Table 3.

Measure of association for primary and secondary outcomes

	OR (95% CI)	P value
Empyema	1.51 (0.42 to 5.42)	0.53
Pneumonia	1.61 (0.86 to 3.03)	0.14
Death	0.55 (0.25 to 1.22)	0.14
Pneumonia or death	1.17 (0.77 to 1.77)	0.46
Clostridium difficile colitis	0.65 (0.09 to 4.48)	0.66

	Rate ratio (95% CI)	P value
ICULOS	1.35 (0.93 to 1.96)	0.11
Hospital LOS	1.15 (0.95 to 1.40)	0.15
Ventilation days	1.43 (0.86 to 2.39)	0.17

Logistic regression for binary outcomes and negative binomial regression for count outcomes, both with random effects of matched pairs and trauma centers.

ICULOS, intensive care unit length of stay.