ALB and delirium: In conclusion, we have found that postoperative delirium is very common is patients with hip fracture, and for patients with age ≥ 75 years, BMI ≥ 24 kg/m2, history of delirium, estimated blood loss ≥ 400 mL, duration of surgery ≥ 120 min, preoperative albumin ≤ 40 g/L and TSH ≤ 2 mU/L, they may have higher risks for the development of postoperative delirium, early alert and preventions should be taken in advance to reduce the onset of postoperative delirium.