Table 1 Study population characteristics
Alive at 30 days (n=19 758) | Death within 30 days (n=8611) | p-value | Missing data for 30-day mortality (n=1817) | |
|---|---|---|---|---|
Age, years | 53.0 [33.4 to 68.4] | 70.2 [60.0 to 79.8] | <0.001 | 50.0 [30.0 to 67.7] |
Missing, n | 0 | 0 | 0 | |
Heart rate, beats per minute | 90 [77 to 108] | 90 [70 to 110] | <0.001 | 90 [77 to 105] |
Missing, n | 2529 (12.8) | 5073 (58.9) | 431 (23.7) | |
Systolic blood pressure, mmHg | 131 [113 to 151] | 134 [103 to 168] | 0.008 | 130 [112 to 148] |
Missing, n | 2843 (14.4) | 5273 (61.2) | 489 (26.9) | |
Respiratory rate, breaths per minute | 16 [14 to 20] | 16 [12 to 22] | <0.001 | 16 [14 to 20] |
Missing, n | 6783 (34.3) | 5880 (68.3) | 867 (47.8) | |
Oxygen saturation, % | 97 [94 to 99] | 95 [89 to 98] | <0.001 | 97 [95 to 99] |
Missing, n | 3078 (15.6) | 5506 (63.9) | 482 (26.5) | |
Time to HEMS arrival, minutes | 19 [14 to 29] | 19 [14 to 28] | 0.14 | 19 [13 to 28] |
Missing, n | 0 | 0 | 0 | |
Time to EMS arrival, minutes | 11 [8 to 16] | 10 [7 to 15] | <0.001 | 11 [8 to 18] |
Missing, n | 13 427 (68.0) | 4885 (56.7) | 1330 (73.2) | |
GCS | 14 [7 to 15] | 3 [3 to 3] | <0.001 | 14 [7 to 15] |
Missing, n | 1284 (6.5) | 763 (8.9) | 151 (8.3) | |
Cardiac rhythm | <0.001 | |||
Sinus rhythm | 14 187 (71.8) | 2287 (26.6) | 1202 (66.2) | |
SVES, VES (mono) | 85 (0.4) | 30 (0.3) | 6 (0.3) | |
AFlut, AFib, AV block (II–III), VES (poly) | 1376 (7.0) | 779 (9.0) | 99 (5.4) | |
VF, VT, asystole, PEA | 832 (4.2) | 4683 (54.4) | 79 (4.3) | |
Not registered | 1620 (8.2) | 132 (1.5) | 198 (10.9) | |
Paced | 94 (0.5) | 79 (0.9) | 5 (0.3) | |
Missing | 1564 (7.9) | 621 (7.2) | 228 (12.5) | |
Medical facility or nursing home | <0.001 | |||
No | 18 727 (94.8) | 7874 (91.4) | 1757 (96.7) | |
Yes | 1035 (5.2) | 737 (8.6) | 60 (3.3) | |
Missing | 0 | 0 | 0 | |
HEMS vehicle | 0.004 | |||
Ground unita | 9908 (50.1) | 4158 (48.3) | 929 (51.1) | |
Helicopterb | 9850 (49.9) | 4453 (51.7) | 888 (48.9) | |
Missing | 0 | 0 | 0 | |
Number of patients | <0.001 | |||
1 | 19 315 (97.8) | 8577 (99.6) | 1765 (97.1) | |
≥ 2 | 443 (2.2) | 34 (0.4) | 52 (2.9) | |
Missing | 0 | 0 | 0 | |
Sex | <0.001 | |||
Female | 7249 (36.7) | 2791 (32.4) | 531 (29.2) | |
Male | 12 509 (63.3) | 5750 (66.8) | 1002 (55.1) | |
Missing | 0 | 70 (0.8) | 284 (15.6) | |
Patient category | <0.001 | |||
Cardiac arrest | 1404 (7.1) | 5461 (63.4) | 135 (7.4) | |
Trauma | 6480 (32.8) | 915 (10.6) | 643 (35.4) | |
Respiratory failure | 1084 (5.5) | 294 (3.4) | 75 (4.1) | |
Chest pain | 810 (4.1) | 75 (0.9) | 48 (2.6) | |
Stroke | 1125 (5.7) | 821 (9.5) | 82 (4.5) | |
Neurologicalc | 2785 (14.1) | 512 (5.9) | 228 (12.5) | |
Psychiatric or intoxication | 2941 (14.9) | 63 (0.7) | 308 (17.0) | |
Gynaecology and obstetrics | 637 (3.2) | 1 (0.0) | 55 (3.0) | |
Infection | 198 (1.0) | 62 (0.7) | 14 (0.8) | |
Other | 2294 (11.6) | 407 (4.7) | 229 (12.6) | |
Missing | 0 | 0 | 0 |