Table 3.
Quality parameter of the different models (n = 1,760, development data set)
| Model | P | A | P+A | B1 | P+A+B1 | B2 | P+A+B1+B2 | TRISS | RISC |
|---|---|---|---|---|---|---|---|---|---|
| Quality criteria | |||||||||
| Discrimination | |||||||||
| Prognosis survivors (S) | 12.5 | 11.1 | 10.3 | 10.3 | 9.2 | 9.6 | 8 | 13.4 | 10 |
| Prognosis non-survivors | 16.8 | 25.9 | 31.2 | 31.2 | 38.7 | 33.8 | 46.9 | 49 | 48.8 |
| (N-S) | |||||||||
| Difference between S | 4.3 | 14.8 | 20.9 | 20.9 | 29.5 | 24.2 | 38.9 | 35.6 | 38.8 |
| and n-S | |||||||||
| Sensitivity | 0 | 13.0 | 23.5 | 25.2 | 34.3 | 18.3 | 40.9 | 47.4 | 43.5 |
| Specificity | 100 | 98.4 | 97.8 | 98.9 | 98.1 | 98.3 | 98.2 | 91.6 | 96.2 |
| Overall accuracy | 86.9 | 90.0 | 88.1 | 89.3 | 89.8 | 87.8 | 90.7 | 86.0 | 89.3 |
| Nagelkerkes R2 [24] | 0.07 | 0.21 | 0.29 | 0.27 | 0.38 | 0.34 | 0.49 | n.a. | n.a. |
| AUC of ROC | 0.63 | 0.76 | 0.82 | 0.78 | 0.85 | 0.84 | 0.90 | 0.85 | 0.90 |
| 95% CI | 0.59-0.67 | 0.72-0.79 | 0.79-0.85 | 0.75-0.82 | 0.82-0.88 | 0.81-0.87 | 0.88-0.92 | 0.82-0.88 | 0.89-0.92 |
| Precision | |||||||||
| Observed mortality (%) | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 |
| Score prognosis (%) | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 | 18.0 | 15.1 |
| Calibration | |||||||||
| H-l [25] | n.a. | 1.34 | 5.29 | 2.36 | 4.19 | 4.66 | 11.48 | 136.10 | 17.30 |
| p-value | n.a. | 0.511 | 0.259 | 0.500 | 0.522 | 0.701 | 0.120 | < 0.001 | 0.027 |
P Patients basic data; A Prehospital phase; B1 early trauma room phase; B2 late trauma room phase; TRISS trauma and injury severity score, RISC revised injury severity classification score; S survivors; N-S non-survivors; AUC area under the curve. Roc receiver operating characteristic; CI confidence interval; H-L Goodness of fit statistics according to Hosmer and Lemeshow [25]; n.a. not applicable