Table 3.
Test characteristics of prediction models for outcomes on test cohort
| Outcome | Model | Specificity (95% CI) | Sensitivity (95% CI) | PPV (95% CI) | NPV (95% CI) | Cut-off |
| TBI | ||||||
| LR | 47.5 (40.9 to 54.0) | 80.3 (68.7 to 89.1) | 29.9 (23.3 to 37.3) | 89.6 (82.9 to 94.3) | 0.136 | |
| XGB | 72.5 (66.3 to 78.1) | 80.3 (68.7 to 89.1) | 44.9 (35.7 to 54.3) | 92.9 (88.2 to 96.2) | 0.268 | |
| SVM | 64.8 (58.4 to 70.9) | 80.3 (68.7 to 89.1) | 39.0 (30.7 to 47.7) | 92.2 (87.0 to 95.8) | 0.191 | |
| RF | 68.2 (61.9 to 74.1) | 80.3 (68.7 to 89.1) | 41.4 (32.8 to 50.4) | 92.5 (87.6 to 96.0) | 0.185 | |
| EN | 61.0 (54.5 to 67.3) | 80.3 (68.7 to 89.1) | 36.6 (28.7 to 44.9) | 91.7 (86.3 to 95.5) | 0.205 | |
| TBI-I | ||||||
| LR | 71.1 (65.0 to 76.7) | 80.4 (67.6 to 89.8) | 38.8 (29.9 to 48.3) | 94.1 (89.7 to 97.0) | 0.164 | |
| XGB | 74.0 (68.0 to 79.4) | 80.4 (67.6 to 89.8) | 41.3 (31.9 to 51.1) | 94.3 (90.0 to 97.1) | 0.143 | |
| SVM | 71.1 (65.0 to 76.7) | 80.4 (67.6 to 89.8) | 38.8 (29.9 to 48.3) | 94.1 (89.7 to 97.0) | 0.172 | |
| RF | 76.0 (70.2 to 81.2) | 80.4 (67.6 to 89.8) | 43.3 (33.6 to 53.3) | 94.4 (90.3 to 97.2) | 0.205 | |
| EN | 81.3 (75.9 to 86.0) | 80.4 (67.6 to 89.8) | 49.5 (38.8 to 60.1) | 94.8 (90.9 to 97.4) | 0.204 | |
| TBI-ND | ||||||
| LR | 46.1 (39.8 to 52.6) | 80.7 (68.1 to 90.0) | 25.8 (19.6 to 32.9) | 91.1 (84.7 to 95.5) | 0.090 | |
| XGB | 66.5 (60.2 to 72.4) | 80.7 (68.1 to 90.0) | 35.9 (27.7 to 44.9) | 93.7 (89.0 to 96.8) | 0.242 | |
| SVM | 59.2 (52.7 to 65.4) | 80.7 (68.1 to 90.0) | 31.5 (24.1 to 39.7) | 92.9 (87.7 to 96.4) | 0.147 | |
| RF | 60.4 (54.0 to 66.6) | 80.7 (68.1 to 90.0) | 32.2 (24.6 to 40.5) | 93.1 (88.0 to 96.5) | 0.138 | |
| EN | 74.3 (68.3 to 79.6) | 80.7 (68.1 to 90.0) | 42.2 (32.8 to 52.0) | 94.3 (90.0 to 97.1) | 0.201 | |
| TBI-D | ||||||
| LR | 42.6 (36.9 to 48.5) | 81.8 (48.2 to 97.7) | 5.1 (2.4 to 9.5) | 98.4 (94.4 to 99.8) | 0.005 | |
| XGB | 57.7 (51.8 to 63.5) | 81.8 (48.2 to 97.7) | 6.8 (3.2 to 12.5) | 98.8 (95.8 to 99.9) | 0.002 | |
| SVM | 74.2 (68.8 to 79.2) | 81.8 (48.2 to 97.7) | 10.7 (5.0 to 19.4) | 99.1 (96.7 to 99.9) | 0.039 | |
| RF | 74.9 (69.5 to 79.8) | 81.8 (48.2 to 97.7) | 11.0 (5.1 to 19.8) | 99.1 (96.8 to 99.9) | 0.005 | |
| EN | 79.0 (73.9 to 83.6) | 81.8 (48.2 to 97.7) | 12.9 (6.1 to 23.0) | 99.1 (96.9 to 99.9) | 0.033 |
EN, elastic net; LR, logistic regression analysis; RF, random forest; SVM, support vector machine; TBI, traumatic brain injury; TBI-D, traumatic brain injury with death; TBI-I, traumatic brain injury with intracranial injury; TBI-ND, traumatic brain injury with non-discharge; XGB, extreme gradient boosting.