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.