Table 1.
Performance Evaluation Metrics
| GMS1A | GMS1B | GMS2A | GMS2B | GMS3 | GMS4 | |
|---|---|---|---|---|---|---|
| n | 613 | 613 | 613 | 613 | 613 | 613 |
| Clarke Error Grid, % | ||||||
| Zone A | 94.9 | 95.3 | 93.6 | 94.8 | 91.5 | 80.3 |
| Zone B | 4.7 | 4.6 | 5.5 | 4.6 | 8.0 | 17.3 |
| Zone D | 0.3 | 0.2 | 0.8 | 0.7 | 0.5 | 2.4 |
| Modified Bland-Altman Analysis | ||||||
| Bias, mg/dl, mean ± SD | -3.38 ± 12.49 | -2.74 ± 12.12 | -1.97 ± 13.21 | -1.29 ± 12.73 | 4.40 ± 14.70 | 2.66 ± 19.41 |
| 95% CI | (-4.37,-2.39) | (-3.70,-1.78) | (-3.02,-0.92) | (-2.30,-0.28) | (3.24,5.57) | (1.12,4.20) |
| ISO 15197 Guideline, % | ||||||
| <75 mg/dl | 87.5 | 90.6 | 86.5 | 86.5 | 80.2 | 62.5 |
| ≥75 mg/dl | 94.8 | 95.0 | 94.6 | 95.7 | 91.9 | 82.4 |
| Linear Regression | ||||||
| r2 | 0.95 | 0.95 | 0.94 | 0.94 | 0.94 | 0.87 |
| y-intercept (95% CI) | -1.87 (-4.37-0.63) | 0.76 (-1.65-3.17) | 6.20 (3.65-8.74) | 6.24 (3.78-8.70) | -6.02 (-8.82-(-3.21)) | 8.92 (5.08-12.77) |
| Slope (95%CI) | 0.99 (0.97-1.01) | 0.97 (0.95-0.99) | 0.93 (0.91-0.95) | 0.94 (0.92-0.96) | 1.09 (1.06-1.11) | 0.95 (0.92-0.98) |
| Absolute Difference (AD), mg/dl, mean ± SD | ||||||
| All Measurements | 9.1 ± 9.2 | 8.5 ± 9.1 | 9.8 ± 9.1 | 9.3 ± 8.7 | 11.5 ± 10.2 | 14.6 ± 13.0 |
| <70 mg/dl | 7.9 ± 6.6 | 6.8 ± 5.3 | 7.4 ± 6.3 | 6.4 ± 6.3 | 9.3 ± 7.0 | 10.6 ± 8.6 |
| 70 – 110 mg/dl | 6.7 ± 6.4 | 6.1 ± 6.4 | 8.1 ± 6.9 | 7.8 ± 6.2 | 9.9 ± 8.4 | 11.8 ± 9.1 |
| 111 - 150 mg/dl | 8.5 ± 8.0 | 8.4 ± 7.5 | 10.5 ± 9.6 | 9.7 ± 8.1 | 11.2 ± 9.8 | 14.3 ± 11.7 |
| 151 - 180 mg/dl | 14.3 ± 12.0 | 9.5 ± 10.4 | 10.6 ± 8.9 | 12.3 ± 11.0 | 13.0 ± 11.9 | 21.7 ± 20.0 |
| >180 mg/dl | 15.1 ± 13.6 | 16.1 ± 14.9 | 14.5 ± 12.9 | 13.5 ± 13.4 | 17.6 ± 14.1 | 22.1 ± 17.6 |
| Relative Absolute Difference (RAD), %, mean ± SD | ||||||
| All Measurements | 8.4 ± 11.6 | 7.7 ± 11.7 | 9.2 ± 13.8 | 8.6 ± 12.9 | 10.5 ± 11.4 | 13.3 ± 16.0 |
| <70 mg/dl | 18.1 ± 27.3 | 16.0 ± 28.6 | 17.9 ± 34.5 | 15.4 ± 33.1 | 19.4 ± 23.2 | 23.4 ± 37.5 |
| 70 – 110 mg/dl | 7.3 ± 7.2 | 6.6 ± 6.8 | 9.0 ± 8.2 | 8.7 ± 7.1 | 10.9 ± 9.5 | 13.1 ± 10.2 |
| 111 - 150 mg/dl | 6.5 ± 6.0 | 6.5 ± 5.5 | 8.0 ± 7.1 | 7.4 ± 5.8 | 8.7 ± 7.4 | 11.0 ± 9.0 |
| 151 - 180 mg/dl | 8.7 ± 7.2 | 5.7 ± 6.0 | 6.5 ± 5.5 | 7.4 ± 6.6 | 8.0 ± 7.2 | 13.2 ± 12.0 |
| >180 mg/dl | 7.0 ± 6.3 | 7.3 ± 6.8 | 6.3 ± 5.4 | 5.9 ± 5.5 | 7.7 ± 5.8 | 10.0 ± 8.0 |
| Bracket Predictive Value (80 – 110 mg/dl), % | ||||||
| Positive BPV | 83.5 | 80.5 | 78.5 | 77.7 | 82.6 | 67.0 |
| Negative BPV | 93.5 | 95.2 | 91.2 | 90.0 | 88.6 | 86.5 |
Note: Glucose, mg/dl × 0.0555 = glucose, mmol/L.