Postoperative Delirium Associated With Substantial Risk

Delirium following major non-cardiac surgery is associated with higher risk for death and other major complications, according to findings published in JAMA Network Open.

Researchers conducted a retrospective cohort study of patients 65 years of age and older who underwent non-cardiac surgery in US hospitals between 2017 and 2020 to evaluate the association between postoperative delirium and 30-day mortality. They also examined hospital-level variation in postoperative delirium. The primary outcome was composite of death and major complications, and secondary outcomes included 30-day mortality and non-home discharge. Multilevel logistic regression models were employed for statistical analysis.

The study included 5,530,054 patients from 3169 hospitals, of whom the mean (SD) age was 74.7 (7.0) years, 57.2% were women, and 82.6% were White. Postoperative delirium was documented in 3.6% of admissions. Those who experience postoperative delirium were slightly older than those who did not (mean [SD] age, 78.3 [8.0] vs 74.5 [6.9] years), more likely to be men (46.1% vs 42.7%), less likely to be electively admitted (43.9% vs 72.9%), and less likely to be admitted from the community (90.0% vs 96.4%).

Comorbidities were also more prevalent among those with vs without postoperative delirium, including malnutrition (17.7% vs 4.3%), cerebrovascular disease (5.4% vs 2.6%), heart failure (20.9% vs 8.2%), paralysis (4.4% vs 1.8%), and dementia (17.5% vs 4.3%).

Unadjusted incidence of death or major complications was 19.5% in patients with postoperative delirium vs 2.9% in those without (odds ratio [OR], 5.50; 95% CI, 5.40-5.60; P <.001). After adjustment, postoperative delirium was still associated with increased likelihood of death or major complications (adjusted OR [aOR], 3.47; 95% CI, 3.41-3.53; P <.001), 30-day mortality (aOR, 2.77; 95% CI, 2.71-2.83; P <.001), and nonhome discharge (aOR, 3.96; 95%CI, 3.88-4.04; P <.001). Results remained consistent after adjusting for hospital characteristics and excluding early COVID-19 admissions.

Median hospital rate of postoperative delirium was 3.02% (IQR, 1.54-4.65), and significant variation was observed between hospitals. Patients with similar characteristics had a 1.5 times higher risk for postoperative delirium at higher-incidence hospitals.

Study limitations include underreported Medicare claims.

“The wide variation across hospitals and its association with increased risks of mortality, major complications, and nonhome discharge underscores the need for targeted interventions aimed at improving perioperative brain health,” the authors concluded.

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.