Delirium is characterized by a fluctuating level of awareness and cognition. It is frequently seen in patients hospitalized with strokes. Despite delirium being a temporary condition it can lead to worsened outcomes. 

We utilized Nationwide Readmissions Database (NRD) to identify AIS using appropriate ICD-9CM codes in primary diagnosis field and delirium was identified by appropriate ICD-9CM in secondary diagnosis field. Predictors to assess the association between baseline characteristics and 30-day readmission were analyzed using multivariable logistic regression model.

We identified 1958231 patients with hospitalizations for AIS between 2010-2014. Patients had an average age of 70.9 years, 48.3% were male and 51.7% female. 58738 (3%)of patients had a concurrent diagnosis of delirium. Patients with delirium were older (75.4 vs. 70.7 years; p<0.0001), and had a higher comorbidity index (p<0.0001). They were less likely to have received thrombolysis or mechanical thrombectomy (p<0.0001). Patients with delirium and AIS were less likely to be discharged home (42% vs. 63.4%; p<0.0001). The presence of delirium was also associated with a longer median length of stay (6 vs. 4 days; p<0.0001), and increased 30-day readmission (15.4% vs 11.8%; p<0.0001). Delirium in AIS patients increases 30-day readmission by 28% (OR 1.28, 95% CI, (1.24-1.33); p <0.0001). Etiologies of readmission were most commonly neurological (25.3%), with 12.8% being ischemic stroke. This was followed by readmission for infection (14.7%), kidney or urinary complications

(12.6%), pulmonary (10.3%), and cardiac causes (10.2%). Presence of delirium was associated with higher mortality rate compared to AIS alone (10.3 % vs 5%; p<0.0001).

The concurrent diagnosis of delirium during acute stroke hospitalization leads to markedly worse outcomes with increased rate of readmission and mortality. Protocols to prevent delirium should be implemented during hospitalizations for AIS.