Fritz BA, King CR, Ben Abdallah A, et al. - Given postoperative delirium acts as a barrier to recovery post-surgery, and a link of intraoperative electroencephalogram suppression with postoperative delirium has been shown, however, whether this link is causal or if electroencephalogram suppression is only a marker of underlying cognitive abnormalities is yet to be known, so researchers undertook this prespecified secondary analysis of the Electroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes (ENGAGES) randomized trial, to investigate whether intraoperative electroencephalogram suppression mediates a nonzero portion of the impact between preoperative abnormal cognition and postoperative delirium. Participants were patients age 60 yr or older undergoing surgery with general anesthesia. The patients were randomly assigned to electroencephalogram-guided anesthesia or usual care. Findings revealed that electroencephalogram suppression mediated a small portion of the total impact of preoperative abnormal cognition on postoperative delirium. If the mediated effect was altered by the intervention was a question that remained unanswered due to too low study precision.