Development and feasibility of a smartphone-based test for the objective detection and monitoring of attention impairments in delirium in the ICU.

PURPOSE: Delirium in the ICU is under-diagnosed. We evaluated feasibility and performance of a novel smartphone-based test for objectively detecting inattention in delirium. MATERIAL AND METHODS: DelApp-ICU combines a behavioural assessment and an attention task, whereby participants follow simple commands and count serially presented circles (score range 0-12, lower scores indicating worse performance). We assessed feasibility through staff interviews. Then we performed a preliminary case-control study in patients with and without delirium (ascertained with the Confusion Assessment Method for the ICU) who underwent the DelApp-ICU on up to 4 days. RESULTS: Forty-six patients (median age = 57.5 years, range 18-83) were assessed 89 times in total (N's = 46, 29, 10 and 4 for subsequent assessments; 33.7% delirious). DelApp-ICU scores were lower in delirium (N = 20; median = 0.5, Inter-Quartile Range (IQR) = 0-4.75) compared to no delirium (N = 26, median = 12, IQR = 8-12) on days 1, 2 and 3 (p < 0.001, p < 0.001 and p < 0.05, respectively). A DelApp-ICU score ≤6 was 100% sensitive and 96% specific to delirium on day 1. Positive and Negative Predictive Values were 91% and 100%, respectively. DelApp-ICU scores were responsive to changes in CAM-ICU status. CONCLUSIONS: DelApp-ICU shows promise for assessing inattention and delirium in ICU patients, including longitudinally monitoring deficits and providing a metric of delirium severity.

A Novel Computerized Test for Detecting and Monitoring Visual Attentional Deficits and Delirium in the ICU.

OBJECTIVES: 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.