TABLE 3.
| Variable | Relative Risk |
95% CI |
|---|---|---|
| ICPM | ||
| Age | ||
| <1 y (referent) | 1 | — |
| 1 to <5 y | 1.63 | (1.29-2.06) |
| 5 to <13 y | 1.53 | (1.20-1.95) |
| 13 to <18 y | 1.55 | (1.23-1.96) |
| Head AIS | ||
| 3 (referent) | 1 | — |
| 5 or 6 | 1.11 | (1.01-1.41) |
| Hospital trauma designation | ||
| Adult I or II (referent) | 1 | — |
| Adult and Peds I or II | 0.80 | (0.66-0.97) |
| Discharge year | ||
| 2002 (referent) | 1 | — |
| 2005 | 0.65 | (0.45-0.93) |
| Other injury features | ||
| Injury Severity Score >15 | 1.36 | (1.14-1.63) |
| Intracranial hemorrhage (EDH, SDH, SAH) | 1.57 | (1.40-1.77) |
| CRANI | ||
| Age | ||
| <1 y (referent) | 1 | — |
| 1 to <5 y | 1.39 | (.01-1.90) |
| Head AIS | ||
| 3 (referent) | 1 | — |
| 4 | 1.33 | (1.06-1.67) |
| Annual TBI case volume | ||
| 10-13 cases (referent) | 1 | — |
| 14-19 cases | 0.74 | (0.58-0.93) |
| Hospital trauma designation | ||
| Adult I or II (referent) | 1 | — |
| Level III/IV/nontrauma center | 1.56 | (1.02-2.38) |
| Other injury features | ||
| Intracranial hemorrhage (EDH, SDH, SAH) | 3.32 | (2.66-4.16) |
ICP, intracranial pressure; RR, relative risk; CI, confidence interval; CRANI, craniotomy/craniectomy; EDH, epidural hematoma; SDH, subdural hematoma; SAH, subarachnoid hematoma; AIS, Abbreviated Injury Score; NTC, nontrauma center; TBI, traumatic brain injury.
Included model covariates included age category, head AIS, sex, severe ISS, inflicted injury, presence of intracranial hemorrhage, insurance status, year of discharge, trauma designation, hospital region, and volume of TBI cases at the patient’s hospital during that year. Only relative risk estimates with confidence intervals excluding 1 are considered significant and are displayed. In cases where nominal variables showed significant results, the referent category is listed for clarity of interpretation.