MAPT and delirium: When differentiating between clinical subtypes of delirium, levels of Tau-protein and the ratio of Tau/Aβ1–42 was significantly higher in the hypoactive delirium group compared to the non-delirium group (median 90 (IQR 46–224) vs. 31.25 (IQR 31.25–52) pg/mL, p = 0.009 and median 1.42 (IQR 0.90–2.57) vs. 0.69 (IQR 0.54–0.96), p = 0.003, respectively; see Table 3).