Inclusion Criteria:  age ≥ 70 years having non-cardiac and non-cranial surgery in the Tel-Aviv Medical Center  Exclusion Criteria:  Known psychiatric or severe neurologic disorder (e.g., Alzheimer's disease, past stroke) Preoperative cognitive decline (MiniCog test result < 3 points) Not planned to be extubated and awaken at surgery conclusion Known inability to cooperate with postoperative delirium screening (language barrier, aphasia)