Clinical Medicine Insights: Endocrinology and Diabetes · Published 2026-07-01 · DOI 10.1177/11795514261470879
Miguel Aguilar-Schotborgh, Oscar Mauricio Muñoz-Velandia, Diana Cristina Henao-Carrillo, Luis Triana Moreno, Jhon Moreno Mogollon, Ana Maria Gómez
Background The accuracy of the FreeStyle Libre 2 system in critically ill patients needing insulin therapy remains inadequately evaluated. Objective To evaluate the clinical and numerical accuracy of continuous glucose monitoring (FreeStyle Libre 2) and capillary glucometry (StatStrip) compared with central laboratory glucose in critically ill patients requiring insulin therapy. Methods We conducted a diagnostic accuracy study, evaluating simultaneously two index tests, the FreeStyle Libre 2 and capillary glucose, compared to the central laboratory glucose (venous or arterial) as reference standard. The study included critically ill adult patients admitted to the intensive care unit (ICU) with diabetes or stress hyperglycemia, requiring insulin therapy, and ventilatory or vasopressor support. Numerical accuracy was assessed using ISO 15197:2013 criteria and Mean Absolute Relative Difference (MARD). Clinical accuracy was evaluated using Clarke and Parkes error grid analysis. Results A total of 157 paired measurements were collected. FreeStyle Libre 2 showed a MARD comparable to capillary glucose (10.43% vs 7.58%; p=0.14). Neither method met ISO 15197:2013 numerical accuracy criteria. In the clinical accuracy analysis, FreeStyle Libre 2 classified 100% of measurements within zones A+B on both the Clarke and Parkes grids, whereas capillary glucose achieved 97.6% and 100%, respectively. Conclusions FreeStyle Libre 2 showed numerical accuracy comparable to capillary blood glucose and consistently reliable clinical performance in critically ill patients needing insulin therapy. These results support its potential as an alternative to capillary glucose monitoring in the ICU. More studies involving a greater number of hypoglycaemic events are required to confirm its effectiveness in this critical range.
Abstract from DOAJ. Public domain (CC0 1.0).
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Aguilar-Schotborgh, M., Muñoz-Velandia, O., Henao-Carrillo, D., et al. (2026). Numerical and Clinical Accuracy of the FreeStyle Libre 2 System: A Diagnostic Accuracy Study in Critically Ill Patients. Clinical Medicine Insights: Endocrinology and Diabetes. https://doi.org/10.1177/11795514261470879