The Performance and Usability of a Factory-Calibrated Flash Glucose Monitoring System

Timothy Bailey, Bruce W Bode, Mark P Christiansen, Leslie J Klaff, Shridhara Alva, Timothy Bailey, Bruce W Bode, Mark P Christiansen, Leslie J Klaff, Shridhara Alva

Abstract

Introduction: The purpose of the study was to evaluate the performance and usability of the FreeStyle(®) Libre™ Flash glucose monitoring system (Abbott Diabetes Care, Alameda, CA) for interstitial glucose results compared with capillary blood glucose results.

Materials and methods: Seventy-two study participants with type 1 or type 2 diabetes were enrolled by four U.S. clinical sites. A sensor was inserted on the back of each upper arm for up to 14 days. Three factory-only calibrated sensor lots were used in the study. Sensor glucose measurements were compared with capillary blood glucose (BG) results (approximately eight per day) obtained using the BG meter built into the reader (BG reference) and with the YSI analyzer (Yellow Springs Instrument, Yellow Springs, OH) reference tests at three clinic visits (32 samples per visit). Sensor readings were masked to the participants.

Results: The accuracy of the results was demonstrated against capillary BG reference values, with 86.7% of sensor results within Consensus Error Grid Zone A. The percentage of readings within Consensus Error Grid Zone A on Days 2, 7, and 14 was 88.4%, 89.2%, and 85.2%, respectively. The overall mean absolute relative difference was 11.4%. The mean lag time between sensor and YSI reference values was 4.5±4.8 min. Sensor accuracy was not affected by factors such as body mass index, age, type of diabetes, clinical site, insulin administration, or hemoglobin A1c.

Conclusions: Interstitial glucose measurements with the FreeStyle Libre system were found to be accurate compared with capillary BG reference values, with accuracy remaining stable over 14 days of wear and unaffected by patient characteristics.

Trial registration: ClinicalTrials.gov NCT02073058.

Figures

FIG. 1.
FIG. 1.
(Left panel) Consensus and (right panel) Clarke Error Grid Analysis comparing the FreeStyle Libre sensor readings with capillary blood glucose reference values using the FreeStyle Precision meter built into the Reader.
FIG. 2.
FIG. 2.
Histogram of the mean absolute relative difference (MARD) per sensor.
FIG. 3.
FIG. 3.
Stability of accuracy across 14 days of Freestyle Libre sensor wear: Consensus Error Grid Zone A (green), Zone B (blue), and Zone C (red). N is the number of paired sensor and reference data points per day of wear for all sensors used in the study.
FIG. 4.
FIG. 4.
Accuracy of the FreeStyle Libre sensor as a function of various factors or patient characteristics: (A) diabetes type, (B) sex, (C) insertion site, (D) insulin administration (Insulin Ad) (continuous subcutaneous insulin infusion [CSII] or multiple daily insulin injections [MDI]), (E) body mass index (BMI), (F) hemoglobin A1c (HbA1c), (G) age, and (H) rate of change. Consensus Error Grid zones were Zone A (green), Zone B (blue), and Zone C (red).

References

    1. Freckmann G, Pleus S, Link M, Zshornack E, Klotzer H, Haug C: Performance evaluation of three continuous glucose monitoring systems: comparison of six sensors per subject in parallel. J Diabetes Sci Techol 2013;7:842–853
    1. Pfützner A, Mitri M, Musholt PB, Sachsenheimer D, Borchert M, Yap A, Forst T: Clinical assessment of the accuracy of blood glucose measurement devices. Curr Med Res Opin 2012;28:525–531
    1. Freckmann G, Baumstark A, Schmid C, Pleus S, Link M, Haug C: Evaluation of 12 blood glucose monitoring systems for self-testing: system accuracy and measurement reproducibility. Diabetes Technol Ther 2014;16:113–122
    1. Klaff LJ, Brazg R, Hughes K, Tideman AM, Schachner HC, Stenger P, Pardo S, Dunne N, Parkes JL: Accuracy evaluation of Contour Next compared with five blood glucose monitoring systems across a wide range of blood glucose concentrations occurring in a clinical research setting. Diabetes Technol Ther 2015;17:8–15
    1. Thomas LE, Kane MP, Bakst G, Busch RS, Hamilton RA, Abelseth JM: A glucose meter accuracy and precision comparison: the FreeStyle Flash versus the Accu-Chek Advantage, Accu-Chek Compact Plus, Ascensia Contour, and the BD Logic. Diabetes Technol Ther 2008;10:102–110
    1. Damiano E, El-Khatib F, Zheng H, Nathan D, Russell S: A comparative effectiveness analysis of three continuous glucose monitors. Diabetes Care 2013;36:251–259
    1. Damiano E, McKeon K, El-Khatib F, Zheng H, Nathan D, Russell S: A comparative effectiveness analysis of three continuous glucose monitors: the Navigator, G4 Platinum, and Enlite. J Diabetes Sci Technol 2014;8:699–708
    1. Matuleviciene V, Joseph J, Andelin M, Hirsch I, Attvall S, Pivodic A, Dahlqvist , Klonoff D, Haraldsson B, Lind M: A clinical trial of the accuracy and treatment experience of the Dexcom G4 sensor (Dexcom G4 system) and Enlite sensor (Guardian REAL-Time system) tested simultaneously in ambulatory patients with type 1 diabetes. Diabetes Technol Ther 2014;16:759–767
    1. Kuwa K, Nakayama T, Hoshino T, Tominaga M: Relationships of glucose concentrations in capillary whole blood, venous whole blood and venous plasma. Clin Chim Acta 2001;307:187–192
    1. Tonyushkina K, Nichols JH: Glucose meters: a review of technical challenges to obtaining accurate results. J Diabetes Sci Technol 2009;3:971–980
    1. Shivers JP, Mackowiak L, Anhalt H, Zisser H. “Turn it off!”: diabetes device alarm fatigue considerations for the present and the future. J Diabetes Sci Technol 2013;7:789–794
    1. Rossetti P, Bondia J, Vehí J, Fanelli CG: Estimating plasma glucose from interstitial glucose: the issue of calibration algorithms in commercial continuous glucose monitoring devices. Sensors (Basel) 2010;10:10936–10952
    1. New JP, Ajjan R, Pfeiffer AFH, Freckmann G: Continuous glucose monitoring in people with diabetes: the randomized controlled Glucose Level Awareness in Diabetes Study (GLADIS). Diabet Med 2015;32:609–617
    1. Rebrin K, Sheppard NF, Jr, Steil GM: Use of subcutaneous interstitial fluid glucose to estimate blood glucose: revisiting delay and sensor offset. J Diabetes Sci Technol 2010;4:1087–1098
    1. Castle JR, Ward WK: Amperometric glucose sensors: sources of error and potential benefit of redundancy. J Diabetes Sci Technol 2010;4:221–225
    1. Mazze RS, Strock E, Borgman S, Wesley D, Stout P, Racchini J: Evaluating the accuracy, reliability, and clinical applicability of continuous glucose monitoring (CGM): is CGM ready for real time? Diabetes Technol Ther 2009;11:11–18
    1. Bailey T, Zisser H, Chang A: New features and performance of a next-generation SEVEN-day continuous glucose monitoring system with short lag time. Diabetes Technol Ther 2009;11:749–755
    1. Michaud C, Cengiz E, Tamborlane WV, Carria LR, Weinzimer SA: Warming up to sensors: does site warming improve continuous glucose monitoring performance? [abstract]. Diabetes 2014;63(Suppl 1):870-P
    1. Cengiz E, Tamborlane VW: A tale of two compartments: interstitial versus blood glucose monitoring. Diabetes Technol Ther 2009;11(Suppl 1):S-11–S-16
    1. Lodwig V, Heinemann L; Glucose Monitoring Study Group: Continuous glucose monitoring with glucose assessment criteria. Diabetes Technol Ther 2003;5:572–586
    1. Kempe K, Price D, Ellison J, Marhoul J, Morrow L, Win K, Kuschma K, Hompesch M: Capillary and venous blood glucose concentrations measured during intravenous insulin and glucose infusion: a comparison of steady and dynamic states. Diabetes Technol Ther 2009;11:669–674
    1. Colaguri S, Sandbaek A, Carstensen B, Christensen J, Glumert C, Lauritzen T, Borch-Johnsen K: Comparability of venous and capillary glucose measurements in blood. Diabet Med 2003;20:953–956
    1. Clinical and Laboratory Standards Institute: Glucose Monitoring in Settings Without Laboratory Support; Approved Guideline—Second Edition. CLSI document AST4-A2 Wayne, PA: Clinical and Laboratory Standards Institute, 2005
    1. Hoss U, Budiman ES, Liu H, Christiansen MP: Continuous glucose monitoring in the subcutaneous tissue over a 14-day sensor wear period. J Diabetes Sci Technol 2013;7:1210–1219
    1. Hoss U, Budiman ES, Liu H, Christiansen MP: Feasibility of factory calibration for subcutaneous glucose sensors in subjects with diabetes. J Diabetes Sci Technol 2014;8:89–94
    1. Ward KW: A review of the foreign-body response to subcutaneously-implanted devices: the role of macrophages and cytokines in biofouling and fibrosis. J Diabetes Sci Technol 2008;2:768–777
    1. Weinstein RL, Schwartz SL, Brazg RL, Bugler JR, Peyser A, McGarraugh GV: Accuracy of the 5-Day FreeStyle Navigator continuous glucose monitoring system. Diabetes Care 2007;30:1125–1130
    1. JDRF Continuous Glucose Monitoring Study Group: The effect of continuous glucose monitoring in well-controlled type 1 diabetes. Diabetes Care 2009;32:1378–1383
    1. Danne T, de Valk HW, Kracht KW, Geldmacher R, Sölter L, von dem Berge W, Welsh ZK, Bugler JR, Lange K, Kordonouri O: Reducing glycaemic variability in type 1 diabetes self-management with a continuous glucose monitoring system based on wired enzyme technology. Diabetologia 2009;52:1496–1503
    1. Hirsch IB, Abelseth J, Bode BW, Fischer JS, Kaufman FR, Mastrototaro J, Parkin CG, Wolpert HA, Buckingham BA: Sensor-augmented insulin pump therapy: Results of the first randomized treat-to-target study STAR-1. Diabetes Technol Ther 2008;10:377–383
    1. Bergenstal RM, Tamborlane WV, Ahmann A, Buse JB, Dailey G, Davis SN, Joyce C, Peoples T, Perkins BA, Welsh JB, Willi SM, Wood MA; STAR 3 Study Group: Effectiveness of sensor-augmented insulin-pump therapy in type 1 diabetes. N Engl J Med 2010;363:311–320. Erratum in N Engl J Med 2010;363:1092
    1. Battelino T, Phillip M, Bratina N, Nimri R, Oskarsson P, Bolinder J: Effect of continuous glucose monitoring on hypoglycemia in type 1 diabetes. Diabetes Care 2011;34:795–800

Source: PubMed

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