Table 3.
Stepped Approach to CGM Data Review and Interpretation.
| Whenever Possible Compare with Previous Data to Assess Glucometrics Changes | |
|---|---|
| CGM key metric for data analysis | Targets, action |
| Data sufficiency | 10-14 days54 |
| CGM use | >70%58 |
| Sensor glucose average—glucose exposure | Mean glucose values over the preceding 2 weeks |
| Glycemic variability (GV) • Coefficient of variation (CV) • Standard deviation (SD) |
<36%55
<33% of mean sensor glucose value56 |
| Percentage of time in target range (70-180 mg/dL) | >70%59 |
| Percentage of time in hypoglycemia • Level 1 (<70-54 mg/dL) • Level 2 (<54 mg/dL) |
<3%51
- Alert, monitor - Clinically significant, immediate action required |
| Percentage of time in hyperglycemia • Level 1 (>180 mg/dL) • Level 2 (>250 mg/dL) |
<25%58
- Alert, monitor - Clinically significant, immediate action required |
| AGP graphs | - Identify hypoglycemia patterns time of day/night (10th
percentile <70 mg/dL or <54 mg/dL) - Identify hyperglycemia patterns time of day/night (90th percentile >250 mg/dL) - Identify areas of greater GV (wider “cloud” or “ribbon”—25th-75th percentile) - Identify time of day with recurrent patterns (smaller width of the “cloud” or “ribbon”) - Determine if hypo/hyperglycemia is caused by basal rates/basal insulin dose - Identify mealtime patterns and glycemic excursions |
| CGM daily view—modal day view and/or integrated insulin pump/CGM daily views | Hypoglycemia - Identify nocturnal hypoglycemia and assess whether this is isolated or recurrent - Monitor for weekdays vs weekends hypoglycemia - Verify or obtain information from patient to assess contributors of nocturnal hypoglycemia - Basal rates or long acting insulin dose - Physical activity, type, duration, and time of day - Alcohol intake - Other evening activities - Identify daytime pre- or postprandial hypoglycemia - Verify or obtain information from patient to assess contributors of daytime hypoglycemia - Physical activity, type, duration, and time of day - Meal times or missed meal after insulin dosing - Meal quality (high or low glycemic index) - Insulin dosing times - Insulin to carbohydrate ratio - Insulin sensitivity factor (or correction factor) - Insulin stacking from aggressive use of correction dose Hyperglycemia - Identify daytime pre-, postprandial, and nocturnal hyperglycemia - Monitor for weekdays vs weekends hyperglycemia - Obtain information from patient to assess contributors - Meal times - Missed mealtime insulin dose - Meal quality (high or low glycemic index) - Insulin dosing times - Insulin to carbohydrate ratio - Insulin sensitivity factor (or correction factor) - Basal rates or long acting insulin dose - Prolonged use of temporary basal or suspension of insulin delivery - Possible insulin pump site failure |