Discrimination performance of laboratory test for the prediction of hospital mortality in logistic regression models with and without healthcare process variables
| Variables | AUC for model 1 (95% CI) | AUC for model 2 (95% CI) | P value* |
| PaO2 | 0.664 (0.634 to 0.694) | 0.639 (0.609 to 0.670) | 0.001 |
| Hematocrit | 0.605 (0.573 to 0.636) | 0.583 (0.554 to 0.613) | 0.147 |
| Potassium | 0.612 (0.580 to 0.644) | 0.600 (0.570 to 0.631) | 0.356 |
| Albumin | 0.594 (0.567 to 0.622) | 0.590 (0.563 to 0.618) | 0.333 |
| Glucose | 0.630 (0.601 to 0.660) | 0.555 (0.534 to 0.575) | <0.001 |
| Bilirubin | 0.611 (0.581 to 0.640) | 0.603 (0.574 to 0.632) | 0.022 |
| Bicarbonate | 0.692 (0.661 to 0.723) | 0.664 (0.635 to 0.694) | 0.001 |
| WBC | 0.634 (0.603 to 0.666) | 0.610 (0.580 to 0.641) | 0.015 |
| BUN | 0.681 (0.650 to 0.712) | 0.665 (0.635 to 0.695) | 0.025 |
| pH | 0.665 (0.635 to 0.695) | 0.636 (0.605 to 0.666) | 0.001 |
| Sodium | 0.615 (0.583 to 0.647) | 0.587 (0.558 to 0.616) | 0.043 |
| Creatinine | 0.671 (0.640 to 0.701) | 0.620 (0.590 to 0.650) | <0.001 |
*The AUCs of two ROC curves were compared using DeLong method, and p values for the comparisons were reported.
Model 2 included only the pathophysiology value; model 1 included healthcare process variables (number of test for the first 24 hours, clock time of the test and the measurement time relative to ICU admission) and the pathophysiology value of corresponding test.
AUC, area under curve; BUN, blood urea nitrogen; ROC, receiver operating characteristic; WBC, white cell count.