ALB and anemia: As shown in Table 1, there were several preoperative characteristics significantly different from the two groups (delirium versus non-delirium), including the age (older in the delirium group), activities of daily living score (lower in the delirium group), preoperative MMSE score (lower in the delirium group), anemia rate (higher in the delirium group), white blood cell (higher in the delirium group), blood urea nitrogen (higher in the delirium group), and albumin (lower in the delirium group).