A new ‘best practice guide’ urges UK healthcare professionals to embrace the ‘time in range’ metric for patients with diabetes who use continuous glucose monitoring (CGM), particularly in light of the COVID-19 pandemic.
Time in range: a best practice guide for UK diabetes healthcare professionals in the context of the COVID-19 global pandemic, was published October 19 2020 in Diabetic Medicine by Dr Emma Wilmot of the diabetes department, Royal Derby Hospital, University Hospitals of Derby and Burton NHS Foundation Trust, Derby, and colleagues. The document is a publication of the Diabetes Technology Network (DTN) UK, part of the Association of British Clinical Diabetologists (ABCD).
In June 2019, an international consensus report established the ‘time in range’ concept – the proportion of time a person’s blood glucose falls within a prescribed range – as a clinical metric for patients with type 1 or type 2 diabetes who use either real-time CGM (rtCGM) or intermittently scanned CGM (isCGM), also called ‘flash glucose monitoring’. The latter, the Abbott FreeStyle Libre, is the one most commonly used in the UK, although the NHS in England has recently authorised the Dexcom G6 rtCGM for use during pregnancy.
The new guidance aims to clarify the intent and purpose of the international consensus recommendations and provide practical clinical and technical advice for use of time in range in UK diabetes care, particularly in the context of the COVID-19 pandemic, co-author Pratik Choudhary, professor of diabetes at the University of Leicester, told Medscape Medical News.
“Even though FreeStyle Libre has been widely rolled out and people are seeing the reports, we felt that a locally-published paper by local leaders of the DTN was needed to get people to start thinking about time in range. People are still fixated on haemoglobin A1c (HbA1c) and glucose of 5 [mmol/L],” Prof Choudhary said.
The paper reviews and provides rationale for the international guidelines, which recommend generally that more than 70% of glucose readings should fall within a blood glucose range of 3.9-10.0 mmol/L, with modifications for children, older adults, and pregnant women.
“It’s a huge mindset [change] from saying your target is 5 [mmol/l] to saying you’ve got a target range. It’s saying you’ve got an allowance of 30%, so if you screw up a little bit it’s not a disaster. It will balance out. That’s the narrative we want to put out there,” Prof Choudhary explained.
A UK-based audit on the use of FreeStyle Libre conducted by ABCD showed significant improvements in HbA1c, reduced hospital admissions, and lower levels of diabetes-related distress in patients with type 1 diabetes. Updated data from that study were published in the September 2020 issue of Diabetes Care.
The new document emphasises that time in range is meant as an adjunct to HbA1c rather than a surrogate, and discusses the correlations between the two values and their respective association with diabetes-related outcomes. However, because the COVID-19 pandemic has reduced the capacity for in-person visits including blood tests,