Table 3.

Relative risk (old vs. fresh blood) of infectious complication^* based on average storage duration of RBC units transfused

	21-day cutoff		28-day cutoff		35-day cutoff		Mean Storage Duration (No Cutoff)
	RR (95% CI)	p- value	RR (95% CI)	p- value	RR (95% CI)	p- value	RR (95% CI)	p-value
Age	1.003 (0.97– 1.04)	0.9	1.01 (0.97– 1.05)	0.6	1.002 (0.96– 1.05)	0.9	1.004 (0.97– 1.04)	0.8
Gender
- Female	Reference		Reference		Reference		Reference
- Male	1.66 (0.57– 4.82)	0.4	1.75 (0.14– 4.80)	0.3	1.58 (0.54– 4.59)	0.4	1.63 (0.58– 4.57)	0.3
MSDRGWt	1.43 (1.18– 1.75)	<0.001	1.32 (1.20– 1.44)	<0.001	1.28 (1.18– 1.38)	<0.001	1.33 (1.21– 1.48)	<0.001
BMI	1.11 (1.05– 1.17)	<0.001	1.11 (1.04– 1.18)	0.001	1.10 (1.03– 1.16)	0.001	1.10 (1.04– 1.17)	0.001
Average Storage Duration - <21 days - ≥21 days - <28 days - ≥28 days - <35 days - ≥35 days - Continuous variable (per day)	Reference 10.02 (0.51– 196.33)	0.1	Reference 2.69 (1.18– 6.14)	0.02	Reference 2.83 (1.42– 5.66)	0.003	1.08 (1.01– 1.17)	0.03

^*Infectious complication defined as any of the following: C. difficile, sepsis, surgical-site infection, pyelonephritis, or drug-resistant infection.

MSDRGWt- casemix index

BMI- body mass index