Validation of the Intensive Care Delirium Screening Checklist in nonintubated intensive care unit patients in a resource-poor medical intensive care setting in South India

Objective: Delirium is a common, difficult-to-diagnose clinical condition in critical care units. The lack of recognition of delirium often results in increased morbidity and mortality. The study aimed to determine the validity and reliability of the Intensive Care Delirium Screening Checklist (ICDSC) in a resource-poor medical intensive care setting in South India. Materials and methods: Fifty-three patients admitted into the medical intensive care unit of a teaching hospital who were neither mute nor intubated were recruited for the study. Trained residents administered the ICDSC to screen for delirium. A consultant psychiatrist used the International Classification of Diseases, 10th Revision diagnostic criteria for research to determine the presence of delirium. Results: The optimal threshold for screening, as ICDSC total score of 3 or more, was obtained by using a receiver operating characteristic curve. Although a sensitivity and specificity of 75% and 74%, respectively, were obtained at the original cutoff of 4, a sensitivity of 90% and specificity of 61.54% were achieved with a cutoff of 3. In a subsample of 21 patients, interrater reliability was evaluated and found to be 0.947 (95% confidence interval, 0.870-0.979). The ICDSC had good internal consistency, with Cronbach alpha of .754 and Guttman split-half coefficient of 0.71. Factor analysis revealed a 2-factor structure, namely, altered sensorium/psychopathology and sleep-wake cycle problems. Conclusions: Our findings indicate that in nonintubated intensive care unit patients, the ICDSC can be used to screen for delirium but should not be used as a diagnostic instrument in this patient population and that residents can be trained in the use of the instrument in resource-poor critical care settings. Using a different threshold for positivity of 3 rather than 4 appeared to offer improved screening characteristics in this resource-poor critical care setting. (C) 2011 Elsevier Inc. All rights reserved.