Tsoukas M, Rutkowski J, El-Fathi A, Yale JF, Bernier-Twardy S, Bossy A, Pytka E, Legault L, Haidar A. Accuracy of FreeStyle Libre in Adults with Type 1 Diabetes: The Effect of Sensor Age.
Diabetes Technol Ther 2020;
22:203-207. [PMID:
31613140 DOI:
10.1089/dia.2019.0262]
[Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background: FreeStyle Libre is a factory-calibrated continuous 14-day glucose sensor. Little is known about the accuracy of FreeStyle Libre as a function of sensor age. Methods: We assessed the accuracy of FreeStyle Libre in 14 adults with type 1 diabetes. Each study participant attended our research facility for two or three 24-h visits, during which they wore a FreeStyle Libre aged 0-1 day, 5-7 days, or 13-14 days. Plasma glucose levels were measured every 10-30 min using YSI2300 STAT Plus Analyser. Participants also wore Dexcom G5® glucose sensor aged 1-2 days. We assessed sensors' accuracy using mean absolute relative difference (MARD) between FreeStyle Libre, the Dexcom G5 sensor, and plasma glucose. Results: We had 1930 pairs of FreeStyle Libre sensor-plasma glucose measurements, collected from 36 FreeStyle Libre sensors, 18 of which were sensors aged 0-1 day, 9 were sensors aged 5-7 days, and 9 were sensors aged 13-14 days. The mean and median MARD for FreeStyle Libre sensors aged 0-1 days were 14.5% and 11.2%, respectively, and for sensors aged 13-14 days were 14.7% and 11.2%, respectively, but for sensors aged 5-7 days were 7.8% and 6.6%, respectively (P = 0.03 vs. sensors aged 0-1 days, and P = 0.06 vs. sensors aged 13-14 days). The percentage of points falling in the potentially dangerous zones C, D, or E in Clarke's error grid analysis were 1.9% for FreeStyle Libre sensors aged 0-1 day, 0.2% for sensors aged 5-7 days, and 0.4% for sensors aged 13-14 days. The overall accuracy of FreeStyle Libre and Dexcom G5 sensor was the same (mean MARD 12.8% and 12.5%, respectively; P = 0.57). Conclusions: FreeStyle Libre's accuracy is adequate during its entire lifetime but is least accurate during its first and last days. ClinicalTrials.gov Identifier: NCT02814123.
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