- Postoperative delirium (POD) is common in older surgical patients and is associated with adverse long-term outcomes, including functional impairment, dementia, and cognitive decline.
- Whether this association represents causation versus correlation remains an open question: it is unclear whether the development of POD itself leads to cognitive decline, or whether it is merely a marker of more frail patients, with more comorbidities, who were already more likely to develop these adverse long-term neurocognitive outcomes.
- To address this question, this prospective observational cohort study analyzed data from the Successful Aging after Elective Surgery (SAGES) cohort, which included 560 adults aged 70 years or older undergoing major elective surgery, with longitudinal follow-up for up to 6 years.
- Cognitive decline in this cohort was measured by change in General Cognitive Performance (GCP) score, a compositive measure of 11 neuropsychological tests that were administered as a preoperative baseline and then repeated 10 times over 5 years.
- The authors found that patients who developed POD experienced a more rapid long-term cognitive decline when compared with patients without delirium, a difference of 0.33 GCP units per year.
- In addition, patients who developed POD experienced more frequent rehospitalizations during follow-up (adjusted incidence rate ratio 1.42).
- Somewhat surprisingly, however, the authors found that rehospitalization does not mediate the association between POD and long-term cognitive decline, as adjustment for combined rehospitalizations and for each type of rehospitalization resulted only in a minimal, non-statistically significant change in the association of delirium with cognitive decline.
- The authors therefore concluded that POD represents the strongest risk factor for persistent cognitive decline in older patients undergoing surgery, and that further work is warranted to better understand this process.
- This study highlights the importance of delirium prevention, early recognition, and continued postoperative follow-up in older surgical patients.
Summary of "Rehospitalization and the Association of Postoperative Delirium With Cognitive Decline in Older Adults"
Summary published September 21, 2026
