Adaptation and Validation of a Chart-Based Delirium Detection Tool for the ICU (CHART-DEL-ICU)

OBJECTIVE To adapt and validate a chart-based delirium detection tool for use in critically ill adults. DESIGN Validation study. SETTING Medical-surgical intensive care unit (ICU) in an academic hospital. MEASUREMENTS A chart-based delirium detection tool (CHART-DEL) was adapted for use in critically ill adults (CHART-DEL-ICU) and compared with prospective delirium assessments (i.e., clinical assessments (reference standard) by a research nurse trained by a neuropsychiatrist and routine delirium screening tools Confusion Assessment Method (CAM-ICU)) and (Intensive Care Delirium Screening Checklist (ICDSC)). The original CHART-DEL tool was adapted to include physician-reported ICDSC score (for probable delirium) and Richmond-Agitation Sedation Scale score (for altered level of consciousness and agitation). Two trained chart abstractors blinded to all delirium assessments manually abstracted delirium-related information from medical charts and electronic medical records and rated if delirium was present (four levels: uncertain, possible, probable, definite) or absent (no evidence). RESULTS Charts were manually abstracted for delirium-related information for 213 patients who were included in a prospective cohort study that included prospective delirium assessments. The CHART-DEL-ICU tool had excellent interrater reliability (kappa = 0.90). Compared to the reference standard, the sensitivity was 66.0% (95% CI = 59.3-72.3%) and specificity was 82.1% (95% CI = 78.0-85.7%), with a cut-point that included definite, probable, possible, and uncertain delirium. The AUC of the CHART-DEL-ICU alone is 74.1% (95% CI = 70.4-77.8%) compared with the addition of the CAM-ICU and ICDSC (CAM-ICU/CHART-DEL-ICU: 80.9% (95% CI = 77.8-83.9%), P = .01; ICDSC/CHART-DEL-ICU: 79.2% (95% CI = 75.9-82.6%), P = .03). CONCLUSION A chart-based delirium detection tool has improved diagnostic accuracy when combined with routine delirium screening tools (CAM-ICU and ICDSC), compared to a chart-based method on its own. This presents a potential for retrospective detection of delirium from medical charts for research or to augment routine delirium screening methods to find missed cases of delirium.

Automated summary

This study validated a chart-based delirium detection tool (CHART-DEL-ICU) for use in critically ill adults, showing excellent interrater reliability and improved diagnostic accuracy when combined with routine delirium screening tools (CAM-ICU and ICDSC).