Figure 1.

Conceptual model of dynamic relationship between packed red blood cell age and volume, and 24-hour mortality status.

A) This graph depicts three examples of patients who have similar injury severities and receive the same volume of packed red blood cells, but different volumes of packed red blood cells in each age category. We hypothesize that severely injured patients who receive more older packed red blood cell units experience a greater likelihood of mortality.

B) Example of analysis with categorization of packed red blood cell volume (units) per age group transfused to each patient.