UK Diabetes Clinicians Urged to Embrace 'Time in Range' 

Miriam E. Tucker 

November 02, 2020

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). 

Real-time CGM

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.

International Guidelines

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.

Remote Monitoring

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, earlier this year ABCD advised that remote consultations using digital technology be utilised as much as possible during the pandemic.

Such remote data monitoring is possible via apps (LibreView for FreeStyle Libre, Clarity for Dexcom). In addition to reporting percentages of time in range and time above or below range, both systems also provide an estimated HbA1c or 'glucose management indicator', which roughly approximates HbA1c values based on the continuous readings.

"In the COVID era, blood glucose control is one of the only modifiable risk factors [for COVID-19 severity]. The LibreView supports remote monitoring. Without that, we wouldn’t have been able to support people during the pandemic," Prof Choudhary said, noting that he currently has about 1300 patients with type 1 diabetes using FreeStyle Libre and hasn’t seen any patients face-to-face since March.

The DTN’s education web page currently has videos on use of both rtCGM and isCGM, with more due to be posted in the coming months. The same videos are designed to educate both patients and clinicians, Prof Choudhary said. "It’s important for doctors and patients to be speaking the same language. Otherwise, consultations are ineffective…Time in range is the new language."   

Prof Choudhary has received personal fees from Abbott Diabetes Care, Dexcom, Medtronic, Insulet, Roche, Novo Nordisk, Lilly, Sanofi and Novartis.

Published October 19, 2020 in Diabetic Medicine


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.