Postoperative cognitive impairment has been challenging to define given the varied cognitive tests used across previous studies. Also, earlier literature is unclear whether exposure to an operation, often using ill-defined surgical and anesthesia factors without nonoperative controls, played an independent role in long-term cognition. However, the momentum of current evidence is that preoperative patient features (eg, educational level, employment) and critical neurologic events during hospitalization (eg, delirium) independently influence long-term cognition. Operation alone does not appear to influence long-term cognition.1-4 So, we read with great interest this work by Austin et al,5 published in this issue of JAMA Surgery, that evaluated 191 patients after nonemergent surgery across multiple specialties and concluded that those with preoperative cognitive impairment have improved cognition 90 days postoperatively and that this nonsignificant outcome was attenuated by delirium.