TABLE 3.

Associations between PRBC age and 24-hour mortality. Data in cells reflect odds ratios (OR) for death per additional PRBC unit received. Odds ratios estimated from random effects models, accounting for clustering by study site. Multivariable models adjusted for patient age, sex, race, mechanism of injury, Injury Severity Score, Revised Trauma Score and PROPPR trial treatment group. Model for All Patients additionally adjusted for total PRBC units transfused in the first 24 hours after admission. PRBC = Packed red blood cell.

Variable	Unadjusted OR (95% CI)	Multivariable Adjusted – All Patients OR (95% CI)	Multivariable Adjusted – Patients receiving ≥10 units PRBCs (n=313) OR (95% CI)	Multivariable Adjusted - Patients receiving <10 units PRBCs (n=361) OR (95% CI)
PRBC Age Category
0–7 days	0.96 (0.89–1.06)	0.97 (0.88–1.08)	0.96 (0.86–1.08)	0.95 (0.68–1.32)
8–14	1.06 (1.03–1.10)	1.04 (0.99–1.09)	1.04 (0.99–1.09)	1.00 (0.79–1.27)
15–21	1.02 (0.98–1.05)	1.02 (0.98–1.06)	1.02 (0.98–1.06)	0.86 (0.64–1.14)
22+	1.04 (1.02–1.07)	1.05 (1.01–1.08)	1.05 (1.01–1.08)	1.05 (0.83–1.32)
Total PRBC Units
1–10		Referent
11–20		1.43 (0.77–2.65)
21+		1.09 (0.40–2.98)
Patient age		1.01 (1.00–1.03)	1.02 (1.00–1.03)	1.02 (0.99–1.04)
Gender (male vs female)		1.23 (0.68–2.21)	1.92 (0.89–4.11)	0.62 (0.22–1.75)
Race
White		Referent	Referent	Referent
Black		1.52 (0.84–2.79)	1.46 (0.68–3.16)	1.36 (0.46–4.06)
Other		0.55 (0.20–1.56)	0.71 (0.21–2.47)	0.27 (0.03–2.29)
Mechanism of injury
Blunt vs. penetrating		1.41 (0.71–2.78)	2.08 (0.97–4.46)	0.86 (0.30–2.44)
Burn vs. penetrating		6.01 (0.98–37.0)	N/A	N/A
Injury Severity Score		1.03 (1.01–1.05)	1.55 (1.11–2.17)	1.32 (0.80–2.17)
Revised Trauma Score		0.66 (0.56–0.77)	0.52 (0.37–0.72)	0.35 (0.22–0.55)
PROPPR trial treatment group		1.45 (0.85–2.50)	1.03 (0.55–1.94)	2.24 (0.97–5.17)