Demographic and clinical characteristics of the study sample, and the two subgroups with Glasgow Outcome Scale—Extended (GOSE) 8 (upper good recovery)
| N (%) | P value | |||
| Study sample (n=1554) | GOSE 8a (n=301) | GOSE 8b (n=302) | ||
| Age | ||||
| Mean (SD) | 47.9 (18.8) | 47.5 (18.9) | 46.8 (21.2) | 0.663 |
| Sex | ||||
| Female | 513 (33%) | 94 (31%) | 77 (25%) | 0.141 |
| Male | 1041 (67%) | 207 (69%) | 225 (75%) | |
| Race | ||||
| Caucasian | 1465 (97%) | 292 (98%) | 288 (98%) | 1 |
| Other | 38 (3%) | 6 (2%) | 6 (2%) | |
| Missing | 51 | 3 | 8 | |
| Highest level of education | ||||
| Primary | 182 (13%) | 29 (10%) | 44 (16%) | 0.056 |
| Secondary | 468 (33%) | 90 (32%) | 90 (33%) | |
| Training | 300 (21%) | 59 (21%) | 38 (14%) | |
| College | 461 (33%) | 106 (37%) | 99 (37%) | |
| Missing | 143 | 17 | 31 | |
| Employment Status | ||||
| Working (full or part time) | 852 (58%) | 176 (60%) | 139 (49%) | 0.032 |
| Not working | 117 (8%) | 15 (5%) | 19 (7%) | |
| Retired | 317 (22%) | 65 (22%) | 73 (26%) | |
| Student/homemaker | 180 (12%) | 36 (12%) | 54 (19%) | |
| Missing | 88 | 9 | 17 | |
| Marital status | ||||
| Partnered | 805 (54%) | 161 (55%) | 149 (51%) | 0.707 |
| Previously partnered | 207 (14%) | 36 (12%) | 37 (13%) | |
| Single/other | 469 (32%) | 98 (33%) | 105 (36%) | |
| Missing | 73 | 6 | 11 | |
| Care pathway | ||||
| Emergency room | 346 (22%) | 179 (60%) | 42 (14%) | <0.001 |
| Admitted to hospital | 588 (38%) | 109 (36%) | 153 (51%) | |
| Intensive care unit | 620 (40%) | 13 (4%) | 107 (35%) | |
| ASA preinjury physical health | ||||
| Healthy patient | 943 (61%) | 183 (61%) | 205 (69%) | 0.159 |
| Mild systemic disease | 469 (30%) | 93 (31%) | 73 (24%) | |
| Severe systemic disease | 129 (8%) | 22 (7%) | 21 (7%) | |
| Missing | 13 | 3 | 3 | |
| Cause of injury | ||||
| Road traffic accident | 671 (44%) | 97 (33%) | 109 (37%) | 0.549 |
| Fall | 644 (42%) | 150 (51%) | 137 (46%) | |
| Violence/assault | 87 (6%) | 21 (7%) | 26 (9%) | |
| Other | 124 (8%) | 29 (10%) | 25 (8%) | |
| Missing/unknown | 28 | 4 | 5 | |
| GCS score at baseline | ||||
| 3-8 | 224 (15%) | 28 (10%) | <0.001 | |
| 9-12 | 107 (7%) | 29 (10%) | ||
| 13–15 | 1181 (78%) | 301 (100%) | 227 (80%) | |
| Missing | 42 | 18 | ||
| CT imaging abnormality | ||||
| Absent | 654 (44%) | 301 (100%) | 55 (21%) | <0.001 |
| Present | 843 (56%) | 213 (79%) | ||
| Missing/uninterpretable | 57 | 34 | ||
| Head and neck AIS1 | ||||
| No injury/minor injury | 284 (18%) | 131 (44%) | 27 (9%) | <0.001 |
| Moderate injury | 231 (15%) | 99 (33%) | 39 (13%) | |
| Serious injury | 523 (34%) | 63 (21%) | 148 (49%) | |
| Severe injury | 271 (17%) | 5 (2%) | 52 (17%) | |
| Critical injury/unsurvivable injury | 245 (16%) | 3 (1%) | 36 (12%) | |
| Major extracranial injury2 | ||||
| Absent | 1029 (66%) | 254 (84%) | 225 (75%) | 0.004 |
| Present | 525 (34%) | 47 (16%) | 77 (26%) | |
| GOSE at 6 months | ||||
| 3/4 Severe disability | 115 (7%) | |||
| 5 Lower moderate disability | 184 (12%) | |||
| 6 Upper moderate disability | 250 (16%) | |||
| 7 Lower good recovery | 402 (26%) | |||
| 8 Upper good recovery | 603 (39%) | 301 (100%) | 302 (100%) | |
GOSE 8b consists of remaining patients with upper good recovery. Tests for significance are for comparison of groups GOSE 8a and GOSE 8b.
GOSE 8a is used as a reference in subsequent analyses, and consists of patients with Glasgow Coma Scale (GCS)=15 at recruitment and no abnormality on early CT.
*Head and neck AIS=maximum Abbreviated Injury Score for head, neck and cervical regions.
†Any non-head and neck AIS≥3 (serious injury).