Diagnostic accuracy of delirium assessment methods in critical care patients

Abstract

Purpose: Delirium is a disorder of decreased ability to focus, sustain or shift attention, change in cognition and or perception. The main objective was to evaluate the diagnostic accuracy of Confusion Assessment Method for the ICU (CAM-ICU) and Intensive Care Delirium Screening Checklist (ICDSC) among the nursing and medical staff in a multidisciplinary ICU.

Methods and material: Three hundred ten verbally communicating and non-communicating patients (mean age in years 47.9, standard deviation [SD] 14.5, mean Acute Physiology and Chronic Health Evaluation II score 13.8, SD 6.4) were assessed by a psychiatrist, nurse and intensivist for delirium. Inter-rater agreement was measured by Cohen's kappa coefficient. Sensitivity, specificity, predictive values, likelihood ratios and diagnostic odds ratio (DOR) were calculated.

Results: CAM-ICU showed higher sensitivity and DOR (84%, 86.1) compared to ICDSC (78%, 36.9). ICDSC had specificity and positive predictive value (94.5%, 92%) equal to that of CAM-ICU. For both the assessment methods (CAM-ICU and ICDSC), DORs for intensivists (120.5, 53.0) were relatively higher than nurses (67.0, 27.0).

Conclusions: In our mixed ICU population, CAM-ICU remained more sensitive than ICDSC. Though sensitivity and DOR were higher for medical staff, other diagnostic parameters were similar for both medical and nursing staff.

Keywords: Assessment; Delirium; Intensive care unit; Sensitivity; Specificity.