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Consensus Error Grid Analysis
Error grids evaluate CGM clinical accuracy by plotting sensor readings against reference values and categorizing deviations by clinical risk level.
Consensus Error Grid Analysis
Evaluating Clinical Accuracy
Error grids provide a visual and quantitative method to evaluate CGM accuracy beyond simple MARD calculations.
How Error Grids Work
CGM readings are plotted against reference blood glucose levels on a graph. The graph is divided into zones indicating the level of clinical risk.
The Five Zones
Zone A: Clinically Accurate
- No risk
- Minimal deviation
- Values would lead to correct treatment decisions
Zone B: Benign Errors
- Low risk
- Slight deviation
- Values would lead to benign or no treatment
Zone C: Overcorrection Zone
- Moderate risk
- More significant deviation
- Values could lead to unnecessary treatment
Zone D: Failure to Detect
- High risk
- Large deviation
- Values could lead to failure to detect hypo/hyperglycemia
Zone E: Dangerous
- Extreme risk
- Very large deviation
- Values could lead to opposite treatment from needed
Regulatory Importance
FDA iCGM standards require specific percentages of readings to fall within Zones A and B for device approval.