Table 3.
Comparison of model performance based on sensitivity, specificity, and false alerts with patient-based and time-based validation for 30-minute and 60-minute prediction horizons (PHs).
| Metrics | Patient-based validation | Time-based validation | |||||||||||||||
|
|
30-minute PH | 60-minute PH | 30-minute PH | 60-minute PH | |||||||||||||
|
|
Method 1: RFa | Method 2: QRFb | Method 1: RF | Method 2: QRF | Method 1: RF | Method 2: QRF | Method 1: RF | Method 2: QRF | |||||||||
| Sensitivity, % (SD) | 39.11 (2.25) | 99.09 (0.16) | 49.27 (3.03) | 97.61 (0.41) | 96.17 | 98.94 | 95.34 | 97.91 | |||||||||
| Specificity, % (SD) | 98.65 (0.09) | 98.19 (0.10) | 98.63 (0.12) | 98.09 (0.11) | 98.3 | 98.29 | 97.95 | 98.20 | |||||||||
| False alerts, n (SD) |
|
|
|
|
|
|
|
|
|||||||||
|
|
Considering transient and nonhypoglycemic events as false | 6936 (356) | 9339 (459) | 7043 (317) | 9672 (431) | 6476 | 8211 | 7346 | 8465 | ||||||||
|
|
Considering only nonhypoglycemic events as false | 3907 (200) | 5368 (162) | 4109 (156) | 5677 (201) | 3324 | 4531 | 4334 | 4799 | ||||||||
| False alert rate, % (SD) | 26.32 (2.56) | 26.50 (2.41) | 26.44 (2.37) | 26.36 (2.57) | 22.79 | 23.86 | 26.41 | 23.79 | |||||||||
aRF: random forest.
bQRF: quantile regression forest.