Brief report: preoperative frailty in older surgical patients is associated with early postoperative delirium.

We investigated whether preoperative frailty among older noncardiac surgical patients provides information about the development of postoperative delirium that is in addition to traditional geriatric risk factors. One-third of patients had a frailty score ≥3, which is considered "frail" in others' research. Twenty-five percent of patients developed postoperative delirium, which was measured using the confusion assessment method. Multivariable logistic regression showed that age, activities of daily living dependence, instrumental activities of daily living dependence, and cognitive functioning did not contribute significantly to the prediction of postoperative delirium. Only preoperative symptoms of depression (odds ratio=1.42; 95% confidence interval=1.06-1.91; P=0.018) and the frailty score (odds ratio=1.84; 95% confidence interval=1.07-3.1; P=0.028) were independently associated with the development of postoperative delirium.