2019: A Year of Time in Range
By Emily Fitts
Major milestones in 2019 brought time in range to the forefront of diabetes care
As the American Diabetes Association’s (ADA) 80th Scientific Sessions approach, we are reflecting on one of the most significant advancements in diabetes care in the past year – defining time in range targets and incorporating time in range into clinical practice standards. These developments build on many years of advocating for metrics that go Beyond A1C, such as time in range, to better capture the daily variations – the highs, low, and in range values – that characterize life with diabetes. Time in range is a powerful tool for people with diabetes to assess patterns in blood glucose levels throughout the day, which helps inform daily treatment decisions in a way that A1C cannot.
Achieving Consensus on Time in Range:
A landmark meeting at the 2019 Advanced Technologies & Treatments for Diabetes (ATTD) conference brought together a group of diabetes clinicians, researchers, and patient advocates to develop time in range targets using continuous glucose monitor (CGM) metrics. The outcome was a consensus on the goals for time in range, time above range, and time below range for various groups of people with diabetes, which were then published in Diabetes Care and presented at ADA 2019.
Establishing Time in Range Targets:
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For a person with type 1 or type 2 diabetes, the goal is to be in the target range (70-180 mg/dl) more than 70% of the time, with less than 4% spent in hypoglycemia (under 70 mg/dl).
For older or high-risk people with diabetes (sometimes referred to as “medically frail” diabetes), the goal is greater than 50% time in range, with less than 1% in hypoglycemia.
*According to the authors, “medically frail” diabetes occurs in someone who “can’t carry out the abilities of daily living without risk,” or who is terminally ill.
For pregnant women with type 1, the goal is over 70% in the tighter range of 63-140 mg/dl (linked to lower risk of newborn complications).
For pregnant women with gestational and type 2 diabetes, the goal is to spend the vast majority of the day in the tighter range of 63-140 mg/dl.
The target of greater than 70% time in range for a person with type 1 or type 2 diabetes was selected because it approximates an A1C of less than 7%, which has been shown to greatly reduce the risk of diabetes complications. Similar to A1C goals, the researchers emphasized that these time in range targets should be individualized, as nothing in diabetes is “one-size-fits-all.” Most important, however, the experts highlighted that even a 5% daily change in time in range – about one hour per day – is meaningful. See Adam Brown’s five key tips for spending more time in range here.
Implementing Time in Range into Clinical Guidelines:
In August 2019, ADA updated its Standards of Care to include the time in range targets – a groundbreaking moment that helped propel the movement forward. ADA’s Standards of Care dictate clinical diabetes care and influence other key stakeholders, such as insurers. The update, issued only two months after publication of the time in range targets consensus report, provided validity to time in range and its importance in diabetes management. Although use of CGM and time in range lags behind clinical guidelines, this addition was critical in expanding awareness of, and access to, these life-saving tools.
Further Momentum on Time in Range:
The 2019 meeting, and subsequent publication, helped advance time in range among diabetes researchers, clinicians, and advocates, as well as people with diabetes in their own self-management. Highlights include:
The number of scientific articles published in 2019 related to time in range quadrupled in comparison to 2018 (from about 20 to over 80), underscoring the increasing attention researchers are paying to this metric.
Abbott unveiled real-world CGM data from almost 500,000 FreeStyle Libre users, providing the largest population-level look at time in range. The data show that median time in range was 56%, and people who scanned more frequently showed greater time in range. This opened up exciting opportunities to understand where people with diabetes stand in glycemic management and which tools are effective in improving time in range.
IQVIA, a healthcare consulting firm, published a paper that establishes the considerable cost savings that improving time in range may bring. A conservative estimate predicts that if the average time in range for people with diabetes in the US increases to 70%, healthcare costs will be reduced by at least $2-$4 billion over ten years. The paper is important in underscoring the clinical and economic need to expand the use of both CGM and time in range.
At ATTD 2020 – one year after the 2019 landmark meeting – diaTribe convened top researchers and key industry leaders to kick off the new global Time in Range Coalition. The Coalition seeks to help establish time in range as a common and essential metric of diabetes care and management. The formation of the group and the commencement of its work demonstrated collaborative action toward that goal.
“The use of time in range has never been more relevant than now in the time of COVID-19,” Dr. Francine Kaufman explained. Given the increased need for and use of telehealth, time in range is a valuable tool for health care professionals and people with diabetes to assess diabetes management and to predict future risk in the absence of an A1C lab test. As Dr. Kaufman says, “Both time in range and telehealth are here to stay, as they have transformed diabetes care.”
The diaTribe Foundation is dedicated to making 2020, and every year beyond, the year of time in range.
This article is part of a series on time in range.
The diaTribe Foundation, in concert with the Time in Range Coalition, is committed to helping people with diabetes and their caregivers understand time in range to maximize patients' health. Learn more about the Time in Range Coalition here.