Performance Characteristics - Freestyle Libre 14 day User Manual

Performance Characteristics

Clinical Study Overview
Performance of the FreeStyle Libre 14 day Flash Glucose Monitoring System (the System) was
evaluated in a clinical study. The study was conducted at 4 centers with a total of 95 subjects with
diabetes (84.2% Type 1, 15.8% Type 2). All subjects were aged eighteen and older. Subjects in the
study required insulin to manage their diabetes. Each subject wore up to two Sensors on the back
of the upper arm. During the study, subjects tested their blood glucose using fingerstick capillary
samples at least eight times during each day of the study. Subjects used the blood glucose meter
built into the Reader. Additionally, subjects had their venous blood glucose analyzed up to 112 times
over four separate visits to the clinical center. Venous blood was analyzed using the Yellow Springs
Instrument Life Sciences 2300 STAT Plus™ Glucose & Lactate Analyzer (YSI). YSI is a laboratory glucose
and lactate analyzer of whole blood and plasma and is a widely recognized standard in laboratory
analysis of blood glucose. Glucose readings obtained from the System were compared to glucose
readings obtained from the YSI to evaluate the performance of the System. Three lots of Sensors
were evaluated in the study.
Agreement with YSI Levels
Agreement between the System Glucose Measurement (CGM) and venous blood was characterized by
using paired CGM and Yellow Springs Instrument measurements (YSI). The accuracy of CGM versus YSI
reference was assessed by calculating the percentage of System readings that were within 15%, 20%,
30% and 40% for reference values 80 mg/dL and above, and 15 mg/dL, 20 mg/dL, 30 mg/dL and
40 mg/dL for values below 80 mg/dL when glucose levels are assigned using the YSI values. Overall
90.7% of results were within ±20 mg/dL / 20% of YSI reference.
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