We tested four models: one with all serum soluble factors, one with blood phenotyping data, one combining both, and one including the 12 parameters previously associated with delirium (IL-1α, IL-22, IL-21, CCL11, CXCL1, CXCL13, HGF, VEGF-A, CXCR3 + CD4 + T cells, IgM + unswitched memory B cells, exhausted B cells, HLA-DR + activated T cells). Here, IL21 is linked to delirium.