Carrasco et al developed an index for identifying an older adult in the hospital who is at risk for delirium. This can help to identify a patient who may benefit from closer monitoring and preventive measures. The authors are from Pontificia Universidad Catolica de Chile.


Patient selection: hospital inpatient >= 65 years of age



(1) blood urea in mmol/L or blood urea nitrogen in mg/dL

(2) serum creatinine in µmol/L or mg/dL

(3) Barthel index (from 0 to 100)


DPS using SI units =

= (1370 * (UN in mmol/L) / (creatinine in µmol/L)) – (4 * (Barthel index))


DPS using US conventional units =

= (5 * (BUN in mg/dL) / (creatinine in mg/dL)) – (3 * (Barthel index))



• The cutoff for the SI unit formula was > -240.

• The cutoff for the US conventional unit formula was > -160.

• A value above the cutoff was associated with increased risk of delirium.

• The cutoff is reached with a normal BUN when the Barthel index is 90. A BUN greater than 33 mg/dL is another trigger.



• The area under the ROC curve was 0.86 in the derivation cohort and 0.78 in the validation cohort.


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