Demographic and medical characteristics (including age, gender, and education) were evaluated. The modified Charlson's Comorbidity Index (MCCI) was utilized for the medical comorbidities assessment by summing points . POD was evaluated using the Confusion Assessment Method-Intensive Care Unit (CAM-ICU) by calculating CAM scores . POD assessment was performed once a day (in the evening) for the first 3 days and at 7th day after surgery, respectively. A positive POD diagnosis was given when patients had a positive result at least for once within 1 week of the assessment. The intraoperative variables (operation time, anesthesia time, blood loss, etc.), postoperative complications (wound infection, urinary tract infection, pulmonary infection, etc.), and postoperative adverse cardiovascular events (such as myocardial infarction, arrhythmias, and heart failure) were also detailed, recorded, and analyzed.