New clinical opinion proposes pathway towards “internationally interpretable” CGM evaluation
A modified Delphi process involving clinicians, scientists and researchers identified three barriers currently constraining reliable interpretation of glucose-derived measures.
As continuous glucose monitoring (CGM) becomes increasingly integral to diabetes management, differences in the evaluation of medical devices continue to hinder robust and meaningful comparisons between CGM systems.
The first barrier identified is limited transparency. In several regulatory settings, particularly those using Conformité Européenne marking, clinical-study reports, reference-method information and analytical documentation required for market authorisation are not publicly accessible.
The second barrier is heterogeneity in study procedures. Existing evaluations use different reference-glucose methods, sampling strategies, glucose-manipulation protocols and participant characteristics, leading to accuracy estimates that cannot be interpreted consistently across systems.
A final barrier is calibration alignment. Although evaluation processes may be transparent and standardised, CGM systems can still diverge in performance because their calibration algorithms are based on different reference glucose datasets. These foundational discrepancies can influence reported glucose profiles, alter automated insulin delivery behaviour and affect how readings are interpreted when people move between devices.
According to the international clinical opinion, these steps provide a foundation for reliable interpretation and globally comparable assessment of CGM technologies.
During this process, the International Federation of Clinical Chemistry and Laboratory Medicine also released a validated framework for performance evaluation of CGM systems, providing a unified approach to reference-method selection, dynamic in-clinic testing and structured reporting.
While adoption helps standardise procedures and reduce variability, experts emphasise that it would still leave calibration-alignment differences unresolved.
The study stated: “This international clinical opinion proposes a pathway towards internationally interpretable CGM evaluation: immediate transparency of clinical evidence, routine declaration of calibration alignment and progressive adoption of validated standardised procedures.”
To access the international clinical opinion, click here.