The impact of preoperative frailty on perioperative neurocognitive disorders in elderly patients: A systematic review and meta-analysis

Background: Perioperative neurocognitive disorders (PNDs) were the most common complication in elderly patients undergoing surgery. Early identification of risk factors for PNDs and implementation of preventive measures were critical to improve prognosis. We performed this systematic review and meta-analysis to explore the impact of preoperative frailty on PNDs in elderly surgical patients. Materials and Methods: Systematic searches were performed in PubMed, Embase, and Web of Science. A fixed-effect model in RevMan5.3 software was conducted due to the low heterogeneity. The potential risk bias was assessed through Funnel plot and Egger's test. Sensitivity analysis was used to examine the robustness of the outcomes. Results: Sixteen cohort studies enrolling 4805 elderly patients were qualified for meta-analysis. Pooled results showed that preoperative frailty was linked to the development of PNDs (pooled odds ratio [OR]: 2.40, 95% confidence interval [CI]: 2.05-2.80, P < 0.001) without obvious heterogeneity (P = 0.19, I2 = 22%). Subgroup analyses revealed that the correlation between preoperative frailty and PNDs was more remarkable in prospective cohort studies (OR: 3.11, 95% CI: 2.47-3.91, P < 0.001) compared to retrospective cohort studies (OR: 1.94, 95% CI: 1.57-2.39, P < 0.001; test for subgroup difference, P = 0.003). In addition, the correlation in patients with cardiac surgery (OR: 3.38, 95% CI: 2.44-4.68, P < 0.001) was more noticeable than noncardiac surgery (OR: 2.17, 95% CI: 1.82-2.59, P < 0.001; test for subgroup difference P = 0.02). Conclusion: Our results demonstrated that preoperative frailty was independently associated with PNDs in geriatric patients undergoing elective surgery.