Exploring the Relationship Between Neighborhood Disadvantage and ICU Delirium Characteristics

Abstract

Importance: Delirium is a neuropsychiatric syndrome characterized by fluctuating disturbances in attention and awareness, associated with worse clinical outcomes and higher mortality. Previous research studies have noted an association between geographic disadvantage and delirium, but it is unknown if this association extends to critically ill adults. Objectives: This study aimed to explore the relationship between geographic disadvantage and ICU delirium characteristics. Design, setting, and participants: We performed a secondary analysis of data collected from an National Institutes of Health-funded clinical trial, the Pharmacologic Management of Delirium study. Adults 18 years old or older admitted to the ICU who experienced delirium based on the Confusion Assessment Method for the ICU (CAM-ICU) were included. Interventions: None. Measurements and main results: The study population included 326 participants: 54.5% were female and 48% Black, with a mean age of 60.3 years, mean Acute Physiology and Chronic Health Evaluation II score of 20, and in-hospital mortality rate of 12.3%. The area deprivation index (ADI), a composite measure of geographic disadvantage derived from census data that yields a national percentile score ranging from 1 to 100 (with higher scores representing greater disadvantage), was obtained for each participant's address. Main outcome variables included delirium duration, which was assessed by the number of delirium- and coma-free days (DCFDs), and delirium severity, which was assessed by mean CAM-ICU-7 scores. Analysis of covariance models were used to examine differences in DCFDs and mean CAM-ICU-7 scores between ADI quintiles while controlling for demographic and clinical variables. Other clinical outcomes of interest included discharge home rates and in-hospital mortality. The sample was heavily skewed toward higher national ADI percentile scores (indicating greater disadvantage); only 11.7% of patients had an ADI score lower than 50. Our regression analyses did not reveal any associations between ADI quintile and DCFDs or mean CAM-ICU-7 scores, or between ADI quintile and discharge home rates or in-hospital mortality. However, the Black race was associated with longer delirium duration and greater delirium severity in the first week of ICU hospitalization. Conclusions: Our study did not find an association between geographic disadvantage and delirium duration or severity in the ICU. However, an association with race was observed, highlighting the need for further research into how socioeconomic determinants of health relate to delirium.