Delirium Assessment Tools for Use in Critically Ill Adults: A Psychometric Analysis and Systematic Review

BACKGROUND Delirium is highly prevalent in critically ill patients. Its detection with valid tools is crucial. OBJECTIVE To analyze the development and psychometric properties of delirium assessment tools for critically ill adults. METHODS Databases were searched to identify relevant studies. Inclusion criteria were English language, publication before January 2015, 30 or more patients, and patient population of critically ill adults (>18 years old). Search terms were delirium, scales, critically ill patients, adult, validity, and reliability. Thirty-six manuscripts were identified, encompassing 5 delirium assessment tools (Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), Cognitive Test for Delirium, Delirium Detection Score, Intensive Care Delirium Screening Checklist (ICDSC), and Nursing Delirium Screening Scale). Two independent reviewers analyzed the psychometric properties of these tools by using a standardized scoring system (range, 0-20) to assess the tool development process, reliability, validity, feasibility, and implementation of each tool. RESULTS Psychometric properties were very good for the CAM-ICU (19.6) and the ICDSC (19.2), moderate for the Nursing Delirium Screening Scale (13.6), low for the Delirium Detection Score (11.2), and very low for the Cognitive Test for Delirium (8.2). CONCLUSIONS The results indicate that the CAM-ICU and the ICDSC are the most valid and reliable delirium assessment tools for critically ill adults. Additional studies are needed to further validate these tools in critically ill patients with neurological disorders and those at various levels of sedation or consciousness.