Table 3.
Global importance of the top 20 most important predictors for the logistic Regression (LR) and random forest (RF) model, ranked based on mean SHAP magnitude.
| Predictor | Predictor importance LR model (mean |SHAP|, log-odds scale) | Predictor | Predictor importance RF model (mean |SHAP|, probability scale) |
|---|---|---|---|
| Age [y] | 0.453 | pH (arterial) | 0.0044 |
| pH (arterial) | 0.333 | SpO2/FiO2 | 0.0037 |
| FiO2 [%] | 0.332 | FiO2 [%] | 0.0034 |
| Sodium [mmol/L] | 0.257 | PaO2/FiO2 [mmHg] | 0.0026 |
| Haemoglobin [mmol/L] | 0.211 | SpO2 [%] | 0.0017 |
| SpO2 [%] | 0.207 | Potassium [mmol/L] | 0.0016 |
| Heart rate [bpm] | 0.181 | Age [y] | 0.0014 |
| Chloride [mmol/L] | 0.175 | SBP [mmHg] | 0.0013 |
| Potassium [mmol/L] | 0.160 | Base excess [mmol/L] | 0.0011 |
| PaO2 (arterial) [mmHg] | 0.131 | PaCO2 (arterial) [mmHg] | 0.0010 |
| SBP [mmHg] | 0.130 | White cell count [109/L] | 0.0008 |
| PaCO2 (arterial) [mmHg] | 0.116 | ICU length of stay [hours] | 0.0008 |
| Platelet Count [109/L] | 0.116 | Creatinine [μmol/L] | 0.0006 |
| White cell count [109/L] | 0.114 | Heart rate [bpm] | 0.0006 |
| ICU length of stay [hours] | 0.112 | PaO2 (arterial) [mmHg] | 0.0006 |
| SpO2/FiO2 | 0.111 | ASAT [U/L] | 0.0006 |
| Urea Creatinine ratio | 0.092 | Urea [mmol/L] | 0.0006 |
| Ionised calcium [mmol/L] | 0.078 | Haemoglobin [mmol/L] | 0.0005 |
| Haematocrit | 0.069 | Ionised calcium [mmol/L] | 0.0005 |
| Respiratory rate [/min] | 0.068 | Respiratory rate [/min] | 0.0005 |