Delirium: an independent predictor of functional decline after cardiac surgery

J Am Geriatr Soc. 2010 Apr;58(4):643-9. doi: 10.1111/j.1532-5415.2010.02762.x. Epub 2010 Mar 22.


Objectives: To determine whether patients who developed delirium after cardiac surgery were at risk of functional decline.

Design: Prospective cohort study.

Setting: Two academic hospitals and a Veterans Affairs Medical Center.

Participants: One hundred ninety patients aged 60 and older undergoing elective or urgent cardiac surgery.

Measurements: Delirium was assessed daily and was diagnosed according to the Confusion Assessment Method. Before surgery and 1 and 12 months postoperatively, patients were assessed for function using the instrumental activities of daily living (IADL) scale. Functional decline was defined as a decrease in ability to perform one IADL at follow-up.

Results: Delirium occurred in 43.1% (n=82) of the patients (mean age 73.7+/-6.7). Functional decline occurred in 36.3% (n=65/179) at 1 month and in 14.6% (n=26/178) at 12 months. Delirium was associated with greater risk of functional decline at 1 month (relative risk (RR)=1.9, 95% confidence interval (CI)=1.3-2.8) and tended toward greater risk at 12 months (RR=1.9, 95% CI=0.9-3.8). After adjustment for age, cognition, comorbidity, and baseline function, delirium remained significantly associated with functional decline at 1 month (adjusted RR=1.8, 95% CI=1.2-2.6) but not at 12 months (adjusted RR=1.5, 95% CI=0.6-3.3).

Conclusion: Delirium was independently associated with functional decline at 1 month and had a trend toward association at 12 months. These findings provide justification for intervention trials to evaluate whether delirium prevention or treatment strategies might improve postoperative functional recovery.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Academic Medical Centers
  • Activities of Daily Living
  • Aged
  • Cardiac Surgical Procedures / adverse effects*
  • Cardiac Surgical Procedures / rehabilitation
  • Chi-Square Distribution
  • Delirium / diagnosis
  • Delirium / epidemiology
  • Delirium / etiology*
  • Female
  • Geriatric Assessment
  • Hospitals, Veterans
  • Humans
  • Linear Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Predictive Value of Tests
  • Prospective Studies
  • Recovery of Function*
  • Risk Assessment
  • Severity of Illness Index
  • Statistics, Nonparametric
  • Time Factors