Table 2.
Point accuracy – Euglycemia, 70 < BG < 180 mg/dl (3.9–10.0 mmol/liter)a | |||||||
---|---|---|---|---|---|---|---|
Guardian®b | DexCom STS®b | DexCom SEVEN PLUS®c | Navigator®b | GlucoDay®Sb | GlucoMen®Day | ||
Mean absolute error | mg/dl | 16.4 | 22.3 | n.a.d | 16.0 | 15.7 | 11.9 |
mmol/liter | 0.91 | 1.24 | n.a. | 0.89 | 0.87 | 0.66 | |
Mean absolute relative error (%) | 15.2 | 21.2 | 15.0 | 15.3 | 15.6 | 10.4 | |
Median absolute error | mg/dl | 14.8 | 19.1 | n.a. | 15.3 | 10.8 | 10.1 |
mmol/liter | 0.82 | 1.06 | n.a. | 0.85 | 0.60 | 0.56 | |
Median absolute relative error (%) | 13.3 | 18.4 | 13.0 | 11.8 | 10.7 | 7.7 | |
% readings within ISO 15197 requirementse | 73.2 | 52.2 | 74.0 | 72.2 | 76.9 | 89.3 | |
Point Accuracy – Hypoglycemia, BG ≥ 70 mg/dl [3.9 mmol/liter]f | |||||||
Mean absolute error | mg/dl | 9.9 | 13.1 | n.a. | 6.5 | 8.5 | 7.4 |
mmol/liter | 0.55 | 0.73 | n.a. | 0.36 | 0.47 | 0.41 | |
Mean absolute relative error (%) | 16.1 | 21.5 | 25.0 | 10.3 | 17.5 | 14.2 | |
Median absolute rrror | mg/dl | 7.6 | 11.52 | n.a. | 4.3 | 7.2 | 5.9 |
mmol/liter | 0.42 | 0.64 | n.a. | 0.24 | 0.40 | 0.33 | |
Median absolute relative error (%) | 13.8 | 22.5 | 20.0 | 7.4 | 15.6 | 9.6 | |
% readings within ISO 15197 requirementse | 76.5 | 52.9 | n.a. | 79.4 | 83.0 | 80.0 | |
Rate accuracy – Descent into hypoglycemia | |||||||
Absolute rate deviation | mg/dl/min | 0.87 | 0.72 | n.a. | 0.66 | 1.74 | 0.75 |
mmol/liter/h | 2.9 | 2.4 | n.a. | 2.2 | 5.8 | 2.5 | |
Rate accuracy – Ascent from hypoglycemia | |||||||
Absolute rate deviation | mg/dl/min | 0.90 | 0.99 | n.a. | 0.99 | 2.79 | 0.45 |
mmol/liter/h | 3.0 | 3.3 | n.a. | 3.3 | 9.3 | 1.5 |
DexCom SEVEN PLUS system assumes the euglycemic range to be 80–180 mg/dl (4.4–10.0 mmol/liter).30
Data from Kovatchev BP, Anderson S, Heinemann L, Clarke WL. Comparison of the numerical and clinical accuracy of four continuous glucose monitors. Diabetes Care. 2008;31:1160–4.20
Data from: SEVEN PLUS User Guide. Dexcom, Inc: San Diego, CA.30
n.a., data not available
Overall percentage of readings falling within ±15 mg/dl (if <75 mg/dl) and ±20% (if ≥75 mg/dl) of the reference values, according to the ISO 15197 accuracy requirements (bias plot).23 ISO, International Organization for Standardization.
DexCom SEVEN plus system defines as hypoglycemia BG levels ≥80 mg/dl (≥4.4 mmo/liter).30