Validation of a Nurse-Based Delirium Screening Tool for Hospitalized Patients

Background Guidelines recommend daily delirium monitoring of hospitalized patients. Available delirium-screening tools have not been validated for use by nurses among diverse inpatients. We sought to validate the Nursing Delirium Screening Scale (Nu-DESC) under these circumstances. Design Blinded cross-sectional and quality improvement study conducted August 2015-February 2016. Nurses′ Nu-DESC scores were compared to delirium diagnosis according to Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) criteria. Participants 405 consecutive hospitalized patients were included. Nu-DESC positive (threshold score ≥2) patients were matched with equal numbers of Nu-DESC negative patients, by sex, age and nursing unit. Measurements Nurses recorded a Nu-DESC score for each patient on every 12-hour shift. A Nu-DESC-blinded evaluator interviewed patients for two consecutive days. Delirium diagnosis was determined by physicians using DSM-5 criteria applied to collected research data. Sensitivity and specificity of the Nu-DESC were calculated. In an exploratory analysis, the performance of the Nu-DESC was analyzed with the addition of bedside measures of attention. Results The sensitivity of the Nu-DESC at a threshold of ≥ 2 was 42% (95% confidence interval, 33–53%). Specificity was 98% (97–98%). At a threshold of ≥ 1, sensitivity was 67% (52–80%) and specificity 93% (90–95%). Similar results were found with the addition of attention tasks. Conclusion The Nu-DESC is a specific delirium detection tool but it is not sensitive at the usually proposed cut point of ≥ 2. Using a threshold of ≥ 1 or adding a test of attention increase sensitivity with a minor decrease in specificity.