Association Between Preoperative Cognitive Performance and Postoperative Delirium in Older Patients: Results From a Multicenter, Prospective Cohort Study, and a Mendelian Randomization Study.

This study evaluated the association between preoperative cognitive performance and postoperative delirium (POD) using a multicenter prospective cohort, and explored potential causality using Mendelian randomization (MR) analysis. We analyzed data from 2257 patients aged ≥ 75 years undergoing elective noncardiac and noncranial surgeries across 16 Chinese medical centers. Preoperative cognitive assessment using Mini-Cog revealed 28.4% of patients had cognitive impairment (score ≤ 2). POD occurred in 9.7% of patients, with higher incidence among those with cognitive impairment. Logistic regression demonstrated that cognitive impairment was significantly associated with increased POD risk (odds ratio [OR], 2.06; 95% confidence interval [CI], 1.55-2.74; p < 0.001). This association persisted after adjustment for demographic, preoperative, and intraoperative factors, and was confirmed through propensity score matching and inverse probability treatment weighting analyses. A nearly linear inverse association was observed between Mini-Cog scores and POD incidence. Complementary MR analysis using 139 SNPs from European ancestry data suggested that higher cognitive performance might be associated with decreased delirium risk (inverse-variance weighted OR, 0.74; 95% CI, 0.59-0.93; p = 0.009). Although these results point to a potential link between preoperative cognition and POD, interpretation of causality should be approached with caution, particularly given differences in populations and genetic datasets.