Abstract: Objective To explore the predictive value of subjective cognitive decline (SCD) on postoperative delirium (POD). Methods A total of 156 elderly patients scheduled for non-cardiac surgeries were selected. The development of SCD was assessed by Subjective Cognitive Decline Questionnaire(SCD-Q9 )one day before surgery. Peripheral venous blood samples were collected to detect the levels of serum biomarkers before anesthesia induction. The patients received POD assessment using Chinese version of Confusion Assessment Method 1-3 d after operation. Then the patients were divided into the POD group and the non-POD group. Multiple Logistic regression analysis was used to analyze the risk factors for POD. The receiver operating characteristic curve(ROC) was drawn and the area under the curve (AUC) was calculated to evaluate the predictive value of SCD on POD. Results Compared with the non-POD group, the incidence of SCD, serum levels of interleukin-6 (IL-6) and neurofilament light were significantly increased in the POD group (P<0.05). Logistic regression analysis showed that SCD (OR=1.952,95% CI:1.183-3.532,P < 0.05) and preoperative serum IL-6 (OR=1.103, 95% CI:1.052-1.154,P<0.05) were the risk factors for the development of POD. Preoperative SCD and serum IL-6 showed an AUC of 0.768 (95% CI:0.692-0.845,P<0.001) and 0.865 (95% CI:0.784-0.945,P＜0.001) to predict POD respectively. Conclusions Preoperative SCD is a significant risk factor for POD, which could be used to predict the incidence of POD.

Key words: cognitive function, surgery, aged, delirium, risk factors