[Development and validation of a clinical predictive model for delirium in hospitalized older people].
BACKGROUND
Delirium is a prevalent problem among older patients and it is frequently underdiagnosed.


OBJECTIVE
To develop and validate a clinical predictive model to identify patients at high risk of delirium.


METHODS
Two consecutive prospective cohort studies were used to develop and validate the model. The development cohort included 542 consecutive medical inpatients, 65 years or older. The validation cohort included 85 comparable patients. A predictive score was constructed with a multivariate analysis, using variables independently associated with delirium and subsequently tested in the new cohort. Patients were assessed within the first 48 hours of admission, and every 48 hours thereafter, using the Confusion Assessment Method to diagnose delirium, evaluating also the severity of underlying disease, comorbidities, functionality, and laboratory data.


RESULTS
Delirium occurred in 192 patients (35.4%) of the development cohort and was independently associated with age and functional status assessed using the Barthel Index. With these two variables, the predictive score for delirium was developed and tested rendering an area under the receiver operating characteristic (ROC) of 0.80 (confidence intervals 0.77-0.85). Cut-off points were chosen to establish low, intermediate, and high-risk groups for delirium. According to these cut-off points, delirium frequencies in the development cohort were 8%, 23%, and 69%, and in the validation cohort 5%, 34%, and 66%, respectively (c² p<0.05).


CONCLUSIONS
This simple predictive model based on age and functional status may be a useful tool for identifying older patients risking delirium.
Marcela
M
Carrasco G
Luis
L
Villarroel D
Jorge
J
Calderón P
Gabriel
G
Martínez F
Maricarmen
M
Andrade A
Matías
M
González T
D000368:Aged; D000369:Aged, 80 and over; D002677:Chile / Q000453:epidemiology; D003693:Delirium / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D015577:Geriatric Assessment / Q000379:methods; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male