Freestyle Libre scans per day in the intervention arm only
Frequency of Severe Hypoglycaemic Episodes24 weeksFrequency of severe hypoglycaemic episodes as defined by American Diabetes Association
Frequency of Significant Ketosis Events24 weeksFrequency of significant ketosis events (plasma ketones \>3mmol/l)
Nature and Severity of Other Adverse Events24 weeksNature and severity of other adverse events.
Type 1 Diabetes Distress Scale Score24 weeksType 1 Diabetes Distress Scale score compared between arms
EQ-5D-5L Quality of Life Questionnaire Score24 weeksEQ-5D-5L Quality of Life questionnaire
Patient Health Questionnaire Score24 weeksPatient Health Questionnaire: score of 5-9 would be minimal symptoms. any score large than 20 would be categorised as severe major depression
Diabetes Fear of Injecting and Self-Testing Questionnaire Score24 weeksDiabetes fear of injecting and self-testing questionnaire: 15 questions, 6 for Fear of Self injecting, 9 for fear of self testing.
The Revised Diabetes Eating Problem Survey Score24 weeksThe revised Diabetes Eating Problem Survey
Average Number of Days of Libre Usage Per Week24 weeksAverage number of days of usage per week
Diabetes Treatment Satisfaction Questionnaire Score24 weeksDiabetes Treatment Satisfaction Questionnaire
Glucose Monitoring Satisfaction Survey Score24 weeksGlucose Monitoring Satisfaction Survey: 15 questions ranging from 1-5.
Daily Average Bolus Dose24 weeksComparison between arms of Daily average bolus dose

Countries

United Kingdom

Participant flow

Participants by arm

ArmCount
Free Style Libre 2 Device
At the start, a blood sample will be taken for the measurement of HbA1c. Training and education on the use of FSL2 will be provided by the research team. Participants will be advised to use flash glucose monitoring continuously for the next 24 weeks. Free Style Libre 2: FreeStyle Libre 2 (FSL2) is a novel glucose monitoring device (Flash glucose monitoring) in the form of a disc worn on the arm for 14 days and a hand-held reader which is designed to largely replace the recommended 4-10 painful finger-stick blood glucose tests required each day for the self-management of type 1 diabetes (T1D).
78
Self-monitoring of Blood Glucose
At the start, a blood sample will be taken for the measurement of HbA1c. Masked FSL will be applied for two weeks, during the last two weeks of control period. Education will focus on using fingerstick measurement for treatment optimisation.
78
Total156

Baseline characteristics

CharacteristicFree Style Libre 2 DeviceSelf-monitoring of Blood GlucoseTotal
Age, Continuous44 years
STANDARD_DEVIATION 14
44 years
STANDARD_DEVIATION 15
44 years
STANDARD_DEVIATION 15
Glycated Haemoglobin levels71.6 mmol/mol
STANDARD_DEVIATION 9.5
69.9 mmol/mol
STANDARD_DEVIATION 8.5
70.8 mmol/mol
STANDARD_DEVIATION 9
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants3 Participants3 Participants
Race (NIH/OMB)
Black or African American
0 Participants0 Participants0 Participants
Race (NIH/OMB)
More than one race
1 Participants0 Participants1 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
77 Participants75 Participants152 Participants
Region of Enrollment
United Kingdom
78 participants78 participants156 participants
Sex: Female, Male
Female
33 Participants36 Participants69 Participants
Sex: Female, Male
Male
45 Participants42 Participants87 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 780 / 78
other
Total, other adverse events
1 / 780 / 78
serious
Total, serious adverse events
2 / 782 / 78

Outcome results

Primary

HbA1c Level at 24 Weeks

The primary outcome is difference in HbA1c between the two groups at 24 weeks.

Time frame: 24 weeks

ArmMeasureValue (MEAN)Dispersion
Free Style Libre 2 DeviceHbA1c Level at 24 Weeks62.8 mmol/molStandard Deviation 8.5
Self-monitoring of Blood GlucoseHbA1c Level at 24 Weeks67.7 mmol/molStandard Deviation 9.8
Secondary

Average Number of Boluses of Rapid Acting Insulin

Average number of boluses of rapid acting insulin per day

Time frame: 24 weeks

Secondary

Average Number of Days of Libre Usage Per Week

Average number of days of usage per week

Time frame: 24 weeks

Secondary

Daily Average Basal Insulin Dose

Comparison between arms of Daily average basal insulin dose

Time frame: 24 weeks

Secondary

Daily Average Bolus Dose

Comparison between arms of Daily average bolus dose

Time frame: 24 weeks

Secondary

Diabetes Fear of Injecting and Self-Testing Questionnaire Score

Diabetes fear of injecting and self-testing questionnaire: 15 questions, 6 for Fear of Self injecting, 9 for fear of self testing.

Time frame: 24 weeks

Secondary

Diabetes Treatment Satisfaction Questionnaire Score

Diabetes Treatment Satisfaction Questionnaire

Time frame: 24 weeks

Secondary

EQ-5D-5L Quality of Life Questionnaire Score

EQ-5D-5L Quality of Life questionnaire

Time frame: 24 weeks

Secondary

Frequency of Severe Hypoglycaemic Episodes

Frequency of severe hypoglycaemic episodes as defined by American Diabetes Association

Time frame: 24 weeks

Secondary

Frequency of Significant Ketosis Events

Frequency of significant ketosis events (plasma ketones \>3mmol/l)

Time frame: 24 weeks

Secondary

Glucose Monitoring Satisfaction Survey Score

Glucose Monitoring Satisfaction Survey: 15 questions ranging from 1-5.

Time frame: 24 weeks

Secondary

HbA1c Level at 12 Weeks

This is the difference in HbA1c between the two groups at 12 weeks

Time frame: 12 weeks

Secondary

Nature and Severity of Other Adverse Events

Nature and severity of other adverse events.

Time frame: 24 weeks

Secondary

Number of Freestyle Libre Scans Per Day

Number of Freestyle Libre scans per day in the intervention arm only

Time frame: 24 weeks

Secondary

Patient Health Questionnaire Score

Patient Health Questionnaire: score of 5-9 would be minimal symptoms. any score large than 20 would be categorised as severe major depression

Time frame: 24 weeks

Secondary

Percentage With HbA1c ≤ 53 mmol/Mol (7.0%) at 12 Weeks

This is the comparison between arms of percentage with HbA1c ≤ 53 mmol/mol (7.0%) at 12 weeks

Time frame: 12 weeks

Secondary

Percentage With HbA1c ≤ 53 mmol/Mol (7.0%) at 24 Weeks

This is the comparison between arms of percentage with HbA1c ≤ 53 mmol/mol (7.0%) at 24 weeks

Time frame: 24 weeks

Secondary

Sensor Based - AUC of Glucose Below 3.0mmol/l

AUC of glucose below 3.0mmol/l (54mg/dl)

Time frame: 24 weeks

Secondary

Sensor Based - Average Glucose Levels

Average glucose levels

Time frame: 24 weeks

Secondary

Sensor Based - Coefficient of Variation Glucose Levels

Coefficient of variation glucose levels

Time frame: 24 weeks

Secondary

Sensor Based - Standard Deviation Glucose Levels

Standard deviation glucose levels

Time frame: 24 weeks

Secondary

Sensor Based - Time Spent Above Target Glucose (10.0 mmol/l)

Time spent above target glucose (10.0 mmol/l) (180 mg/dl)

Time frame: 24 weeks

Secondary

Sensor Based - Time Spent Below Target Glucose (<3.9mmol/l)

Time spent below target glucose (\<3.9mmol/l) (\<70mg/dl)

Time frame: 24 weeks

Secondary

Sensor Based - Time Spent in the Target Glucose Range Between 3.9 to 10.0 mmol/l

Time spent in the target glucose range between 3.9 to 10.0 mmol/l (70 to 180mg/dl).

Time frame: 24 weeks

Secondary

Sensor Based - Time With Sensor Glucose Levels < 2.8 mmol/l

The time with sensor glucose levels \< 2.8 mmol/l (50 mg/dl)

Time frame: 24 weeks

Secondary

Sensor Based - Time With Sensor Glucose Levels < 3.5 mmol/l

The time with sensor glucose levels \< 3.5 mmol/l (63 mg/dl)

Time frame: 24 weeks

Secondary

Sensor Based - Time With Sensor Glucose Levels < 3.5 mmol/l

The time with sensor glucose levels \< 3.0 (54mg/dl)

Time frame: 24 weeks

Secondary

Sensor Based - Time With Sensor Glucose Levels in the Significant Hyperglycaemia

The time with sensor glucose levels in the significant hyperglycaemia (glucose levels \> 16.7 mmol/l) (300mg/dl)

Time frame: 24 weeks

Secondary

The Revised Diabetes Eating Problem Survey Score

The revised Diabetes Eating Problem Survey

Time frame: 24 weeks

Secondary

Total Daily Average Insulin Dose

Comparison between arms of Total daily average insulin dose

Time frame: 24 weeks

Secondary

Type 1 Diabetes Distress Scale Score

Type 1 Diabetes Distress Scale score compared between arms

Time frame: 24 weeks

Source: ClinicalTrials.gov · Data processed: Feb 15, 2026