Does delirium contribute to poor hospital outcomes? A three-site epidemiologic study.
OBJECTIVE
To determine the independent contribution of admission delirium to hospital outcomes including mortality, institutionalization, and functional decline.


METHODS
Three prospective cohort studies.


METHODS
Three university-affiliated teaching hospitals.


METHODS
Consecutive samples of 727 patients, aged 65 years and older.


RESULTS
Delirium was present at admission in 88 (12%) of 727 patients. The main outcome measures at hospital discharge and 3-month follow-up were death, new nursing home placement, death or new nursing home placement, and functional decline. At hospital discharge, new nursing home placement occurred in 60 (9%) of 692 patients, and the adjusted odds ratio (OR) for delirium, controlling for baseline covariates of age, gender, dementia, APACHE II score, and functional measures, was 3.0, (95% confidence interval [CI] 1.4, 6.2). Death or new nursing home placement occurred in 95 (13%) of 727 patients (adjusted OR for delirium 2.1, 95% CI 1.1, 4.0). The findings were replicated across all sites. The associations between delirium and death alone (in 35 [5%] of 727 patients) and between delirium and length of stay were not statistically significant. At 3-month follow-up, new nursing home placement occurred in 77 (13%) of 600 patients (adjusted OR for delirium 3.0; 95% CI 1.5, 6.0). Death or new nursing home placement occurred in 165 (25%) of 663 patients (adjusted OR for delirium 2.6; 95% CI 1.4, 4.5). The findings were replicated across all sites. For death alone (in 98 [14%] of 680 patients), the adjusted OR for delirium was 1.6 (95% CI 0.8, 3.2). Delirium was a significant predictor of functional decline at both hospital discharge (adjusted OR 3.0; 95% CI 1.6, 5.8) and follow-up (adjusted OR 2.7; 95% CI 1.4, 5.2).


CONCLUSIONS
Delirium is an important independent prognostic determinant of hospital outcomes including new nursing home placement, death or new nursing home placement, and functional decline-even after controlling for age, gender, dementia, illness severity, and functional status. Thus, delirium should be considered as a prognostic variable in case-mix adjustment systems and in studies examining hospital outcomes in older persons.
Inouye
S K
SK
Department of Internal Medicine, Yale University School of Medicine, New Haven, Conn 06504, USA.
Rushing
J T
JT
Foreman
M D
MD
Palmer
R M
RM
Pompei
P
P
D000203:Activities of Daily Living; D000368:Aged; D003693:Delirium; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D008297:Male; D011379:Prognosis; D011446:Prospective Studies