Table 2.

Continuous Glucose Monitoring System Accuracy and Stability Within Yellow Springs Instruments Glucose Ranges

YSI glucose, range (mg/dL)	No. of paired CGM system-YSI reference readings	Percent within 15/15% reference	Percent within 20/20% reference	Percent within 30/30% reference	Percent within 40/40% reference	MARD (%) [95% CI]
Overall	16,653	85.7	93.3	98.1	99.4	8.8 (8.1–9.3)
>40–54	167	83.2	85.6	93.4	96.4	10.7 (7.4–13.3)
55–70	785	86.1	92.9	96.8	98.9	9.0 (8.1–12.0)
71–180	8943	84.8	92.3	97.5	99.2	8.7 (8.2–9.5)
>180	6758	86.9	95.0	99.0	99.8	7.8 (7.3–8.8)

In-clinic accuracy is assessed compared with venous YSI reference measurement. The percentage of system readings within ±15 mg/dL or 15% of YSI reference values (15/15%), ±20 mg/dL or 20% of YSI reference values (20/20%), ±30 mg/dL or 30% of YSI reference values (30/30%), or ±40 mg/dL or 40% of YSI reference values (40/40%) are reported. For YSI ≤70 mg/dL, the differences in mg/dL are included instead of percentage difference (%).

CGM, continuous glucose monitoring; CI, confidence interval; MARD, mean absolute relative difference; YSI, Yellow Springs Instruments.