Impact on delirium detection of using a sensitive instrument integrated into clinical practice

Early symptoms of delirium often go unnoticed. The Nursing Delirium Screening Scale (Nu-DESC) is a recently developed short, accurate and sensitive 24-h screening instrument. The Nu-DESC is more sensitive than the instrument from which it was derived, the Confusion Rating Scale (CRS). This study examined the impact on delirium detection of using the Nu-DESC over the CRS in 134 consecutive oncology patients. Expected false-negative rate (FNR) reductions at different delirium prevalence rates when using the Nu-DESC compared to the CRS and the number needed to screen (NNS) by the Nu-DESC were calculated. Kaplan-Meier survival analyses were used to study Nu-DESC-CRS divergences in delirium status and length of delirium-free survival. Ninety-nine patients were negative for delirium according to both tests. Of the remaining 35 patients, 16 had identical Nu-DESC-CRS delirium status and delirium-free survival, whereas 19 were detected later by the CRS (mean, 4.8 days). Among the 19 patients, 6 were still CRS negative upon hospital discharge. Integrating a continuous and sensitive delirium assessment instrument into usual care can facilitate its recognition, since more cases of delirium are diagnosed and patients are detected earlier. (c) 2005 Elsevier Inc. All rights reserved.