Retrospective chart review of FreeStyle Libre in adults with type 2 diabetes using pre-mixed insulin

ISRCTN	ISRCTN12492837
DOI	https://doi.org/10.1186/ISRCTN12492837
IRAS number	350006
Secondary identifying numbers	ADC-UK-PMS-24060, CPMS 65134

Submission date: 13/01/2025
Registration date: 27/01/2025
Last edited: 12/02/2025

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Nutritional, Metabolic, Endocrine

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Diabetes is a lifelong condition where the amount of sugar in the blood is too high. The aim of this study is to review the effectiveness of the FreeStyle Libre Glucose Monitoring System in adults with Type 2 diabetes using pre-mix insulin.

Who can participate?
Patients aged 18 years or older, with type 2 diabetes

What does the study involve?
For each medical record, HbA1c (a measure of average blood glucose) will be collected after 3 to 6 months of use of the FreeStyle Libre and compared with HbA1c from before starting FreeStyle Libre.

What are the possible benefits and risks of participating?
There are no risks or direct benefits to patients whose medical records are included.

When is the study starting and how long is it expected to run for?
June 2024 to June 2025

Who is funding the study?
Abbott Diabetes Care Ltd

Who is the main contact?
Dr Pamela Reid, pamela.reid@abbott.com

Contact information

Dr Pamela Reid
Public, Scientific

Range Road
Witney
OX290YL
United Kingdom

Phone	+44 (0)1993 863024
Email	pamela.reid@abbott.com

Dr Thinzar Min
Principal Investigator

Room 111, Diabetes Research Unit
Swansea University Medical School
Port Talbot
SA2 8QA
United Kingdom

Phone	+44 (0)1639 862596
Email	Thinzar.min@wales.nhs.uk

Study information

Study design	Retrospective non-interventional chart review study
Primary study design	Observational
Secondary study design	Retrospective chart review study
Study setting(s)	Medical and other records
Study type	Other
Participant information sheet	Not applicable (retrospective study)
Scientific title	A retrospective, non-interventional, chart review study of the effectiveness of FreeStyle Libre in adults with type 2 diabetes using pre-mixed insulin
Study acronym	REFER-PREMIX
Study objectives	Effectiveness of FreeStyle Libre Glucose Monitoring Systems on glycaemic control versus standard of care measured by HbA1c, using patient records
Ethics approval(s)	Ethics approval not required
Ethics approval additional information	This is a retrospective observational study reviewing medical charts, which does not require ethics approval. The NHS HRA and UKRI Medical Research Council NHS REC checklist demonstrated that REC review is not required for England and Wales for this study, although the study was submitted and granted HRA and Health and Care Research Wales (HCRW) Approval.
Health condition(s) or problem(s) studied	Type 2 diabetes mellitus (diabetes)
Intervention	For each medical record, HbA1c (a measure of average blood glucose) will be collected after 3 to 6 months of use of the FreeStyle Libre and compared with HbA1c from before starting FreeStyle Libre.
Intervention type	Other
Primary outcome measure	Change in HbA1c from baseline to 3 to 6 months after initiation of FreeStyle Libre measured using patient records
Secondary outcome measures	There are no secondary outcome measures
Overall study start date	01/06/2024
Completion date	30/06/2025

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	Both
Target number of participants	At least 78 medical records that satisfy the inclusion/exclusion criteria
Key inclusion criteria	1. Age 18 years or over at the time of starting a FreeStyle Libre system 2. Has type 2 diabetes using pre-mixed insulin only or pre-mixed insulin in combination with oral and/or injectable (non-insulin) medications for at least 1 year prior to starting a FreeStyle Libre system 3. Has used a FreeStyle Libre system regularly for at least 3 months 4. HbA1c recorded in medical notes between 8.0% and 12.0% (64 to 108 mmol/mol) in the 3 months prior to starting a FreeStyle Libre system 5. HbA1c recorded in medical notes 3 to 6 months after starting a FreeStyle Libre system
Key exclusion criteria	1. Has used bolus or basal insulin during the data collection period 2. Female participant who was pregnant during the data collection period 3. Received dialysis treatment during the data collection period 4. Participated in another medical device or drug study that, in the Investigator’s opinion, could have affected glucose measurements or management during the data collection period
Date of first enrolment	15/01/2025
Date of final enrolment	30/06/2025

Locations

Countries of recruitment

England
United Kingdom
Wales

Study participating centres

Swansea Bay University LHB

Port Talbot
SA12 7BR
United Kingdom

Cardiff & Vale University LHB

Cardiff
CF14 4HH
United Kingdom

County Durham and Darlington FT

Darlington
DL3 6HX
United Kingdom

Hywel Dda University LHB

St Davids Park
Carmarthen
SA31 3BB
United Kingdom

Aneurin Bevan University LHB

Newport
NP18 3XQ
United Kingdom

Middleton and Dinsdale Medical Practice

Darlington
DL2 1BY
United Kingdom

Royal Glamorgan Hospital (CWM TAF MORG UNI LHB)

Llantrisant
CF72 8TA
United Kingdom

Sponsor information

Abbott Diabetes Care
Industry

Range Road
Witney
OX29 0YL
England
United Kingdom

Phone	+44 (0)1993 863024
Email	pamela.reid@abbott.com

Funders

Funder type

Industry

Abbott Diabetes Care
Private sector organisation / For-profit companies (industry)

Location: United States of America

Results and Publications

Intention to publish date	30/06/2026
Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Available on request
Publication and dissemination plan	Possible presentation at a diabetes conference, and/or publication in a peer-reviewed journal. The estimated timeline is 1 year from the trial end date.
IPD sharing plan	The datasets generated during and/or analysed during the current study are/will be available upon request from Pamela Reid (pamela.reid@abbott.com). All study data sourced for this study comes directly from data recorded in medical charts, so can be obtained from the original source via appropriate approval, rather than from the sponsor.

Editorial Notes

12/02/2025: Internal review.
31/01/2025: Internal review.
13/01/2025: Study's existence confirmed by the HRA.