In recent years, with the continuous maturation of fingerstick-calibration-free continuous glucose monitoring (CGM) systems, especially the promotion and application of high-standard integrated CGM (iCGM), glucose monitoring technology is advancing toward a new stage of greater precision.
CGM helps people with diabetes better manage their condition. However, different CGM systems vary in clinical outcomes and patient safety.Mean Absolute Relative Difference (MARD), as a core indicator for evaluating the accuracy of traditional CGM, reflects the average discrepancy between sensor readings and reference values.Yet MARD is estimated in clinical studies, is susceptible to multiple influencing factors, and has certain limitations in application.
To assess CGM accuracy more comprehensively and objectively, the U.S. Food and Drug Administration (FDA) took the lead in proposing the iCGM standard.This standard focuses on the distribution of individual readings and requires robust clinical data to ensure reliable clinical accuracy across the full glucose range, with special emphasis on performance in critical glucose ranges such as hypoglycemia and hyperglycemia.
The iCGM standard imposes stringent performance requirements, covering 13 key performance indicators (9 of which have been adopted by the National Medical Products Administration (NMPA) of China), and sets specific accuracy thresholds for different glucose ranges: hypoglycemia, euglycemia, and hyperglycemia.
Studies have shown that iCGM demonstrates high accuracy in both adult and pediatric patients, particularly in the hypoglycemic range, and maintains high accuracy throughout a 14-day wear period.
Meanwhile, the hypo‑ and hyperglycemia alert functions of iCGM systems feature high sensitivity and high specificity, effectively reducing the risks of false and missed alerts.In terms of safety, iCGM does not contain isobornyl acrylate (IBOA), resulting in a low incidence of allergic reactions.It is also compatible with various medical imaging examinations including X‑ray, CT, and MRI, making it a preferred choice for CGM use in hospital settings.