Confirmatory Factor Analysis of the Delirium Rating Scale Revised-98 (DRS-R98)

Abstract

Principal components analysis applied to the Delirium Rating Scale-Revised-98 contributes to understanding the delirium construct. Using a multisite pooled international delirium database, the authors applied confirmatory factor analysis to Delirium Rating Scale-Revised-98 scores from 859 adult patients evaluated by delirium experts (delirium, N=516; nondelirium, N=343). Confirmatory factor analysis found all diagnostic features and core symptoms (cognitive, language, thought process, sleep-wake cycle, motor retardation), except motor agitation, loaded onto factor 1. Motor agitation loaded onto factor 2 with noncore symptoms (delusions, affective lability, and perceptual disturbances). Factor 1 loading supports delirium as a single construct, but when accompanied by psychosis, motor agitation's role may not be solely as a circadian activity indicator.

Distinguishing characteristics of delirium in a skilled nursing facility in Spain: Influence of baseline cognitive status

“…Clinicians are warned not to rely on them for delirium detection and, combined with their less frequent occurrence, will result in underdiagnosis. 15,16,30,32 Interestingly, DRS-R98 diagnostic items assessing temporal onset and course and symptom fluctuation did not increase discriminant accuracy for delirium in the logistic model, except in those without MCI-DEM. In other words, when MCI-DEM is present, it is difficult to discern the very moment when delirium starts, which can be subacute and mild, and where fluctuation of symptoms is hard to verify when cognitive status already includes some degree of impairment at baseline.…”

“…6 This contrasts with best practices taught in general hospitals where cognitive deficits are assumed to be delirium until proven otherwise. 16 In contrast, memory deficits are cardinal in many DEMs, with varying occurrence of aphasia, apraxia, agnosia, or dysexecutive function, while attention is relatively preserved. 7,8 Compounding this is the overlap in delirium and DEM symptoms making differential diagnosis challenging, even though it is well established that delirium symptoms overshadow those of DEM when comorbid.…”

“…Temporal course of symptoms distinguishes delirium from DEM where acute/subacute onset presents as a "worsening" in DEM patients and has a fluctuating course. 16 In contrast, memory deficits are cardinal in many DEMs, with varying occurrence of aphasia, apraxia, agnosia, or dysexecutive function, while attention is relatively preserved. Research shows that simple inattention on digit span forward is more pronounced in delirium than DEM and distinguishes them.…”

“…All symptoms are measured with the DRS-R98. Clinicians are warned not to rely on them for delirium detection and, combined with their less frequent occurrence, will result in underdiagnosis 15,16,30,32. .…”

Instrumentos para el diagnóstico de delirium en hispanohablantes: artículo de revisión

“…Evalúa tanto el grado de alerta como varias características cognitivas (orientación, memoria a corto plazo, span de dígitos y atención), también el curso del pensamiento, la actividad motora (en un solo ítem para todas las alteraciones), el ciclo sueño vigilia y la psicosis (síntoma accesorio). Está compuesta por dos factores, uno neurocomportamental, en el que se incluyen las alteraciones del ritmo circardiano, y otro neurocognitivo, que llegan a concordar desde el punto de vista teórico con la fenomenología del delirium descrita por el grupo de trabajo de Trzepacz 11,[54][55][56][57] , aunque fue pensada para evaluar la gravedad del síndrome (se correlaciona muy bien con la Delirium Rating Scale o DRS), también tiene utilidad diagnóstica (en el estudio de validación original diferenció el delirium de otros trastornos neurocognitivos o de pacientes sin alteración del estado mental). Hay una versión para hispanohablantes obtenida a partir de la traducción del instrumento original, que se validó en España con pacientes oncológicos y mostró confiabilidad y validez similares a la escala original 58 .…”