Odds of death for HEMS versus GEMS transport to hospital for major trauma
| Criteria | OR of death | 95% CI | P value |
| Entire matched cohort (9272) | 0.846 | 0.684 to 1.046 | 0.122 |
| Prehospital GCS ≤8 | |||
| Present (1417) | 0.733 | 0.508 to 1.059 | 0.098 |
| Absent (7855) | 1.150 | 0.862 to 1.534 | 0.340 |
| Prehospital respiratory rate <10 or >29 | |||
| Present (1007) | 0.760 | 0.498 to 1.161 | 0.204 |
| Absent (8265) | 0.894 | 0.692 to 1.156 | 0.393 |
| Prehospital hemorrhagic shock (SBP <90) | |||
| Present (596) | 0.330 | 0.078 to 1.391 | 0.165 |
| Absent (8676) | 0.944 | 0.753 to 1.183 | 0.615 |
GCS, Glasgow Coma Scale; GEMS, ground emergency medical services; HEMS, helicopter emergency medical services; SBP, systolic blood pressure.