Figure 5 The co-expression heat map. The upper half shows the preoperative hemoglobin levels (PHB) in a column format, with a gradual increase from left to right. Blue indicates the PHB value in the restrictive-threshold group (RG), while red indicates that the PHB value in the liberal-transfusion group (LG). The lower half represents the values of other clinical entries for the same patient that correspond to the PHB of the upper half. In this section, red means high values, blue means low values in the heat map. These values are further divided into LG and RG for comparison, with the corresponding P values displayed on the right side. Software: Xiantao Academic, 2nd Edition, Shanghai Xiantao Data Technology Co, Ltd.