DELIRIUM IN HOSPITALIZED OLDER PERSONS - OUTCOMES AND PREDICTORS

OBJECTIVE: The purpose of this study was fourfold: to determine the ra te of delirium among hospitalized older persons, to contrast the clini cal outcomes of patients with and without delirium, to identify clinic al predictors of delirium, and to validate the predictive model in an independent sample of patients. DESIGN: Two prospective cohort studies SETTING: Medical and surgical wards of 2 university teaching hospital s PATIENTS: In the derivation cohort, 432 patients were enrolled from the University of Chicago Hospitals. Patients 65 years of age or older admitted to 1 of 4 wards were eligible. Subjects were excluded if the y were discharged within 48 hours of admission, unavailable to the res earch assistants during the first 2 days of hospitalization, or judged too impaired to participate in the daily interviews. In the test coho rt, 323 patients 70 years of age or older admitted to Yale-New Haven H ospital were studied. MEASUREMENTS: Subjects were screened for deliriu m daily and referred to experienced clinician investigators if acute m ental status changes were observed. The clinician investigators assess ed the patient for delirium based on DSM III-R criteria. Duration of h ospitalization was adjusted for diagnosis-related groups (DRG) and mor tality rates were determined at discharge and 90 days after discharge. Sociodemographic characteristics, cognitive and functional status, co morbidity, depression, and alcoholism were examined as predictors of d elirium.MAIN RESULTS: The rate of delirium in the derivation cohort wa s 15%; subjects with delirium had longer hospital stays and an increas ed risk of in-hospital death. Cognitive impairment, burden of comorbid ity, depression, and alcoholism were feud to be independent predictors of delirium. The ability of the model to stratify patients as low, mo derate, or high risk for developing delirium was validated in the test cohort in which the rate of delirium was 26%. CONCLUSIONS: This study confirms the high rate of delirium among hospitalized older persons a nd the associated adverse outcomes of prolonged hospital stays and inc reased risk of death. Patients can be stratified according to their ri sk for developing delirium using relatively few clinical characteristi cs which should be assessed, on all hospitalized older persons.