Delirium in the ICU is associated with poor outcomes but is under-detected. Here we evaluated performance of a novel, graded test for objectively detecting inattention in delirium, implemented on a custom-built computerized device (Edinburgh Delirium Test Box–ICU).Design:
A pilot study was conducted, followed by a prospective case-control study.Setting:
Royal Infirmary of Edinburgh General ICU.Patients:
A pilot study was conducted in an opportunistic sample of 20 patients. This was followed by a validation study in 30 selected patients with and without delirium (median age, 63 yr; range, 23–84) who were assessed with the Edinburgh Delirium Test Box–ICU on up to 5 separate days. Presence of delirium was assessed using the Confusion Assessment Method for the ICU.Measurements and Main Results:
The Edinburgh Delirium Test Box–ICU involves a behavioral assessment and a computerized test of attention, requiring patients to count slowly presented lights. Thirty patients were assessed a total of 79 times (n = 31, 23, 15, 8, and 2 for subsequent assessments; 38% delirious). Edinburgh Delirium Test Box–ICU scores (range, 0–11) were lower for patients with delirium than those without at the first (median, 0 vs 9.5), second (median, 3.5 vs 9), and third (median, 0 vs 10.5) assessments (all p < 0.001). An Edinburgh Delirium Test Box–ICU score less than or equal to 5 was 100% sensitive and 92% specific to delirium across assessments. Longitudinally, participants’ Edinburgh Delirium Test Box–ICU performance was associated with delirium status.Conclusions:
These findings suggest that the Edinburgh Delirium Test Box–ICU has diagnostic utility in detecting ICU delirium in patients with Richmond Agitation and Sedation Scale Score greater than –3. The Edinburgh Delirium Test Box–ICU has potential additional value in longitudinally tracking attentional deficits because it provides a range of scores and is sensitive to change.