Medical and economic burden of delirium on hospitalization outcomes of acute respiratory failure: A retrospective national cohort.

Although delirium in patients with acute respiratory failure (ARF) may evolve in any hospital setting, previous studies on the impact of delirium on ARF were restricted to those in the intensive care unit (ICU). The data about the impact of delirium on ARF hospitalizations outside of the ICU is limited. Therefore, we conducted the first national study to examine the effect-magnitude of delirium on ARF in all hospital settings, that is, in the ICU as well as on the general medical floor. We searched the 2016 and 2017 National Inpatient Sample databases for ARF hospitalizations and created "Delirium" and "No delirium" groups. The outcomes of interest were mortality, endotracheal intubation, length of stay (LOS), and hospitalization costs. We also aimed to explore any potential demographic, racial, or healthcare disparities that may be associated with the diagnosis of delirium among ARF patients. Multivariable logistic regression was used to control for demographics and comorbidities. Delirium was present in 12.7% of the sample. Racial disparities among African Americans were also significant. Delirious patients had more comorbidities, higher mortality, and intubation rates (17.5% and 9.2% vs 10.6% and 6.1% in the "No delirium" group [P < .001], respectively). Delirious patients had a longer LOS and higher hospitalization costs (5.9 days and $15,395 USD vs 3.7 days and $9393 USD in "No delirium" [P < .001], respectively). Delirium was associated with worse mortality (adjusted odds ratio 1.49, confidence interval [CI] = 1.41, 1.57), higher intubation rates (adjusted odds ratio 1.46, CI = 1.36, 1.56), prolonged LOS (adjusted mean ratio 1.40, CI = 1.37, 1.42), and increased hospitalization costs (adjusted mean ratio 1.49, CI = 1.46, 1.52). A racial disparity in the diagnosis of delirium among African Americans hospitalized with ARF was noted in our sample. Patients in small, non-teaching hospitals were diagnosed with delirium less frequently compared to large, urban, teaching centers. Delirium predicts worse mortality and morbidity for ARF patients, regardless of bed placement and severity of the respiratory failure.