Endocrine Abstracts (2016) 45 OC7.4 | DOI: 10.1530/endoabs.45.OC7.4

Accuracy and patient experience of the novel flash glucose monitoring system in children and young people with type 1 diabetes mellitus

Lucy Turner, Hussain Alsaffar, Anna Simmons, Anna Bradley, Kathryn Millar, Noala Bradshaw, Emma O’Sullivan, Keith Thornborough, Jonathan Mimnagh, Sue Kerr, Fulya Mehta, Princy Paul, Atrayee Ghatak & Senthil Senniappan

Alder Hey Children’s Hospital, Liverpool, UK.

Background: FreeStyle Libre flash glucose monitoring system (FSL) has recently gained popularity as it can potentially reduce the number of finger prick capillary blood glucose tests (CBG). Initial short-term studies in adults have demonstrated accuracy although there is no paediatric data available to date. We aimed to assess the accuracy of FSL in children and young people and evaluated the user experience in routine clinical practice.

Methods: About 310 datasets of corresponding CBG and FSL readings were available from 8 T1DM patients (8–18 years) who were enrolled in two-week trial of FSL. A detailed questionnaire was completed at the end of the trial period.

Results: The mean (+SD) variation of the FSL readings compared to CBG was 0.92 mmol/l (+1.18)]. The overall mean absolute relative difference (MARD) was 10.9% and 12% of the episodes had a discrepancy of >2 mmol/l. The mean number of swipes per day was 10 and FSL revealed an average of 8% time spent in the hypoglycaemic range. The mean (+SD) variation during hypoglycaemia (<4 mmol/l) was 0.42 mmol/l (+0.32)]. About 88% of values were within the reference standard (±0.83 mmol/l) at glucose concentrations less than 5.6 mmol/l. The sensor lasted for an average duration of 7 days. All patients rated convenience and ease of use as high (4–5 out of 5) on a self-measured scale with 75% reporting an improved quality of life with FSL. A substantial percentage of young people found FSL to be more “socially acceptable” than finger prick testing.

Conclusions: We report the first paediatric data on patient experience and accuracy of FSL in routine clinical practice. FSL provides more data on glucose levels/trends and patients find the system convenient for routine use. Although the overall accuracy is reasonable, some extreme variations are noted. Only around half of the patients stated that they would rely on FSL for dose calculations/hypoglycaemia management. The limited longevity of the sensor in routine clinical practice has potential cost implications. Further long term studies of a larger sample size are required to understand the accuracy, long term efficacy and safety of FSL in children and young people.