Table 1.
Study population and clinical covariates
| Variable | ALI (n = 142) | Non-ALI (n = 325) | p -value |
|---|---|---|---|
| Age, years |
39 ± 19 |
37 ± 18 |
0.35 |
| Male, n (%) |
115 (81%) |
249 (77%) |
0.30 |
| African ancestry, n (%) |
61 (43%) |
161 (48%) |
0.29 |
| European ancestry, n (%) |
74 (51%) |
150 (43%) |
0.14 |
| Era of injury 1999 – 2003, n (%) |
85 (60%) |
160 (49%) |
0.07 |
|
Injury Factors | |||
| Blunt trauma, n (%) |
101 (71%) |
218 (67%) |
0.39 |
| ISS |
26 ± 8 |
24 ± 7 |
0.008 |
| APACHE III † |
64 ± 24 |
58 ± 18 |
0.004 |
| Pulmonary contusion, n (%) |
54 (38%) |
76 (24%) |
0.0013 |
|
Treatment Factors | |||
| Total PRBC 1st 24 h, units (Range) |
3.16 (0 – 19) |
1.56 (0 – 27) |
<0.001 |
| Mechanical ventilation, n (%) |
142 (100%) |
238 (73%) |
<0.001 |
|
Outcomes | |||
| Mortality, n (%) |
35 (25%) |
24 (7%) |
<0.001 |
| Hospital length of stay, days | 22 (11 – 36) | 13 (8 – 26) | <0.001 |
Most continuous variables are presented as mean ± standard deviation, and categorical variables are shown as number (n) and percentage of total population. Hospital length of stay is displayed as median (interquartile range) due to a skewed distribution. ISS: injury severity scale; APACHE III †: Acute physiology and chronic health evaluation, modified to omit the arterial blood gas oxygenation criterion given its collinearity with ALI; PRBC: packed red blood cell transfusion. Blunt trauma is opposed to penetrating trauma. Statistics shown reflect the results of binomial testing, Student’s T test, or nonparametric testing (Wilcoxon rank sum) as appropriate given the data distributions.