Distribution patterns of recalled blood products. (A) Overall distribution density map of recalled blood products. Distribution density, defined as kilometers traveled by recalled products per square kilometer of geographic area, was constructed using the spatial density of lines connecting the origin and destination locations for all recalled blood products. Distribution network maps for various blood products were constructed using the XY to line function in ArcGIS. Each line on the map represents the linear connection between the origin (Zip codes) and destination (geographic center of the state) locations of recalled blood products. A recall event originating at a single location can have multiple destinations, and consequently there will be multiple lines originating from that location. (B) Number of destinations for affected units in a recall event for different blood products. Significance was estimated using the Kruskal-Wallis test, P < 2.2 × 10⁻¹⁶. (C) Distance traveled by affected units in a recall event for different blood products. Distances between recall origin (Zip codes) and destination (geographic center of destination states) locations were calculated using XY-to-line function in ArcGis. Significance was estimated using Kruskal-Wallis test, P < 2.2 × 10⁻¹⁶.