Serial Ottawa 3DY assessments to detect delirium in older emergency department community dwellers

Background: delirium is associated with increased morbidity and mortality among older emergency department (ED) patients. When using physician gestalt, delirium is missed in the majority of patients. The Ottawa 3DY (O3DY) has been validated to detect cognitive dysfunction among older ED patients. Objectives: to determine the sensitivity and specificity of serial O3DY assessments to detect delirium in older ED patients. Design: a prospective observational multicenter cohort study. Setting: four Quebec EDs. Participants: independent or semi-independent older patients (age >= 65 years) with an ED stay of at least 8 hours that required hospitalisation. Measurements: eligible patients were evaluated using serial O3DY assessments at least 6 hours apart. The primary outcome was delirium after at least 8 hours in the ED. The reference standard for delirium assessment was the confusion assessment method (CAM). The sensitivity and specificity of the serial O3DY to detect delirium were calculated. Results: we enrolled 301 patients (mean age 77 years, 49.5% male, 3.0% with a history of mild dementia). Thirty patients (10.0%) were CAM positive for delirium. Patients had a median of three O3DY assessments. Serial O3DY evaluations to detect delirium among patients with at least one abnormal O3DY had a sensitivity of 86.7% (95% confidence interval-CI 69.3-96.2%) and a specificity of 44.3% (95%; CI 38.3-50.4%). Conclusion: serial O3DY testing demonstrates good sensitivity as a screening tool to detect delirium among older adult patients with prolonged ED lengths of stay. Emergency physicians should consider the use of the serial O3DY over clinician gestalt to improve delirium detection.