Table 4:

Recommendations of the IFCC WG-CGM regarding the comparator measurement procedure in CGM performance evaluations.

Category	Recommendation
Comparator sampling frequency	Every 15 minutes for 6 to 8 hours [11]
Comparator glucose concentration distribution	At least 7.5% of all values each covering the following situations: [11] a) BG < 70 mg/dL b) BG > 300 mg/dL, c) BG ≥ 70 mg/dL, RoC < -1 mg/dL/min, BG < 70 mg/dL within 30 min at current RoC, and d) BG ≤ 300 mg/dL, RoC > +1.5 mg/dL/min, BG > 250 mg/dL within 30 min at current RoC
Comparator sample type	Capillary samples
Comparator bias	Bias ≤2.1% across measuring range vs. method (or material) of higher metrological order,[23] retrospective correction encouraged even if criterion is met
Comparator imprecision	CV ≤2.4% across measuring range [23]
Comparator replicates	≥2, to assess and reduce imprecision [27] and to detect outliers in participant samples

BG: blood glucose concentration, CGM: continuous glucose monitoring, CV: coefficient of Variation, IFCC WG-CGM: Working Group on Continuous Glucose Monitoring of the International Federation of Clinical Chemistry and Laboratory Medicine, RoC: rate of change