Ability of HbA1c, FPG and RPG to define suboptimal glucose control using CGM thresholds <8 and <10 mmol/L
| CGM cut-off | Test | N | AUROC (95% CI) | Optimal threshold | Sensitivity (95% CI) | Specificity (95% CI) | Correctly classified | PPV (95% CI) | NPV (95% CI) |
| ≥8.0 | HbA1c | 191 | 0.95 (0.92 to 0.98) | ≥62 mmol/mol | 90.2 (83.1 to 95.0) | 83.5 (73.5 to 90.9) | 87.4 | 88.6 (81.3 to 93.8) | 85.7 (75.9 to 92.6) |
| FPG | 191 | 0.90 (0.86 to 0.95) | ≥7.6 mmol/l | 84.8 (76.8 to 90.9) | 81.0 (70.6 to 89.0) | 83.3 | 86.4 (78.5 to 92.2) | 79.0 (68.5 to 87.3) | |
| RPG | 192 | 0.82 (0.77 to 0.88) | ≥11.6 mmol/l | 78.6 (69.8 to 85.8) | 64.6 (53.0 to 75.0) | 72.8 | 75.9 (67.0 to 83.3) | 68.0 (56.2 to 78.3) | |
| ≥10.0 | HbA1c | 191 | 0.94 (0.90 to 0.97) | ≥72 mmol/mol | 88.9 (79.3 to 95.1) | 84.9 (77.2 to 90.8) | 86.4 | 78.0 (67.5 to 86.4) | 92.7 (86.0 to 96.8) |
| FPG | 191 | 0.90 (0.85 to 0.95) | ≥9.1 mmol/l | 83.6 (73.0 to 91.2) | 83.1 (75.0 to 89.3) | 83.3 | 75.3 (64.5 to 84.2) | 89.1 (81.7 to 94.2) | |
| RPG | 192 | 0.85 (0.79 to 0.91) | ≥13.8 mmol/l | 84.7 (74.3 to 92.1) | 72.3 (63.3 to 80.1) | 77.0 | 64.9 (54.4 to 74.5) | 88.7 (80.6 to 94.2) |
The units used are as follows: HbA1c—mmol/mol and mmol/L for fasting and random non-fasting glucose.
AUROC, area under receiver operating characteristic curve; CGM, continuous glucose monitoring; FPG, fasting plasma glucose; HbA1c, glycosylated hemoglobin; NPV, negative predictive value; PPV, positive predictive value; RPG, random non-fasting plasma glucose.