Prediction of Long-term Cognitive Decline Following Postoperative Delirium in Older Adults.
BACKGROUND
Increasing evidence suggests that postoperative delirium may result in long-term cognitive decline among older adults. Risk factors for such cognitive decline are unknown.


METHODS
We studied 126 older participants without delirium or dementia upon entering the Successful AGing After Elective Surgery (SAGES) study, who developed postoperative delirium and completed repeated cognitive assessments (up to 36 months of follow-up). Pre-surgical factors were assessed preoperatively and divided into nine groupings of related factors ("domains"). Delirium was evaluated at baseline and daily during hospitalization using the Confusion Assessment Method diagnostic algorithm, and cognitive function was assessed using a neuropsychological battery and the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) at baseline and 6-month intervals over 3 years. Linear regression was used to examine associations between potential risk factors and rate of long-term cognitive decline over time. A domain-specific and then overall selection method based on adjusted R2 values was used to identify explanatory factors for the outcome.


RESULTS
The General Cognitive Performance (GCP) score (combining all neuropsychological test scores), IQCODE score, and living alone were significantly associated with long-term cognitive decline. GCP score explained the most variation in rate of cognitive decline (13%), and six additional factors-IQCODE score, cognitive independent activities of daily living impairment, living alone, cerebrovascular disease, Charlson comorbidity index score, and exhaustion level-in combination explained 32% of variation in this outcome.


CONCLUSIONS
Global cognitive performance was most strongly associated with long-term cognitive decline following delirium. Pre-surgical factors may substantially predict this outcome.
Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
Elizabeth E
EE
Devore
Aging Brain Center, Institute of Aging Research, Hebrew SeniorLife, Boston, Massachusetts.|Department of Neurology.
Tamara G
TG
Fong
Aging Brain Center, Institute of Aging Research, Hebrew SeniorLife, Boston, Massachusetts.|Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.
Edward R
ER
Marcantonio
Aging Brain Center, Institute of Aging Research, Hebrew SeniorLife, Boston, Massachusetts.
Eva M
EM
Schmitt
Aging Brain Center, Institute of Aging Research, Hebrew SeniorLife, Boston, Massachusetts.|Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.
Thomas G
TG
Travison
Aging Brain Center, Institute of Aging Research, Hebrew SeniorLife, Boston, Massachusetts.|Departments of Psychiatry and Human Behavior and Neurology, Brown University Warren Alpert Medical School, Providence, Rhode Island.
Richard N
RN
Jones
Aging Brain Center, Institute of Aging Research, Hebrew SeniorLife, Boston, Massachusetts.|Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.
Sharon K
SK
Inouye
D000368:Aged; D060825:Cognitive Dysfunction / Q000209:etiology*; D003693:Delirium / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D011183:Postoperative Complications; D011379:Prognosis; D000075082:Proof of Concept Study; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors
Cognition; Delirium; Elective surgery; Risk factors