Accuracy of the 5-Day FreeStyle Navigator Continuous Glucose Monitoring System

Abstract

OBJECTIVE -The purpose of this study was to compare the accuracy of measurements of glucose in interstitial fluid made with the FreeStyle Navigator Continuous Glucose Monitoring System with Yellow Springs Instrument laboratory reference measurements of venous blood glucose.RESEARCH DESIGN AND METHODS -Fifty-eight subjects with type 1 diabetes, aged 18 -64 years, were enrolled in a multicenter, prospective, single-arm study. Each subject wore two sensors simultaneously, which were calibrated with capillary fingerstick measurements at 10, 12, 24, and 72 h after insertion. Measurements from the FreeStyle Navigator system were collected at 1-min intervals and compared with venous measurements taken once every 15 min for 50 h over the 5-day period of sensor wear in an in-patient clinical research center. Periods of high rates of change of glucose were induced by insulin and glucose challenges. RESULTS -Comparison of the FreeStyle Navigator measurements with the laboratory ref-erence method (n ϭ 20,362) gave mean and median absolute relative differences (ARDs) of 12.8 and 9.3%, respectively. The percentage in the clinically accurate Clarke error grid A zone was 81.7% and that in the in the benign error B zone was 16.7%. During low rates of change (ϽϮ1 mg ⅐ dl Ϫ1 ⅐ min Ϫ1 ), the percentage in the A zone was higher (84.9%) and the mean and median ARDs were lower (11.7 and 8.5%, respectively).CONCLUSIONS -Measurements with the FreeStyle Navigator system were found to be consistent and accurate compared with venous measurements made using a laboratory reference method over 5 days of sensor wear (82.5% in the A zone on day 1 and 80.9% on day 5).

Continuous Glucose Monitoring System in children with type 1 diabetes mellitus: a systematic review and meta-analysis

“…Table 1 summarises characteristics of the included trials. Five RCTs involving 131 participants met our predefined inclusion criteria [15][16][17][18][19]; the remaining 20 studies were excluded [7,[11][12][13][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Table 2 summarises the characteristics of excluded trials, including reasons for exclusion.…”

“…Real-Time glucose sensing system used Chase et al [23] RCT; GlucoWatch G2 Biographer used Chico et al [24] Non-randomised, uncontrolled trial Deiss et al [25] Non-randomised, uncontrolled trial Deiss et al [26] RCT; Guardian RT system used DirectNet [27] RCT; GlucoWatch G2 Biographer used DirectNet [28] RCT; GlucoWatch G2 Biographer used Fiallo-Scharer et al [29] RCT; GlucoWatch G2 Biographer used Garg et al [30] RCT; DexCom STS system used Halvorson et al [31] Non-randomised, uncontrolled trial. Paradigm Real-Time system used Kaufman et al [11] Non-randomised, uncontrolled trial Salardi et al [12] Non-randomised, uncontrolled trial Schaepelynck-Belicar et al [13] Non-randomised, uncontrolled trial Tanenberg et al [32] Randomised controlled trial performed in adults Tansey et al [33] Non-randomised study; did not report any of our defined outcomes Weinstein et al [34] Non-randomised, uncontrolled trial. FreeStyle Navigator system used Wilson et al [35] Non-randomised, uncontrolled trial.…”

Performance Evaluation of Three Continuous Glucose Monitoring Systems: Comparison of Six Sensors Per Subject in Parallel

“…With the Navigator and the Seven Plus, PARD seemed to slightly improve with sensor usage time. The performance of all systems within the hypoglycemic range (<70 mg/dl) was markedly lower than at higher glucose concentrations, a known fact 3,5,7,12,14,18 that is still dissatisfying for CGM users. While the Guardian achieved a slightly lower MARD than the Seven Plus, its PARD was slightly higher.…”

“…In 2008, the Clinical and Laboratory Standards Institute published POCT05-A, which provides recommendations for study design and parameters of interest in the performance evaluation of CGM systems. 1 Multiple studies investigating CGM systems were published over the years; [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] only one claimed to use procedures recommended in POCT05-A. 13 A comparison of these studies, however, is difficult due to variations in subject groups 11 and study design, including use of different devices for calibration of CGM systems and for reference measurements, either overall or for different study phases.…”

“…13 A comparison of these studies, however, is difficult due to variations in subject groups 11 and study design, including use of different devices for calibration of CGM systems and for reference measurements, either overall or for different study phases. [2][3][4][6][7][8][9][10]12,13,16,17 Given that comparability of different CGM systems is heavily influenced by these factors, it is thus improved when the different CGM systems are worn simultaneously by the same subjects under identical conditions (e.g., in head-to-head comparisons). There are studies in which different CGM systems were compared under such conditions, 2,7,12 but in these cases, only one sensor per CGM system was worn by the subjects.…”