Table 3.
Mean Absolute Relative Difference (MARD) of Dexcom G4 based on Capillary Versus Venous Glucose References When Calibrating CGM by Capillary Values.
| Capillary | Venous | Venous-capillary | Point estimate (95% CI) for differencea | P value | |
|---|---|---|---|---|---|
| MARD (%) | 11.69 (6.80) 9.81 (0.00; 30.37) n = 41 |
13.66 (6.70) 11.66 (5.72; 34.53) n = 41 |
1.97 (7.74) 2.41 (–22.47; 21.51) n = 41 |
2.03 (0.19; 4.08) | .0371 |
| Pearson correlation | 0.84 (0.25) 0.93 (–0.20; 1.00) n = 38 |
0.85 (0.20) 0.93 (0.07; 1.00) n = 38 |
0.01 (0.15) −0.00 (–0.34; 0.62) n = 38 |
−0.00 (–0.03; 0.02) | .7489 |
| MARD (%) hypoglycemic range: venous glucose <72 mg/dL (<4 mmol/L) | 16.58 (15.38) 11.43 (0.00; 52.94) n = 13 |
31.81 (25.96) 25.81 (3.23; 88.73) n = 13 |
15.24 (31.52) 14.14 (–49.72; 82.48) n = 13 |
14.14 (0.41; 32.99) | .0479 |
| MARD (%) euglycemic range: venous glucose 72-180 mg/dL (4-10 mmol/L) | 12.09 (7.98) 9.32 (0.00; 40.00) n = 38 |
12.56 (6.30) 11.92 (2.44; 26.84) n = 38 |
0.47 (9.92) 1.63 (–37.56; 19.49) n = 38 |
1.19 (–1.63; 3.99) | .3199 |
| MARD (%) hyperglycemic range: venous glucose >180 mg/dL (>10 mmol/L) | 8.74 (6.57) 7.37 (0.77; 23.32) n = 24 |
9.16 (5.83) 9.07 (0.00; 27.20) n = 24 |
0.42 (7.43) 0.60 (–14.23; 15.23) n = 24 |
0.43 (–3.06; 3.40) | .8247 |
Data are mean (SD) / median / (min; max) / n. Point estimates and confidence intervals for differences were obtained using Hodges–Lehmann’s procedure. For comparison of accuracy, the Wilcoxon signed-rank test was used.
a
Venous-capillary.