Table 1.
Patient Demographics and Injury Characteristics, No. (%) by Theater of Operation (June 2009 – December 2013)
| Characteristic1 | Total (N = 5290) |
Afghanistan (N = 4766) |
Iraq (N = 524) |
||||
|---|---|---|---|---|---|---|---|
|
Noncombat Injury (N=852) |
Combat- related Injury (N=3914) |
p-value2 |
Noncombat Injury (N=239) |
Combat-related Injury (N=285) |
p-value3 | ||
| Male | 5160 (97.5) | 813 (95.4) | 3853 (98.4) | <0.0001 | 223 (93.3) | 271 (95.0) | 0.382 |
| Age, median (IQR) | 24.9 (22.1, 29.6) | 26.4 (22.6, 34.4) | 24.4 (22.0, 28.3) | <0.0001 | 28.1 (22.8, 35.8) | 25.7 (22.6, 30.8) | 0.012 |
| Branch of Service | <0.001 | 0.031 | |||||
| Army | 3608 (68.2) | 552 (64.7) | 2619 (66.9) | 187 (78.2) | 250 (87.7) | ||
| Marine | 1206 (22.7) | 151 (17.7) | 1034 (26.4) | 14 (5.8) | 7 (2.4) | ||
| Military Grade/Rank | 0.003 | 0.462 | |||||
| Enlisted | 4790 (90.5) | 747 (87.6) | 3573 (91.2) | 213 (89.1) | 257 (90.1) | ||
| Officer / Warrant | 379 (7.2) | 80 (9.4) | 256 (6.5) | 22 (9.2) | 21 (7.4) | ||
| Mechanism of Injury | <0.0001 | <0.0001 | |||||
| Blast | 2912 (55.0) | 0 | 2764 (70.6) | <0.0001 | 0 | 148 (51.9) | <0.0001 |
| IED | 2262 (42.8) | 0 | 2163 (55.3) | 0 | 99 (34.7) | ||
| Non-IED | 650 (12.3) | 0 | 601 (15.4) | 0 | 49 (17.2) | ||
| Gunshot wound only | 965 (18.2) | 0 | 918 (23.5) | 0 | 47 (16.5) | ||
| Motor vehicle collision only | 195 (3.7) | 10 (1.2) | 110 (2.8) | 6 (2.5) | 69 (24.2) | ||
| Helicopter crash | 35 (0.7) | 0 | 30 (0.8) | 0 | 5 (1.8) | ||
| Blunt object | 118 (2.2) | 79 (9.3) | 3 (<0.1) | 33 (13.8) | 3 (1.1) | ||
| Fall | 384 (7.3) | 273 (32.0) | 31 (0.8) | 74 (31.0) | 6 (2.1) | ||
| Sports | 180 (3.4) | 130 (15.3) | 0 | 50 (20.9) | 0 | ||
| Other4 | 499 (9.4) | 358 (42.0) | 58 (1.5) | 76 (31.8) | 7 (2.5) | ||
| Dismounted at time of injury | 1708 (32.3) | 283 (33.2) | 1299 (33.2) | <0.0001 | 85 (35.6) | 41 (14.4) | <0.0001 |
| Injury Severity Score, median (IQR) | 10 (5, 22) | 4 (4, 8) | 12 (6, 27) | <0.0001 | 4 (4, 8) | 10 (5, 21) | <0.0001 |
| RBC Transfusions: 1st 24 Hours | <0.0001 | <0.0001 | |||||
| 0/missing units5 | 3927 (74.2) | 838 (98.3) | 2634 (67.2) | 237 (99.1) | 218 (76.4) | ||
| 1–9 units | 761 (14.3) | 11 (1.2) | 698 (17.8) | 2 (0.8) | 50 (17.5) | ||
| 10 – 20 units | 336 (6.3) | 2 (0.2) | 322 (8.2) | 0 | 12 (4.2) | ||
| >20 units | 266 (5.0) | 1 (0.1) | 260 (6.6) | 0 | 5 (1.7) | ||
| Occurrence of open injury | 3793 (71.7) | 233 (27.3) | 3281 (83.8) | <0.0001 | 61 (25.5) | 218 (76.4) | <0.0001 |
| ICU Admission6 | <0.0001 | 0.015 | |||||
| LRMC only | 361 (6.8) | 15 (1.8) | 313 (8.0) | 9 (3.8) | 24 (8.4) | ||
| U.S. MTFs ± LRMC | 965 (18.2) | 29 (3.4) | 879 (22.5) | 11 (4.6) | 46 (16.1) | ||
| Non-ICU | 1180 (22.3) | 135 (15.8) | 940 (24.0) | 43 (18.0) | 62 (21.8) | ||
| Prophylactic antimicrobial use within 48 hours of injury | 3248 (61.3) | 196 (23.0) | 2849 (72.7) | <0.0001 | 44 (18.4) | 159 (55.7) | <0.0001 |
ICU – intensive care unit; IED – improvised explosive device; IQR – Interquartile Range; LRMC – Landstuhl Regional Medical Center; MTFs – military treatment facilities; RBC – packed red blood cells plus whole blood
Data are missing for some of the variables (branch of service missing 47; military rank missing 75; mechanism of injury missing 2; ICU admittance missing 2784). The high amount of ICU admission missing is due to the transfer of approximately half of the patients to non-participating sites.
P-value compares the noncombat and combat-related injury data for Afghanistan. Missing values are not included in calculation.
P-value compares the noncombat and combat-related injury data for Iraq. Missing values are not included in calculation.
Other includes burns, machinery/equipment accidents, noncombat explosions, and crush injuries.
Missing RBC transfusion data are not randomly distributed. Patients with missing RBC data are characterized by lower injury severity scores and shock indices. In addition, the majority of patients with missing RBC data did not sustain a traumatic amputation and were not admitted to the LRMC ICU.
Admission to the ICU is recorded within the first week of care at each facility.