Table 1.
Patient characteristics and outcome
| All (N = 486) | Mild TBI (N = 354) | Moderate TBI (N = 43) | Severe TBI (N = 78) | Very severe TBI (N = 51) | p value* | |
|---|---|---|---|---|---|---|
| Male | 294 (60.5) | 211 (59.6) | 25 (58.1) | 54 (69.2) | 36 (70.6) | 0.265 |
| Age (years) | 56.1 ± 22.4 | 56.6 ± 22.2 | 58.5 ± 22.4 | 52.2 ± 22.6 | 50.9 ± 23.3 | 0.222 |
| ≤ 18 | 25 (5.1) | 21 (5.9) | 1 (2.3) | 2 (2.6) | 2 (3.9) | 0.467 |
| 19–64 | 255 (52.5) | 184 (52.0) | 21 (48.8) | 46 (59.0) | 30 (58.8) | |
| ≥ 65 | 206 (42.4) | 149 (42.1) | 21 (48.8) | 30 (38.5) | 19 (37.3) | |
| Stratum | < 0.001 | |||||
| Admission | 319 (65.6) | 288 (81.4) | 16 (37.2) | 9 (11.5) | 5 (9.8) | |
| ICU | 167 (34.4) | 66 (18.6) | 27 (62.8) | 69 (88.5) | 46 (90.2) | |
| Location of injury | 0.137 | |||||
| Street/highway | 273 (56.2) | 201 (56.8) | 22 (51.2) | 45 (57.7) | 31 (60.8) | |
| Home/domestic | 153 (31.5) | 113 (31.9) | 11 (25.6) | 25 (32.1) | 15 (29.4) | |
| Work/school | 14 (2.9) | 8 (2.3) | 5 (11.6) | 1 (1.3) | 1 (2.0) | |
| Sport/recreational | 18 (3.7) | 14 (4.0) | 2 (4.7) | 1 (1.3) | 0 (0.0) | |
| Public location | 25 (5.1) | 15 (4.2) | 3 (7.0) | 6 (7.7) | 4 (7.8) | |
| Other/unknown | 2 (0.6) | 3 (0.9) | 0 (0.0) | 0 (0) | 0 (0.0) | |
| Cause of injury | 0.136 | |||||
| Road traffic accident | 176 (36.2) | 125 (35.3) | 14 (32.6) | 35 (44.9) | 25 (49.0) | |
| Incidental fall | 264 (54.3) | 200 (56.5) | 21 (48.8) | 35 (44.9) | 20 (39.2) | |
| Non-intentional injury | 12 (2.5) | 8 (2.3) | 2 (4.7) | 1 (1.3) | 1 (2.0) | |
| Violence/assault | 10 (2.1) | 8 (2.3) | 2 (4.7) | 0 (0.0) | 0 (0.0) | |
| Suicide attempt | 3 (0.6) | 0 (0.0) | 1 (2.3) | 2 (2.6%) | 2 (3.9) | |
| Other/unknown | 21 (4.3) | 13 (3.6) | 3 (7.0) | 5 (6.4) | 3 (5.9) | |
| Glasgow Coma Score | 12.7 ± 3.8 | 14.7 ± 0.6 | 10.6 ± 0.9 | 4.7 ± 1.9 | 3.5 ± 0.7 | N/A |
| GCS Motor score | 5.3 ± 1.6 | 6.0 ± 0.4 | 5.0 ± 1.3 | 2.3 ± 1.7 | 1.4 ± 0.8 | |
| GCS 13–15 | 354 (72.8) | 354 (100) | – | – | – | |
| GCS 9–12 | 43 (8.8) | – | 43 (100) | – | – | |
| GCS 3–8 | 78 (16.1) | – | – | 78 (100) | – | |
| GCS 3–5 | 51 (10.5) | – | – | 51 (65.4) | 51 (100) | |
| Missing | 11 (2.3) | – | – | – | – | |
| Pupillary abnormalities | < 0.001 | |||||
| Both reacting | 423 (87.0) | 343 (98.0) | 39 (90.7) | 38 (48.7) | 19 (37.3) | |
| One reacting | 14 (2.9) | 5 (1.4) | 2 (4.7) | 7 (9.0) | 4 (7.8) | |
| Both non-reacting | 37 (7.6) | 2 (0.6) | 2 (4.7) | 33 (42.3) | 28 (54.9) | |
| Missing | 12 (2.5) | 4 (1.1) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Findings first CT scan | ||||||
| Intracranial abnormalities | 263 (54.1) | 160 (45.2) | 30 (69.8) | 68 (87.2) | 43 (84.3) | < 0.001 |
| Contusion | 130 (26.7) | 68 (19.2) | 22 (51.2) | 38 (48.7) | 26 (51.0) | < 0.001 |
| Traumatic SAH | 185 (38.1) | 101 (28.5) | 26 (60.5) | 56 (71.8) | 37 (72.5) | < 0.001 |
| Epidural hematoma(s) | 47 (9.7) | 27 (7.6) | 7 (16.3) | 13 (16.7) | 9 (17.6) | < 0.001 |
| Subdural hematoma(s) | 136 (28.0) | 68 (19.2) | 22 (51.2) | 43 (55.1) | 28 (54.9) | < 0.001 |
| Skull fracture(s) | 180 (37.0) | 97 (27.4) | 25 (58.1) | 55 (70.5) | 39 (76.5) | < 0.001 |
| Compressed basal cisterna | 88 (18.1) | 30 (8.5) | 9 (20.9) | 47 (60.3) | 34 (66.7) | < 0.001 |
| Midline shift > 5 mm | 65 (13.4) | 21 (5.9) | 10 (23.3) | 31 (39.7) | 20 (39.2) | < 0.001 |
| Mass lesion > 25 cc | 80 (16.5) | 26 (7.3) | 14 (32.6) | 37 (47.4) | 26 (51.0) | < 0.001 |
| Uninterpretable** | 10 (2.1) | 5 (1.4) | 4 (9.3) | 0 (0.0) | 0 (0.0) | |
| Injury severity | ||||||
| Brain Injury AIS | 3.1 ± 1.2 | 2.7 ± 0.9 | 3.7 ± 1,2 | 4.6 ± 1.2 | 4.8 ± 1.2 | < 0.001 |
| ISS | 20 ± 16 | 15 ± 9 | 22 ± 16 | 39 ± 22 | 43 ± 21 | < 0.001 |
| In-hospital mortality | 60 (12.3) | 8 (2.3) | 8 (18.6) | 42 (53.8) | 32 (62.7) | < 0.001 |
| GOSE at 6 months | 5.72 ± 2.55 | 6.5 ± 1.8 | 4.6 ± 2.7 | 2.9 ± 2.7 | 2.4 ± 2.5 | |
| Favourable/unfavourable*** | 72.9%/27.1% | 85.4%/14.6% | 55.3%/44.7% | 29.0%/71.0% | 19.6%/80.4% | < 0.001 |
| 1 | 73 (15.0) | 15 (4.2) | 10 (23.3) | 45 (57.7) | 34 (66.7) | < 0.001 |
| 2/3 | 17 (3.5) | 10 (2.8) | 6 (14.0) | 1 (1.3) | 0 (0.0) | |
| 4 | 23 (4.7) | 19 (5.4) | 1 (2.3) | 3 (3.8) | 3 (5.9) | |
| 5 | 25 (5.1) | 18 (5.1) | 5 (11.6) | 2 (2.6) | 1 (2.0) | |
| 6 | 38 (7.8) | 31 (8.8) | 4 (9.3) | 3 (3.8) | 1 (2.0) | |
| 7 | 110 (22.6) | 93 (26.3) | 4 (9.3) | 10 (12.8) | 4 (7.8) | |
| 8 | 131 (27.0) | 115 (32.5) | 8 (18.6) | 5 (6.4) | 3 (5.9) | |
| Loss to follow-up | 69 (14.2) | 53 (15.0) | 5 (11.6) | 9 (11.5) | 5 (9.8) | 0.650 |
Values are reported as: Number (percentage). Mean ± SD. AIS, abbreviated injury scale; CT scan, computed tomography scan; GCS, Glasgow Coma Score; GOSE, Glasgow Outcome Score–Extended; ICU, intensive care unit; SAH, subarachnoid haemorrhage
*p values were derived from ANOVA for continuous characteristics and χ2 statistics for categorical characteristics, comparing TBI severity categories (severe TBI, moderate TBI, mild TBI). The p value assessed compatibility with the null hypothesis of no differences between TBI severity categories
**Numbers from TBI severity subgroups do not always match the numbers that are reported for all patients because baseline GCS data was missing for 11 patients. Also, data from 1 CT scan could not be retrieved
***Calculated excluding missing. Favourable and unfavourable were defined as GOSE 5–8 and GOSE 1–4 respectively