Current intermittently scanned continuous glucose monitoring (isCGM) devices do not allow calibration and require confirmatory self-monitored blood glucose (SMBG) under specific defined conditions. The overall time spent in an SMBG-indicated state while using isCGM has not been reported in the existing literature. We present the time spent in an SMBG-indicated state and the daily number of transitions to an SMBG-indicated state during isCGM use in a high-risk cohort of adults with type 1 diabetes. This is a post hoc analysis of participants randomized to isCGM as part of a clinical study. The percentage of values meeting one or more of the criteria for SMBG testing (hours per day) and the number of transitions to an SMBG-indicated state per day were calculated according to the manufacturer's label in the United Kingdom. Complete data sets for 20 participants on isCGM for 8 weeks were included in the analysis. Participants spent a mean (SD) of 5.61 (1.81) h/day in an SMBG-indicated state and there were 5.43 (1.42) transitions to an SMBG-indicated state per day while using isCGM. These findings have important implications for cost-effectiveness and for decision-making around insulin dose calculations and driving. Our findings emphasize the need for continued SMBG testing among people at high risk of hypoglycemia who use isCGM. Cost-effectiveness analyses for isCGM may require revision.
Keywords: Flash glucose monitoring; Hypoglycemia; Intermittently scanned continuous glucose monitoring; Type 1 diabetes.