MAPT and Alzheimer disease: The lack of consistency even extends to the same investigators: Fong et al. (2021) (n = 59) found a trend towards statistically significantly increased delirium incidence in orthopedic patients meeting amyloid, tau, and neurodegeneration (ATN) classification of AD, but in a separate case–control study (n = 35 matched pairs) failed to find a significant association of preoperative plasma or CSF pTau181 with POD (Fong et al., 2024).