Article Figures & Data
Figures
- Figure 1
Flow chart of the study population. EMS, emergency medical services; GEMS, ground emergency medical services; HEMS, helicopter emergency medical services; MTC, major trauma center; PS, propensity score; TARN, Trauma Audit and Research Network.
- Figure 2
Standardized difference before and after propensity matching. GCS, Glasgow Coma Scale; MOI, mechanism of injury; O2sat, oxygen saturation; SBP, systolic blood pressure.
Tables
- Table 1
Characteristics of the directly admitted adult population (MTCs only) by mode of arrival: January 2012–March 2017
Mode of arrival Unknown final outcome GEMS HEMS Total Total 54 185 7548 61 733 5748 Male, n (%) 31 487 (58.1) 5619 (74.4) 37 106 (60.1) 3891 (67.7) Age, median (IQR) 61.9 (40.7–80.9) 45.5 (29–60.3) 59.3 (38.5–79.4) 53 (34.5–71.6) Prehospital GCS, median (IQR)* 15 (14–15) 15 (10–15) 15 (14–15) 15 (11–15) Prehospital SBP, median (IQR)* 137 (120–155) 129 (110–146) 136 (119–154) 132 (114–152) ISS 10 (9–20) 20 (10–29) 10 (9–21) 21 (10–29) Prehospital O2sat, median (IQR)* 97 (95–99) 98 (95–100) 97 (95–99) 97 (95–99) Prehospital pulse rate, median (IQR)* 84 (72–98) 88 (72–104) 84 (72–99) 86 (73–102) Prehospital resp rate, median (IQR)* 18 (16–20) 20 (16–24) 18 (16–22) 18 (16–22) Time from leaving scene to arrival to hospital (mins), median (IQR) 24 (17–34) 22 (16–30) 24 (17–34) 25 (17–36) Penetrating injury, n (%) 2459 (4.5) 363 (4.8) 2822 (4.6) 162 (2.8) MOI, n (%) Vehicle incident/collision 13 584 (25.1) 4560 (60.4) 18 144 (29.4) 2494 (43.4) Fall from heights 8527 (15.7) 1387 (18.4) 9914 (16.1) 1368 (23.8) Low fall 26 303 (48.5) 644 (8.5) 26 947 (43.7) 1286 (22.4) Stabbing/shooting 2195 (4.1) 294 (3.9) 2489 (4) 130 (2.3) Other 3576 (6.6) 663 (8.8) 4239 (6.9) 470 (8.2) Prehospital intubation, n (%) 1106 (2) 2115 (28) 3221 (5.2) 744 (12.9) LOS in days, median (IQR) 10 (5–19) 10 (5–20) 10 (5–19) 12 (4–24) Neuro center on site, n (%)† 49 153 (90.7) 7357 (97.5) 56 510 (91.5) 4528 (78.8) Head injury AIS 3+, n (%) 14 481 (26.7) 2703 (35.8) 17 184 (27.8) 2487 (43.3) Attendance at scene, n (%) Consultant 0 (0) 476 (6.3) 476 (0.8) 115 (2) Doctor 0 (0) 3438 (45.5) 3438 (5.6) 749 (13) Paramedic only 48 962 (90.4) 2834 (37.5) 51 796 (83.9) 4232 (73.6) Mortality 4559 (8.4) 1181 (15.6) 5740 (9.3) N/A *Prehospital characteristics are taken from the earliest recorded data.
†Neurosurgery/neurological care facility.
AIS, Abbreviated Injury Scale; GCS, Glasgow Coma Scale; GEMS, ground emergency medical services; HEMS, helicopter emergency medical services; ISS, Injury Severity Score; LOS, length of stay; MOI, mechanism of injury; MTCs, major trauma centers; O2sat, oxygen saturation; SBP, systolic blood pressure.
- Table 2
Missing data
Missing Observed % missing Prehospital GCS 3696 58 037 6.0 SBP 6472 55 261 10.5 Resp rate 6444 55 289 10.4 Pulse rate 4752 56 981 7.7 Oxygen saturation 7670 54 063 12.4 Emergency department GCS 5074 56 659 8.2 SBP 2902 58 831 4.7 Resp rate 7818 53 915 12.7 Pulse rate 2531 59 202 4.1 Oxygen saturation 4042 57 691 6.5 GCS, Glasgow Coma Scale; SBP, systolic blood pressure.
- Table 3
Characteristics of the propensity score matched directly admitted adult population (MTCs only) by mode of arrival: January 2012–March 2017
Total Mode of arrival GEMS HEMS Total P value 4636 4636 9272 Male, n (%) 3442 (74.3) 3350 (72.3) 6792 (73.37) 0.031 Age, median (IQR) 47.2 (30–62.8) 46.8 (30.7–62.7) 47.2 (29.6–62.8) 0.516 Prehospital GCS, median (IQR) 15 (14–15) 15 (15–15) 15 (14–15) 0.999 Prehospital SBP, median (IQR) 130 (115–147) 130 (113–148) 130 (114–147) 0.999 ISS 16 (9–25) 17 (9–26) 16 (9–25) 0.0001 Prehospital O2sat, median (IQR) 97 (95–99) 98 (96–100) 97 (95–99) 0.0001 Prehospital pulse rate, median (IQR) 86 (73–101) 85 (72–100) 85 (72–100) 0.004 Prehospital resp rate, median (IQR) 18 (16–22) 19 (16–24) 18 (16–23) 0.073 Time to arrival to hospital (min), median (IQR) 23 (15–33) 23 (16–31) 25 (15–33) 0.999 Penetrating injury, n (%) 273 (5.9) 261 (5.6) 534 (5.8) 0.593 MOI, n (%) Vehicle incident/collision 2396 (51.7) 2410 (52.0) 4806 (51.8) 0.006 Fall from heights 1034 (22.3) 963 (20.8) 1997 (21.5) Low fall 487 (10.5) 592 (12.8) 1079 (11.6) Stabbing/shooting 244 (5.3) 226 (4.9) 470 (5.1) Other 475 (10.3) 445 (9.6) 920 (9.9) Prehospital intubation, n (%) 232 (5.0) 1043 (22.5) 1275 (13.8) <0.0001 LOS in days, median (IQR) 9 (5–18) 9 (5–18) 9 (5–18) 0.999 Neuro center on site, n (%) 4471 (96.4) 4475 (96.5) 8946 (96.5) 0.822 Head injury AIS 3+, n (%) 1465 (31.6) 1452 (31.3) 2917 (31.5) 0.771 Attendance at scene, n (%) Consultant, n (%) 0 282 (6.1) 22 (3.0) <0.0001 Doctor, n (%) 0 2068 (44.6) 2068 (22.3) Paramedic only, n (%) 4104 (88.5) 1813 (39.1) 5917 (63.8) Mortality, n (%) 448 (9.7) 619 (13.4) 1067 (11.5) <0.0001 GCS, Glasgow Coma Scale; GEMS, ground emergency medical services; HEMS, helicopter emergency medical services; ISS, Injury Severity Score; MOI, mechanism of injury; MTCs, major trauma centers; SBP, systolic blood pressure.
- Table 4
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.
