The goal of this observational study is to establish a standardized multicenter cohort and develop and validate clinically interpretable models for perioperative risk stratification, brain-state risk prediction, objective pain assessment, sleep-pain-delirium association analysis, and longer-term prognosis.The main questions it aims to answer are:
Can clinically interpretable predictive models be developed for perioperative risk stratification and brain-state changes? What are the associations among objective pain measures, sleep quality, and postoperative delirium? Are these perioperative factors associated with longer-term patient outcomes? This is a multicenter cohort study without a separate comparator group. Participants will undergo routine perioperative clinical assessments and standardized follow-up evaluations according to the study protocol.