RESUMO
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 4â¯days. RESULTS: Forty-six patients (median ageâ¯=â¯57.5â¯years, range 18-83) were assessed 89 times in total (N'sâ¯=â¯46, 29, 10 and 4 for subsequent assessments; 33.7% delirious). DelApp-ICU scores were lower in delirium (Nâ¯=â¯20; medianâ¯=â¯0.5, Inter-Quartile Range (IQR)â¯=â¯0-4.75) compared to no delirium (Nâ¯=â¯26, medianâ¯=â¯12, IQRâ¯=â¯8-12) on days 1, 2 and 3 (pâ¯<â¯0.001, pâ¯<â¯0.001 and pâ¯<â¯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.