Figure 1.

Multivariate analysis of independent transfusion risk factor for acute respiratory distress syndrome (ARDS). After covariates were adjusted for, the amount of blood exposure remained statistically significantly associated with an increasing risk of developing ARDS. Adjusted odds ratios relative to no transfusion were as follows: 1 to 2 units, 2.25 (95% confidence interval [CI], 1.44 to 3.50); 3 to 4 units, 2.71 (95% CI, 1.58 to 4.65); and more than 4 units, 5.22 (95% CI, 3.12 to 8.74) (p < 0.05 for all). *Covariates adjusted for in the multivariate logistic model included age, admitting diagnosis, intensive care unit type, nutritional status, process of care, severity of illness, and laboratory data.