Table 1. Study Population and Acute-Injury Characteristics for Severe Traumatic Brain Injury (TBI) and Moderate TBI Groups.
| Characteristic | Participants, No. (%) | P valuec | |
|---|---|---|---|
| With severe TBIa (n = 362) | With moderate TBIb (n = 122) | ||
| Age, median (IQR), y | 35.5 (25-53) | 38 (25-53) | .67 |
| Unknown, No. | 1 | 0 | |
| Male | 283 (78.2) | 98 (80.3) | .70 |
| Female | 79 (21.8) | 24 (19.7) | |
| Race | |||
| White | 275 (76.0) | 92 (75.4) | .64 |
| Black | 49 (13.5) | 20 (16.4) | |
| Other/unknown | 38 (10.5) | 10 (8.2) | |
| Hispanic ethnicity | |||
| No | 286 (82.2) | 89 (73.0) | .04 |
| Yes | 62 (17.8) | 33 (27.0) | |
| Unknown, No. | 14 | 0 | |
| Insurance | |||
| Commercial | 184 (58.8) | 63 (58.9) | .72 |
| None | 53 (16.9) | 15 (14.0) | |
| Medicare/other | 76 (24.3) | 29 (27.1) | |
| Unknown, No. | 49 | 15 | |
| Education, mean (SD), y | 12.6 (2.6) | 12.9 (2.8) | .36 |
| Unknown, No. | 54 | 12 | |
| Employment | |||
| Full-time | 173 (54.2) | 63 (56.3) | .30 |
| Part-time | 38 (11.9) | 20 (17.9) | |
| Occasional, special, or unemployed | 34 (10.7) | 11 (9.8) | |
| Retired, disabled, or not working | 49 (15.4) | 14 (12.5) | |
| Other | 25 (8) | 4 (4) | |
| Unknown, No. | 43 | 10 | |
| Living situation | |||
| Independent living | 224 (70.0) | 81 (71.1) | .84 |
| Living with others | 88 (27.5) | 29 (25.4) | |
| Homeless | 3 (0.9) | 2 (1.8) | |
| Other | 5 (1.6) | 2 (1.8) | |
| Unknown, No. | 42 | 8 | |
| Previous TBI | |||
| No | 246 (85.4) | 81 (79.4) | .16 |
| Yes | 42 (14.6) | 21 (20.6) | |
| Unknown, No. | 74 | 20 | |
| Neurologic disorder other than TBI | |||
| No | 325 (90.0) | 109 (89.3) | .86 |
| Yes | 36 (10.0) | 13 (10.7) | |
| Unknown, No. | 1 | 0 | |
| Neurodevelopmental disorder | |||
| No | 342 (94.7) | 116 (95.1) | >.99 |
| Yes | 19 (5.3) | 6 (4.9) | |
| Unknown, No. | 1 | 0 | |
| Mental health history | |||
| No | 280 (77.3) | 99 (81.1) | .45 |
| Yes | 82 (22.7) | 23 (18.9) | |
| Unknown, No. | 0 | 0 | |
| Headache history | |||
| No | 358 (99.2) | 119 (97.5) | .17 |
| Yes | 3 (0.8) | 3 (2.5) | |
| Unknown, No. | 1 | 0 | |
| Migraine history | |||
| No | 354 (98.1) | 118 (96.7) | .48 |
| Yes | 7 (1.9) | 4 (3.3) | |
| Unknown, No. | 1 | 0 | |
| Cause of injury | |||
| Motor vehicle crash, occupant | 100 (27.6) | 30 (24.6) | .15 |
| Motorcycle crash | 53 (14.6) | 14 (11.5) | |
| Motor vehicle crash, cyclist or pedestrian | 52 (14.4) | 17 (13.9) | |
| Fall | 84 (23.2) | 32 (26.2) | |
| Assault | 21 (5.8) | 16 (13.1) | |
| Other/unknown | 52 (14.4) | 13 (10.7) | |
| Loss of consciousness | |||
| No | 3 (0.9) | 9 (8.0) | <.001 |
| Yes | 337 (99.1) | 103 (92.0) | |
| Unknown, No. | 22 | 10 | |
| Posttraumatic amnesia | |||
| No | 19 (8.3) | 3 (3.0) | .14 |
| Yes | 210 (91.7) | 92 (97.0) | |
| Unknown, No. | 133 | 27 | |
| Peripheral injuryd | |||
| No | 35 (9.8) | 10 (8.3) | .72 |
| Yes | 322 (90.2) | 111 (91.7) | |
| Unknown, No. | 5 | 1 | |
| Glasgow Coma Scale score in emergency department | |||
| Mean (SD) | 4.3 (1.8) | 10.4 (1.1) | NA |
| Median (IQR) | 3 (3-6) | 10 (9-12) | |
| Abbreviated Injury Scale head and neck score | |||
| Mean (SD) | 4.0 (1.2) | 3.4 (1.3) | <.001 |
| Median (IQR) | 4 (3-5) | 4 (3-4) | |
| Unknown, No. | 13 | 5 | |
| Injury Severity Score total score | |||
| Mean (SD) | 25.6 (11.5) | 20.1 (9.4) | .001 |
| Median (IQR) | 26 (17-33) | 20 (13-27) | |
| Unknown, No. | 13 | 5 | |
| Injury Severity Score peripheral score | |||
| Mean (SD) | 8.2 (9.4) | 5.7 (7.4) | .02 |
| Median (IQR) | 5 (1-14) | 1 (1-9) | |
| Unknown, No. | 13 | 5 | |
| Highest level of care | |||
| Emergency department | 0 | 0 | .003 |
| Inpatient unit | 7 (2.0) | 10 (8.4) | |
| Intensive care unit | 351 (98.0) | 109 (91.6) | |
| Unknown, No. | 4 | 3 | |
| Interventions | |||
| External ventricular drain | |||
| No | 261 (72.1) | 97 (79.5) | .12 |
| Yes | 101 (27.9) | 25 (20.5) | |
| Shunt | 10 (3) | 1 (1) | |
| No | 352 (97.2) | 121 (99.2) | .31 |
| Yes | 10 (2.8) | 1 (0.8) | |
| Craniectomy | 102 (28) | 25 (20) | |
| No | 260 (71.8) | 97 (79.5) | .10 |
| Yes | 102 (28.2) | 25 (20.5) | |
| Craniotomy | 42 (12) | 11 (9) | |
| No | 320 (88.4) | 111 (91.0) | .51 |
| Yes | 42 (11.6) | 11 (9.0) | |
| Length of hospitalizatione | |||
| Mean (SE) | 25.9 (2.4) | 15.6 (1.4) | <.001 |
| Median (SE) | 17.8 (0.8) | 16.6 (0.8) | |
| Unknown, No. | 9 | 6 | |
a
Glasgow Coma Scale scores of 3 to 8.
b
Glasgow Coma Scale scores of 9 to 12.
c
P value from Mann-Whitney and Fisher exact tests as appropriate.
d
Peripheral injury was defined as either having a peripheral (below the neck) Injury Severity Score greater than 0 or ever reporting peripheral injuries on a Glasgow Outcome Scale–Extended or Disability Rating Scale assessment.
e
Days to patients being discharged alive (survival analysis with deaths censored). Length-of-stay analysis treats all of the deaths as censored values, with unknown values reflecting incomplete admission or discharge information.