Time in Range (TIR) has achieved global recognition as a key metric obtained from continuous glucose monitoring.1 Results from an independent global survey of more than 1,700 HCPs revealed that many agree that the metric is changing the diabetes management course, and is likely to become the standard of management in the future.2,3 TIR provides a more detailed picture of blood glucose that can enable precision in control that HbA1c cannot offer alone.1,4,5 To analyse and utilise TIR data it is necessary to interpret the ambulatory glucose profile (AGP) report, and the global HCP survey has highlighted that appropriate training and education would support the adoption of TIR in clinical practice.2
The compelling rationale for adopting Time in Range
The driving benefit of TIR is the extensive insight into glycaemic variability that it reveals, which is far beyond HbA1c.1,5 It is widely accepted that glycaemic variability (GV) provides a more meaningful measure of diabetes management and correlates with poor outcomes, yet despite its clinical significance there had previously been no consensus for the ideal means of characterising GV.6 TIR, along with the related metrics time below range (TBR) and time above range (TAR) offers a solution. It reveals the variability during each 24-hour period over a minimum of 14-days, to provide a personalised story about an individual’s glucose levels that reflects daily fluctuations.1
Time in Range (TIR) is a practical tool that can empower HCPs and people with diabetes with the knowledge and insights they need to make informed clinical and diabetes self management decisions.2,7 Findings from patient qualitative research indicate that information from TIR can improve motivation for self-management and positive lifestyle changes.7 And these benefits can result in notably improved disease control.1,8 Read this article to discover more about the value of Time in Range (TIR) as a diabetes tool.
In the large global HCP survey, participants agreed on the benefits of using Time in Range (TIR) to help manage diabetes, and the majority of HCPs identified saving time for themselves and their patients as one of the main benefits of TIR.2,3 The real-time actionable insights into glucose levels can improve the quality of patient care by informing better conversations and enabling individualised management.1,4,9
As a metric, Time in Range (TIR) has the potential for improving how diabetes is managed and supporting clinical care, once HCPs, patients and stakeholders become more familiar with its use, Continuous glucose monitoring is the crucial first step.10 The following downloadable guide suggests some conversation prompts for discussions with patients about starting to use a continual glucose monitor (CGM).
TIR embeds a new paradigm ‘CGM first’ and is supported by growing recommendation
CGM is now considered standard of care for people living with type 1 diabetes, and the current American Diabetes Association Standards now expand the cohort of patients suitable for CGM to include those with Type 2 diabetes receiving insulin treatment, as well as those with Type 1 diabetes.5 The expanded recommendations are due to growing evidence that CGM use can greatly enhance management for people with T2D patients receiving basal bolus or background and mealtime insulin.5
ADA Standards advise that CGM should be offered for management of type 1 diabetes and type 2 diabetes in adults and youths that receive insulin as multiple daily injections or infusion treatment, and to all those on basal insulin.5
Professor Christophe De Block and Associate Professor Julia Mader discuss the implications of guidelines for CGM and TIR use
A best practice approach outlined in the CGM ‘Playbook’ published by the Association of Diabetes Care and Education Specialists expands these selection criteria further, recommending that CGM should be considered for people with type 1 or type 2 diabetes and frequent hypoglycaemia or hypoglycaemia unawareness, or with high glycaemic variability, or not achieving glucose targets.11
The following downloadable resources outline the CGM references most useful in clinical practice. One lists the ten core CGM metrics internationally agreed to be most relevant for clinical management of diabetes, and the other is a decision tool to help identify patients most suitable for CGM:
Unlocking insights from the diabetes AGP report
The International Diabetes Center created software to generate the single, standardised ambulatory glucose profile (AGP) report in 2013, in order to make CGM data easy to use.12 It has since been updated with new versions which have been periodically released.12 The AGP report is intended for use both in the clinic and by patients in between visits. Modern CGM devices, as well as insulin pen and pump manufacturers, now offer the same version of the AGP within their reporting software.13
"The most important aspect is we train the HCPs into how to sufficiently use AGP data… they can analyse these data within ten minutes"
The AGP helps translate numerical CGM data into visual format for easy, quick interpretation. Research has shown that downloading data and creating the report could save 4-19 minutes per patient visit and permits more time for shared decision-making discussions.12 This article outlines the time-efficiency of AGP with Time in Range analysis.
It can help to take a systematic, structured approach to interpreting the AGP report.8 The report is intuitively divided into three sections and can be examined in a logical stepwise process, as illustrated in the following downloadable guide:
Clinical interpretation and use of TIR information
Percentage Time in Range (TIR) shown on the AGP can be visualised and interpreted as an absolute number of hours per day, for ease of understanding. TIR is influenced by all of the known factors that affect daily glucose levels including glucose excursions and mealtime peaks, carbohydrate content and glycaemic index of food; insulin doses and timings, especially around mealtimes, stress and anxiety, exercise and physical health.14 In conversation with patients, the potential reasons for time above or below range can be identified, such as forgetting an insulin injection, consuming too much or insufficient food, or the impact of exercise or alcohol. 14-17
All the established clinical behaviours for managing unwanted high or low glucose can be employed in shared decision-making about how best to improve Time in Range (TIR) and restrict time above and time below range.1,14 The defined percentage targets allow for the setting of Specific, Measurable, Achievable, Relevant, Time-bound (SMART) goals, which can be more accessible and achievable than targets set for improvements in HbA1c. TIR is rapidly responsive to changes in diet, lifestyle and medication.1,14
As a summary metric, Time in Range (TIR) needs to be used in conjunction with detailed information on glucose patterns for optimal use in clinical practice.14 These patterns are shown in the ambulatory glucose profiles in sections two and three of the AGP. They allow HCPs and people with diabetes to identify trends in daily glucose control which can be addressed if necessary, at appropriate times during the day or week, to stabilise glucose levels.14
Read this article for a practical overview of how to encourage patients to engage in behaviours that could increase their Time in Range (TIR). It contains some downloadable patient-friendly ‘Top Tips’ for sharing with your patients.
HQ22DI00277 June 2023