Effect of Delirium on Interhospital Transfer Outcomes.

Objectives: Interhospital transfer (IHT) and in-hospital delirium are both independently associated with increased length of stay (LOS), mortality, and discharge to facility. Our objective was to investigate the joint effects between IHT and the presence of in-hospital delirium on the outcomes of LOS, discharge to a facility, and in-hospital mortality.

Methods: This was a single-center retrospective cohort study of 25,886 adult hospital admissions at a tertiary-care academic medical center. Staged multivariable logistic and linear regression models were used to evaluate the association between IHT status and the outcomes of discharge to a facility, LOS, and mortality while considering the joint impact of delirium. The joint effects of IHT status and delirium were evaluated by categorizing patients into one of four categories: emergency department (ED) admissions without delirium, ED admissions with delirium, IHT admissions without delirium, and IHT admissions with delirium. The primary outcomes were LOS, in-hospital mortality, and discharge disposition.

Results: The odds of discharge to a facility were 4.48 times higher in admissions through IHT with delirium when compared with ED admissions without delirium. IHT admissions with delirium had a 1.97-fold (95% confidence interval 1.88-2.06) longer LOS when compared with admission through the ED without delirium. Finally, admissions through IHT with delirium had 3.60 (95% confidence interval 2.36-5.49) times the odds of mortality when compared with admissions through the ED without delirium.

Conclusions: The relationship between IHT and delirium is complex, and patients with IHT combined with in-hospital delirium are at high risk of longer LOS, discharge to a facility, and mortality.