Table 1.
Descriptive statistics of the study population (n = 44,984) presented in four different groups from left to right: (1) Patients excluded from the main analysis; (2) Patients included in the main analysis; (3) Included patients treated at a non-trauma center (NTC); (4) Included patients treated at a trauma center (TC)
| Variable | Levels | Excluded | Included | NTC | TC |
|---|---|---|---|---|---|
| Total nr of registrations | – | 15,120 | 29,864 | 14,656 | 15,208 |
| Sexab | Male | 9503 (62.9)* | 19,356 (64.8) | 9276 (63.3)* | 10,080 (66.3) |
| Female | 5569 (36.8)* | 10,508 (35.2) | 5380 (36.7)* | 5128 (33.7) | |
| Unknown | 48 (0.3)* | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Age (years)ab | 0–15 | 2010 (13.3)* | 3442 (11.5) | 1726 (11.8) | 1716 (11.3) |
| 16–45 | 7768 (51.4)* | 14,231 (47.7) | 6816 (46.5)* | 7415 (48.8) | |
| 46–60 | 2501 (16.5)* | 5559 (18.6) | 2642 (18.0)* | 2917 (19.2) | |
| 61–75 | 1788 (11.8)* | 3902 (13.1) | 2042 (13.9)* | 1860 (12.2) | |
| 76–107 | 960 (6.3)* | 2730 (9.1) | 1430 (9.8)* | 1300 (8.5) | |
| Unknown | 93 (0.6)* | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Dominant type of injuryab | Blunt | 13,153 (87.0)* | 27,517 (92.1) | 13,863 (94.6)* | 13,654 (89.8) |
| Penetrating | 722 (4.8)* | 2347 (7.9) | 793 (5.4)* | 1554 (10.2) | |
| Unknown | 1245 (8.2)* | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Mechanism of injuryab | Motor vehicle crash | 5372 (35.5)* | 8548 (28.6) | 5117 (34.9)* | 3431 (22.6) |
| Motorcycle | 1052 (7.0)* | 2325 (7.8) | 1059 (7.2)* | 1266 (8.3) | |
| Bicycle | 951 (6.3)* | 2411 (8.1) | 1137 (7.8)* | 1274 (8.4) | |
| Pedestrian | 351 (2.3)* | 1027 (3.4) | 346 (2.4)* | 681 (4.5) | |
| Traffic other | 299 (2.0)* | 493 (1.7) | 339 (2.3)* | 154 (1.0) | |
| Shot | 182 (1.2) | 415 (1.4) | 74 (0.5)* | 341 (2.2) | |
| Stab | 462 (3.1)* | 1657 (5.5) | 492 (3.4)* | 1165 (7.7) | |
| Blunt object | 711 (4.7)* | 1895 (6.3) | 679 (4.6)* | 1216 (8.0) | |
| Low fall < 3 m | 1215 (8.0)* | 3312 (11.1) | 1426 (9.7)* | 1886 (12.4) | |
| High fall > 3 m | 2709 (17.9)* | 6501 (21.8) | 3111 (21.2)* | 3390 (22.3) | |
| Explosion | 43 (0.3) | 70 (0.2) | 40 (0.3) | 30 (0.2) | |
| Other | 595 (3.9) | 1134 (3.8) | 805 (5.5)* | 329 (2.2) | |
| Unknown | 1178 (7.8)* | 76 (0.3) | 31 (0.2) | 45 (0.3) | |
| ISSab | 0 | 6712 (44.4) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| 1–8 | 5101 (33.7)* | 20,470 (68.5) | 10,669 (72.8)* | 9801 (64.4) | |
| 9–15 | 1496 (9.9) | 5426 (18.2) | 2477 (16.9)* | 2949 (19.4) | |
| 16–24 | 889 (5.9)* | 2156 (7.2) | 886 (6.0)* | 1270 (8.4) | |
| 25–49 | 848 (5.6)* | 1570 (5.3) | 570 (3.9)* | 1000 (6.6) | |
| 50–75 | 73 (0.5) | 242 (0.8) | 54 (0.4)* | 188 (1.2) | |
| Unknown | 1 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Type of transport | Ground ambulance | 8584 (56.8)* | 27,645 (92.6) | 14,006 (95.6)* | 13,639 (89.7) |
| Helicopter ambulance | 230 (1.5)* | 2195 (7.3) | 637 (4.3)* | 1558 (10.2) | |
| Fixed-wing ambulance | 1 (0.0) | 10 (0.0) | 7 (0.0) | 3 (0.0) | |
| Private/public vehicle | 2202 (14.6)* | 1 (0.0) | 1 (0.0) | 0 (0.0) | |
| Walk-in | 1421 (9.4)* | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Police | 153 (1.0)* | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Other | 114 (0.8)* | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Not applicable | 1772 (11.7)* | 6 (0.0) | 2 (0.0) | 4 (0.0) | |
| Unknown | 643 (4.3)* | 7 (0.0) | 3 (0.0) | 4 (0.0) | |
| Transportation time (min)ab | 0–20 | 5223 (34.5)* | 18,176 (60.9) | 7145 (48.8)* | 11,031 (72.5) |
| 20–45 | 2680 (17.7)* | 9253 (31.0) | 5377 (36.7)* | 3876 (25.5) | |
| 45–90 | 642 (4.2)* | 2260 (7.6) | 1979 (13.5)* | 281 (1.8) | |
| > 90 | 97 (0.6) | 175 (0.6) | 155 (1.1)* | 20 (0.1) | |
| Unknown | 6478 (42.8)* | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Hospital typesa | NTC | 8901 (58.9)* | 14,656 (49.1) | 14,656 (100.0) | 0 (0.0) |
| TC | 6219 (41.1)* | 15,208 (50.9) | 0 (0.0) | 15,208 (0.0) | |
| Unknown | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Transferab | Direct | 11,528 (76.2)* | 27,307 (91.4) | 12,999 (88.7)* | 14,308 (94.1) |
| Transferred | 2372 (15.7)* | 2557 (8.6) | 1657 (11.3)* | 900 (5.9) | |
| Unknown | 1220 (8.1)* | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| GCSab | 13–15 (minor) | 10,142 (67.1)* | 27,347 (91.6) | 13,817 (94.3)* | 13,530 (89.0) |
| 9–12 (moderate) | 194 (1.3)* | 876 (2.9) | 288 (2.0)* | 588 (3.9) | |
| 3–8 + intubated (severe) | 943 (6.2)* | 1641 (5.5) | 551 (3.8)* | 1090 (7.2) | |
| Unknown | 3841 (25.4)* | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Highest level of careab | Emergency department | 7282 (48.2)* | 11,410 (38.2) | 5998 (40.9)* | 5412 (35.6) |
| General ward | 2584 (17.1)* | 7697 (25.8) | 3976 (27.1)* | 3721 (24.5) | |
| Operation theatre | 626 (4.1)* | 2207 (7.4) | 842 (5.7)* | 1365 (9.0) | |
| High dependency unit | 951 (6.3)* | 3315 (11.1) | 1159 (7.9)* | 2156 (14.2) | |
| ICU | 2480 (16.4)* | 5234 (17.5) | 2680 (18.3)* | 2554 (16.8) | |
| Unknown | 1197 (7.9)* | 1 (0.0) | 1 (0.0) | 0 (0.0) | |
| Mortality 30-dayab | Dead | 394 (2.6)* | 1196 (4.0) | 495 (3.4)* | 701 (4.6) |
| Alive | 13,126 (86.8)* | 28,668 (96.0) | 14,161 (96.6)* | 14,507 (95.4) | |
| Unknown | 1600 (10.6)* | 0 (0.0) | 0 (0.0) | 0 (0.0) |
The data are presented as number of cases and in column percentages. Statistical comparisons have been made between the excluded and included group, and the NTC and TC groups, respectively
ISS Injury Severity Score, GCS Glasgow Coma Scale, ICU Intensity care unit
a Statistical significance with Person Chi Square test, comparing column proportions between excluded and included patients
*Statistical significance with Z-test, comparing pairwise column proportions between excluded and included patients (denoted in column “Excluded”) and NTC and TC (denoted in column “NTC”), respectively
b Statistical significance with Person Chi Square test, comparing column proportions between NTC and TC