Three factory-calibrated production sensor lots were used for the study. Study participants inserted and wore the sensor on the back of each upper arm (two sensors total), without any overbandage, for up to 14 days. The protocol and informed consent forms were approved by a central Institutional Review Board, and all subjects provided written informed consent before enrollment in the study. This prospective, single-arm, clinical study was conducted at four U.S. Performance against the venous blood reference is provided for comparison. The objective of this article is to describe the performance and usability of the System by comparing its scanned sensor results with capillary BG values measured using the built-in BG meter. The System displays trends and alerts on the Reader but does not have real-time alarms, which may provide a good option for individuals who complain of alarm fatigue. The BG readings on the built-in meter are independent of, and do not influence, sensor readings. The hand-held reader with the built-in FreeStyle Precision BG meter is used to scan the sensor to receive a glucose result along with historic results with a 15-min frequency for up to 8 h.
Freestyle libre flash glucose monitoring system patches Patch#
11, 12 The entire System's on-body sensor patch worn on the back of the upper arm is disposable after use. This feature differs from existing sensors, which require multiple fingerstick BG measurements over the life of the sensor for calibration. The wired enzyme sensor is calibrated in the factory and therefore requires no user calibration during 14 days of wear. The System has several features that distinguish it from existing sensor technology. Additionally, capillary BG provides more reference points and represents real-life accuracy during daily patient use. Therefore, capillary BG may be considered an appropriate comparator in evaluating the performance and accuracy of this factory-only calibrated System. 9, 10 The FreeStyle ® Libre™ Flash glucose monitoring system (Abbott Diabetes Care, Alameda, CA), hereafter referred to as the “System,” is an interstitial glucose monitoring system intended to be a replacement for the capillary BG measurement. 6–8 Glucose concentrations between the capillary and venous samples differ, and therefore the sample type used for calibration versus reference measurement may influence the results of an accuracy evaluation.
1–5 Clinical laboratories use venous samples analyzed using a laboratory analyzer, whereas lay users use capillary BG measurements measured using a glucose meter for the calibration of sensors. Sensor accuracy was not affected by factors such as body mass index, age, type of diabetes, clinical site, insulin administration, or hemoglobin A1c.Ĭonclusions: 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.Ĭ apillary and venous blood glucose (BG) values are typically used as reference to evaluate the accuracy of in vivo sensor devices. The mean lag time between sensor and YSI reference values was 4.5±4.8 min. The overall mean absolute relative difference was 11.4%. 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. 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.
Sensor readings were masked to the participants. 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). Three factory-only calibrated sensor lots were used in the study. A sensor was inserted on the back of each upper arm for up to 14 days.
Materials and Methods: Seventy-two study participants with type 1 or type 2 diabetes were enrolled by four U.S. 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.