Continuous Glucose Sensor Survival and Accuracy Over 14 Consecutive Days

Continuous glucose monitoring (CGM) technology provides real-time glucose data and the ability to achieve improved glycemic control; however, widespread adoption has been limited (1). Among the challenges to CGMuptake are cost and the inconvenience of changing the sensor. In this prospective, multicenter study, theDexcomG4PLATINUMsystemwas analyzed over 14 days of continuous sensor wear. Each subject wore two sensors simultaneously. After 7 days, subjects left their original sensors in place and began a second 7-day sensor session. This procedure was then repeated with two new sensors for a second 2-week period. Blood glucose (BG) readings from Bayer CONTOUR NEXT meters served as reference (2), with absolute relative difference (ARD) defined as the percent error between sensor and matched BG values. The Mann-Whitney rank sum test was used for comparison of sensor accuracy for week 1 versus week 2. The data were analyzed in a generalized linear model to account for the within-patient correlation. Sensor survival is presented in Fig. 1 with Kaplan-Meier survival curves for failures due to adhesive failure and for all causes of failure. Sensor accuracy in Fig. 1 is presented asmedian (interquartile range [IQR] 25th, 75th centile). Fifty-seven subjects completed the study (46% male, mean 6 SD age 28.7 6 8.7 years and HbA1c 7.4 6 0.8% [57 6 6.6 mmol/mol]). In total, there were 222 2-week sensor sessions available for analysis, and 56% of sensors functioned for the full 2 weeks. Sensor failures occurred later in the 2-week period, and the main cause of sensor removal was related to failure of the tape adhesive (falling off or accidental dislodgment) (n 5 65, 29%). Only 10% of sensors were removed for “sensor failure” and 3% for “loss of signal.” Sensors tended to be well tolerated with minimal erythema or induration. There was one sensor site infection, which occurred on day 3.