Table 5.
Descriptive characteristics by the true positive (n=97), false negative (n=41; missed MH), false positive (n=45; MH overdiagnosis) and true negative (n=764) decisions to activate the major hemorrhage protocol prehospital
| Variable | Missing | MHPA TP | MHPA FN | MHPA FP | MHPA TN | P values | |||
| N (%) | N (%) or median (IQR) | N (%) or median (IQR) | N (%) or median (IQR) | N (%) or median (IQR) | TP vs FN | FN vs rest (TP+FP+ TN) | Trend | ||
| Patient | Age | 26 (3%) | 29 (20.5 to 40.5) | 27 (20.5 to 47) | 27 (20 to 44) | 33 (24 to 48) | 0.7163* | 0.1719* | 0.2131† |
| Female sex | 26 (3%) | 12 (12%) | 8 (20%) | 11 (24%) | 90 (12%) | 0.30‡ | 0.23‡ | 0.07§ | |
| Penetrating mechanism | 26 (3%) | 50 (52%) | 25 (61%) | 24 (53%) | 269 (36%) | 0.35‡ | 0.008‡ | <0.001§ | |
| ISS | 27 (3%) | 24.5 (16 to 34) | 19 (11.5 to 33.5) | 15 (8.2 to 21.5) | 10 (1.8 to 19) | 0.3019* | <0.0001* | <0.0001† | |
| GCS | 7 (1%) | 11 (3.5 to 14) | 15 (9.5 to 15) | 14 (13 to 15) | 15 (12 to 15) | 0.0001* | 0.4220* | <0.0001† | |
| SBP | 19 (2%) | 86 (54 to 107) | 119 (96.5 to 133) | 103 (75 to 122) | 131 (117 to 146) | <0.0001* | 0.0327* | <0.0001† | |
| HR | 6 (1%) | 104 (67 to 131) | 95 (75 to 108.5) | 99 (80 to 114) | 92 (79 to 106) | 0.2207* | 0.8437* | 0.0842† | |
| AIS number | 45 (5%) | 3 (1 to 4) | 2 (1 to 4) | 1 (0 to 2) | 1 (0 to 1) | 0.2554* | 0.4460* | 0.0002† | |
| Clinician | Years experience <1 year | 2 (0%) | 70 (72%) | 32 (78%) | 38 (84%) | 598 (78%) | 0.39§ | 0.48§ | 0.58§ |
| 1 to 5 years | – | 19 (20%) | 4 (10%) | 4 (9%) | 114 (15%) | ||||
| 5 to 10 years | – | 3 (3%) | 3 (7%) | 2 (4%) | 29 (4%) | ||||
| >10 years | – | 5 (5%) | 2 (5%) | 1 (2%) | 21 (3%) | ||||
| Base specialty emergency medicine | 2 (0%) | 50 (52%) | 23 (56%) | 26 (58%) | 451 (59%) | 0.89§ | 0.90§ | 0.24§ | |
| Anesthetics | – | 39 (40%) | 15 (37%) | 19 (42%) | 243 (32%) | ||||
| Intensive care | – | 8 (8%) | 3 (7%) | 0 (0%) | 68 (9%) | ||||
| Environment | Nightshift | 0 (0%) | 51 (53%) | 23 (56%) | 26 (58%) | 411 (54%) | >0.71‡ | >0.87‡ | 0.94§ |
| Biochemistry | pH | 432 (46%) | 7.22 (7.05 to 7.29) | 7.28 (7.21 to 7.35) | 7.30 (7.26 to 7.34) | 7.34 (7.30 to 7.38) | 0.0093* | 0.0609* | <0.0001† |
| Lactate | 358 (38%) | 6.6 (4.0 to 10.8) | 4.2 (2.7 to 5.9) | 4.0 (2.5 to 8.8) | 2.6 (1.8 to 4.1) | 0.0006* | 0.0518* | <0.0001† | |
| Base excess | 433 (46%) | −8.8 (−14.1 to 4.1) | −4.5 (−8.9 to −1.3) | −4.7 (−8.5 to −0.4) | −0.9 (−3.5 to 0.9) | 0.0038* | 0.0319* | <0.0001† | |
| INR | 165 (17%) | 1.2 (1.1 to 1.3) | 1.1 (1.1 to 1.2) | 1.1 (1.1 to 1.2) | 1.1 (1.0 to 1.1) | 0.1606* | 0.0029* | <0.0001† | |
| Platelets | 9 (1%) | 187 (144 to 251) | 236 (194 to 277) | 247 (203 to 276) | 243 (205 to 288) | 0.0032* | 0.6161* | <0.0001† | |
| Fibrinogen | 182 (19%) | 2.01 (1.60 to 2.58) | 1.91 (1.62 to 2.43) | 2.22 (1.88 to 2.54) | 2.46 (2.09 to 2.95) | 0.5934* | <0.0001* | <0.0001† | |
| Outcome | Blood products in 24 hours | 0 (0%) | 16 (10 to 27) | 11 (8 to 17) | 2 (0 to 3) | 0 (0 to 0) | 0.0027* | <0.0001* | <0.0001† |
| Prehospital hemorrhage intervention | 0 (0%) | 26 (27%) | 0 (0%) | 0 (0%) | 1 (0.1%) | <0.001‡ | 0.63‡ | <0.001§ | |
| Hemorrhage control surgery | 0 (0%) | 69 (71%) | 21 (51%) | 7 (16%) | 15 (2%) | 0.03‡ | <0.001‡ | <0.001§ | |
| TCA due to hemorrhage | 0 (0%) | 19 (20%) | 2 (5.1%) | 1 (2%) | 1 (0.1%) | 0.04‡ | 0.26‡ | <0.001§ | |
| Mortality due to hemorrhage | 0 (0%) | 30 (31%) | 6 (15%) | 1 (2%) | 4 (0.5%) | 0.06‡ | 0.007‡ | <0.001§ | |
| Mortality all cause | 0 (0%) | 33 (34%) | 7 (17%) | 2 (4%) | 37 (5%) | 0.06‡ | 0.07‡ | <0.001§ | |
*Mann-Whitney U test, two-tailed.
†Kruskall-Wallis test.
‡Fisher’s exact test.
§χ2 test.
AIS, Abbreviated Injury Scale; CAT, critical admission threshold; FN, false negative; FP, false positive; GCS, Glasgow Coma Scale; HR, heart rate; INR, international normalized ratio; ISS, Injury Severity Scale; MHPA, major hemorrhage protocol activation; SBP, systolic blood pressure; TCA, traumatic cardiac arrest; TN, true negative; TP, true positive.