Postoperative delirium and functional decline after noncardiac surgery.

Objectives: To determine whether delirium after noncardiac surgery is associated with functional decline 3 months postoperatively.

Design: Secondary analysis of a prospective study.

Setting: Thirteen hospitals in eight countries.

Participants: One thousand two hundred eighteen individuals aged 60 and older undergoing noncardiac surgery.

Measurements: Participants were interviewed before surgery and 3 months postoperatively using six items pertaining to social and independent function. Functional decline was determined according to a loss in function in at least one item at the 3-month assessment from baseline. Postoperatively, a trained interviewer assessed delirium daily using a standardized battery. The primary outcome of this analysis was an examination of the risk of functional decline with delirium.

Results: Of the 948 participants who completed functional assessment at 3 months, 20% (n = 189) had a decline in function. In unadjusted analysis, postoperative delirium increased the odds of functional decline (odds ratio (OR) = 2.4, 95% confidence interval (CI) = 1.4-4.2). After adjustment for age, sex, education, cognition, and surgery duration, delirium remained associated with functional decline (OR = 2.1, 95% CI = 1.2-3.8).

Conclusion: Although considered an acute event, delirium can have lasting functional consequences. Clinicians should give strong consideration to preoperative delirium risk assessment, delirium prevention strategies, and delirium surveillance programs after noncardiac surgery.