UNDERSTANDING Time in Range

“Time in Range” (TIR) is a clinical metric showing the percentage of time a person with diabetes (PWD) spends within their established glycemic target levels. The range will vary depending on the person, but internationally established guidelines often mean a range of 70 to 180 mg/dl. 

TIR metrics include five levels. Beginning with Time in Range, the goal is to have a PWD spend 70%+ or 17 hours of his/her day between 70 to 180 mg/dl. Times Below Range (TBR) encompass level 1 hypoglycemia (70-55 mg/dl) designated as TBR Low and level 2 hypoglycemia (54 mg/dl and below) as TBR Very Low. People with diabetes ideally will spend less than 4% (or 1 hour) in these TBR levels. Times Above Range (TAR) capture Hyperglycemic levels of 181-250 mg/dl within TAR High and above 250 as TAR Very High. Clinical guidance encourages less than 25% or six hours to be spent in these TAR levels.

Time in Range is most commonly measured by continuous glucose monitoring (CGM).

Why Is Time in Range Data Important (dQ&A 2021 research for TIRC) 

• TIR provides better, more timely information
• Captures glucose variability
• Informs more focused decisions
• Helps to individualize care

Time in range is not just for treatment decisions, surveyed HCPs reported that: 

• 80% use it for educating patients
• 72% use it to motivate patients
• 70% use it to increase patient engagement in their own care

In their 2023 Standards of Care (SOC) in Diabetes 2023, the American Diabetes Association recommends that continuous glucose monitoring be offered for diabetes management in children and adults with diabetes on insulin (7. Diabetes Technology: Standards of Care in Diabetes—2023, Diabetes Care 2023;46(Suppl. 1):S111–S127, https://doi.org/10.2337/dc23-S007)  The SOC also acknowledges that time in range (TIR) is a “useful metric of glycemic control and glucose patterns, and it correlates well with A1C in most studies (24–29). New data support the premise that increased TIR correlates with the risk of complications.”

In 2021, the New England Journal of Medicine reported that only 50.5% of people with diabetes in the US were achieving an A1c level that would correlate with reduced complications. People with diabetes and their healthcare teams need more information to make clinical decisions to improve these outcomes. 

Time in Range is a complement to A1C’s average 2-3 month glucose measurement for reducing complication risks, because it captures time spent in various blood glucose ranges throughout the day as opposed to an average overtime.

To illustrate the limitations of A1C and the advantages of Time in Range, see the graphic below that shows three different PWD – all with the same average glucose (154 mg/dl) and the same A1C (7%). However, time spent with high, low, and in-range blood glucose values are markedly different: the first person has a rollercoaster of dangerous highs and lows, the second has moderate variability with fewer highs and lows, and the third person has little variability with all time spent in-range.

Anyone with diabetes.

Time in Range is a new way for anyone to manage their glycemic levels to improve their outcomes. TIR captures daily glucose variability as well as behavioral cause-and-effect information. This information helps to inform decisions and individualize care. Research conducted by dQ&A showed that: 

• 80% of HCPs used TIR to educate patients
• 72% of HCPs used TIR to motivate patients
• 70% of HCPs used TIR to increase patient engagement in their own care