GPT and delirium: <h4>Objective</h4>To investigate the association between the preoperative serum aspartate aminotransferase to alanine aminotransferase (AST/ALT) ratio and postoperative delirium (POD) and 3-year mortality in POD patients.<h4>Methods</h4>A total of 538 clinical participants were enrolled from the Perioperative Neurocognitive Disorder and Biomarkers Lifestyle (PNDABLE) study.