MAPT and delirium: Ballweg et al. (2021) (n = 114, mixed surgical cases) measured total tau in plasma at multiple time points and reported that the change in plasma total tau was greater in patients with POD and correlated with delirium severity. Baek et al. (2023) (n = 91, orthopedic) measured total tau in urine extracellular vesicles (from urine collected postoperatively) and found that total tau was higher in patients who developed POD vs. those who did not.