Table 2.
Multi-Variable Logistic Regression Analysis: IMPACT Core Model Plus Cerebrovascular Reactivity
| Model | AUC A/D (95% CI) | AIC | p value | AUC F/U (95% CI) | AIC | p value |
|---|---|---|---|---|---|---|
| CORE | 0.707 (0.611–0.798) | 176.3 | <0.0001 | 0.638 (0.561–0.713) | 236.5 | <0.0001 |
| CORE + mean ICP | 0.780 (0.697–0.855) | 164.9 | <0.0001 | 0.651 (0.574–0.729) | 237.2 | 0.0001 |
| CORE + % time ICP >20 mm Hg | 0.811 (0.734–0.881) | 158.7 | <0.0001 | 0.647 (0.571–0.724) | 235.7 | 0.0001 |
| CORE + % time ICP >22 mm Hg | 0.811 (0.727–0.884) | 160.5 | <0.0001 | 0.648 (0.570–0.725) | 236.3 | 0.0001 |
| % time above PRx thresholds | ||||||
| CORE + % time PRx >0 | 0.781 (0.694–0.865) | 163.3 | <0.0001 | 0.654 (0.575–0.728) | 236.3 | 0.0002 |
| CORE + % time PRx >+0.25 | 0.803 (0.721–0.877) | 157.4 | <0.0001 | 0.661 (0.584–0.758) | 235.5 | 0.0001 |
| CORE + % time PRx >+0.35 | 0.812 (0.727–0.884) | 155.2 | <0.0001 | 0.661 (0.584–0.737) | 235.3 | 0.0001 |
| Mean ICP + % time above PRx thresholds | ||||||
| CORE + mean ICP + % time PRx >0 | 0.807 (0.724–0.883) | 158.7 | <0.0001 | 0.653 (0.575–0.729) | 237.6 | 0.0001 |
| CORE + mean ICP + % time PRx >+0.25 | 0.819 (0.735–0.888) | 155.6 | <0.0001 | 0.659 (0.582–0.731) | 237.1 | 0.0001 |
| CORE + mean ICP + % time PRx >+0.35 | 0.825 (0.747–0.893) | 154.3 | <0.0001 | 0.661 (0.583–0.733) | 237.0 | 0.0001 |
| % time ICP >20 mm Hg + % time above PRx thresholds | ||||||
| CORE + % time ICP >20 mm Hg + % time PRx >0 | 0.812 (0.729–0.883) | 154.9 | <0.0001 | 0.647 (0.570–0.730) | 236.4 | 0.0001 |
| CORE + % time ICP >20 mm Hg + % time PRx >+0.25 | 0.818 (0.744–0.893) | 152.6 | <0.0001 | 0.651 (0.566–0.730) | 236.1 | 0.0001 |
| CORE + % time ICP >20 mm Hg + % time PRx >+0.35 | 0.822 (0.742–0.890) | 151.6 | <0.0001 | 0.649 (0.571–0.721) | 236.1 | 0.0001 |
| % time ICP >22 mm Hg + % time above PRx thresholds | ||||||
| CORE + % time ICP >22 mm Hg + % time PRx >0 | 0.810 (0.726–0.885) | 156.8 | <0.0001 | 0.648 (0.570–0.723) | 237.1 | 0.0001 |
| CORE + % time ICP >22 mm Hg + % time PRx >+0.25 | 0.814 (0.735–0.886) | 154.4 | <0.0001 | 0.647 (0.570–0.720) | 236.7 | 0.0001 |
| CORE + % time ICP >22 mm Hg + % time PRx >+0.35 | 0.817 (0.736–0.889) | 153.3 | <0.0001 | 0.647 (0.570–0.720) | 236.6 | 0.0001 |
CORE model consisted of age, admission Glasgow Coma Scale motor score, and pupil response (normal bilaterally, unilateral unreactive, or bilaterally unreactive).
A/D, alive/dead; AIC, Akaike information criteria; AUC, area under the receiver operating curve; CPP, cerebral perfusion pressure; CI, confidence interval; F/U, favorable/unfavorable outcome (i.e., favorable = Glasgow Outcome Scale of 5–8; unfavorable = Glasgow Outcome Scale of 1–4); ICP, intracranial pressure; IMPACT, International Mission for Prognosis and Analysis of Clinical Trials; MAP, mean arterial pressure; PRx, pressure reactivity index (correlation between ICP and MAP).