Intermittently Scanned and Real-Time Continuous Glucose Monitoring for People With Diabetes


Project Status:
Project Line:
Health Technology Review
Project Sub Line:
Rapid Review
Project Number:


  1. What is the comparative clinical effectiveness of monitoring glycemia with intermittently scanned continuous glucose monitoring versus real-time continuous glucose monitoring in people with diabetes?

Key Message

Continuous glucose monitoring is a method of glucose testing in which a sensor is inserted into the skin and continuously monitors interstitial glucose concentrations. Real-time continuous glucose monitoring (rtCGM) systems automatically measure glucose and display a recent glucose value. Intermittently scanned continuous glucose monitoring (isCGM) systems require the person using the system to scan the sensor to display glucose information. The evidence of the comparative effectiveness of isCGM versus rtCGM for improving time in range, time above range, A1C, and quality of life in people with type 1 diabetes is uncertain. Evidence from some studies suggested there was a significant benefit favouring rtCGM versus isCGM for these outcomes, whereas other studies found no significant differences between treatment groups. Evidence suggested that people with type 1 diabetes using rtCGM spent significantly less time below range/time in hypoglycemia than those using isCGM. The evidence of the comparative safety of isCGM versus rtCGM in people with type 1 diabetes is limited and uncertain. Evidence from 1 study suggested that severe hypoglycemic events were more frequent in those using isCGM. In other studies, there were no severe hypoglycemic events in either treatment group. No studies were identified that evaluated the comparative effectiveness of isCGM versus rtCGM in people living with type 2 diabetes or gestational diabetes.