TABLE I.
Treatment Group Means and Proportions (± SD)*
|
P Value
|
||||||
---|---|---|---|---|---|---|---|
t0 (N = 1759) | t1 (N = 540) | t2 (N = 359) | t3 (N = 272) | t4 (N = 139) | Association with Treatment | Association with Mortality | |
Covariates (Wm)† | |||||||
Glasgow Coma Scale score | 12.67 ± 4.22 | 12.69 ± 4.14 | 11.66 ± 4.75 | 10.77 ± 5.13 | 9.68 ± 5.20 | <0.001 | <0.001 |
New Injury Severity Score | 27.35 ± 8.97 | 27.21 ± 8.33 | 29.20 ± 9.62 | 32.31 ± 11.39 | 34.68 ± 14.05 | <0.001 | <0.001 |
Maximum Abbreviated Injury Score, head/neck region | 1.71 ± 1.65 | 1.76 ± 1.69 | 2.01 ± 1.68 | 2.32 ± 1.83 | 2.50 ± 1.94 | <0.001 | <0.001 |
Cardiac comorbidity | 0.13 ± 0.34 | 0.17 ± 0.37 | 0.20 ± 0.40 | 0.28 ± 0.45 | 0.27 ± 0.45 | <0.001 | 0.002 |
Number of serious associated extremity injuries | 1.65 ± 0.94 | 1.42 ± 0.73 | 1.54 ± 0.86 | 1.67 ± 1.01 | 1.68 ± 0.96 | <0.001 | <0.001 |
Arrival between 6 a.m. and 12 p.m. | 0.24 ± 0.43 | 0.07 ± 0.26 | 0.20 ± 0.40 | 0.18 ± 0.39 | 0.22 ± 0.42 | 0.001 | 0.04 |
Age | 31.86 ± 13.73 | 33.12 ± 15.73 | 34.25 ± 15.87 | 34.44 ± 16.33 | 33.38 ± 15.05 | 0.01 | 0.01 |
Bilateral fracture | 0.02 ± 0.14 | 0.00 ± 0.06 | 0.01 ± 0.12 | 0.02 ± 0.12 | 0.02 ± 0.15 | 0.03 | 0.03 |
Teaching hospital | 0.56 ± 0.50 | 0.67 ± 0.47 | 0.58 ± 0.50 | 0.53 ± 0.50 | 0.63 ± 0.49 | 0.38 | 0.15 |
Hospitals from Northeast region | 0.08 ± 0.27 | 0.10 ± 0.30 | 0.09 ± 0.29 | 0.11 ± 0.32 | 0.07 ± 0.26 | 0.54 | 0.00 |
Treated at level-1 trauma center | 0.39 ± 0.49 | 0.39 ± 0.49 | 0.45 ± 0.50 | 0.45 ± 0.50 | 0.48 ± 0.50 | 0.69 | 0.05 |
Cerebrovascular comorbidity | 0.00 ± 0.04 | 0.00 ± 0.04 | 0.01 ± 0.08 | 0.00 ± 0.06 | 0.00 ± 0.00 | 0.74 | 0.01 |
Mortality (95% confidence interval) | 3.7% (2.3% to 5.4%) | 1.9% (0.7% to 3.3%) | 4.2% (2.2% to 6.4%) | 4.4% (2.3% to 6.7%) | 4.3% (0.8% to 8.2%) |
SD = standard deviation. Treatment groups are defined as t0 (twelve hours or less), t1 (more than twelve hours to twenty-four hours), t2 (more than twenty-four hours to forty-eight hours), t3 (more than forty-eight hours to 120 hours), and t4 (more than 120 hours).
Wm = subset of covariates with bivariate associations with mortality (p < 0.2).