Table 1

Key features of current stand-alone rtCGM and isCGM devices

FeatureisCGMrtCGM
FreeStyle Libre (36,37)Dexcom G6 (39)Dexcom G5 (38)*Guardian 3 (40)Enlite (41)Eversense (65)
Minimum age for use, years≥18 (U.S.)≥2≥2≥7≥16≥18
≥4 (ex-U.S.)
Indicated for use in pregnancyNo (U.S.)NoNoNoNoNo
Yes (ex-U.S.)
Sensor wear time, days10 (U.S.)ƒ10776≤90 (U.S.)
14 (ex-U.S.)≤180 (ex-U.S.)
Calibration with SMBG is requiredNoNo2×/day2×/day2×/day2×/day
Allows optional calibrationNoYesYesYesYesYes
Warm-up period, h12 (U.S.)ƒ222224 (only upon insertion of sensor)
1 (ex-U.S.)
Insulin dosing approved without confirmatory fingerstick testingYesYesYesNoNoNo
Provides trend arrowsYesYesYesYesYesYes
Provides active alarms/alerts for current and impending hyperglycemia and hypoglycemiaNoYesYesYesYesYes
Real-time remote monitoring (data sharing)NoYesYesNoYesYes
Connects with insulin pumpNoYesYesYesYesNo
Interoperability with other devicesNoYesYesNoYesYes
Accuracy: overall
 MARD, %9.7 (66)9.0 (39)9.0 (38)10.6 (67)16.1 (68)8.8 (65)
Accuracy: low glucose range
 MARD, % [range, mg/dL]24.0 [≤70] (69)9.4 [61–80] (67)13.0 [61–80] (68)9.0 [55–70] (65)
 MAD, mg/dL§ [range, mg/dL]13.0 [≤70] (69)11.5 [54–69] (39)6.7 [61–80] (38)
  • Numbers in parentheses are references. ex-U.S., outside the U.S.

  • *Results are from assessment of the Dexcom G4 sensor with Software 505, which is used in the Dexcom G5 system.

  • †Mean absolute relative difference (MARD) between sensor readings and reference values, expressed as %.

  • ‡Derived from twice-daily calibration; Guardian 3 accuracy is improved with 3–4 calibrations per day (9.7%).

  • §Mean absolute difference (MAD) between sensor readings and reference values, expressed as mg/dL.

  • ƒRecently approved in the U.S. for 14-day wear and 1-h warm-up period. Not currently available at the time of this publication.