Causes and Predictors of 30-Day Readmission in Elderly Patients With Delirium

To study 30-day readmission (30-DR) rate and predictors for readmission among elderly patients with delirium.

This was a retrospective observational cohort study of patients aged ≥65 years with discharge diagnosis of delirium identified from the Nationwide Readmission Database using common International Classification of Diseases, Ninth Revision, and Clinical Modification codes linked to delirium diagnosis. Multivariate logistic regression analyses were performed adjusting for stratified cluster design to identify patient/system-specific factors associated with 30-DR.

Overall, the 30-DR rate was 17% (7,140 of 42,655 weighted index admissions). The common causes of readmission were systemic diseases (43%), infections (27%), and neurologic diseases (18%). Compared with initial hospitalization, readmission costs were higher ($11,442 vs $10,350, p < 0.0001) with a longer length of stay (6.6 vs 6.1 days, p < 0.0001). Independent predictors of readmission included discharge against medical advice (odds ratio [OR] 1.8, p < 0.0034), length of stay (OR 1.3, p < 0.0001), and chronic systemic diseases (anemia, OR 2.4, p < 0.0001, chronic renal failure OR 1.4, p < 0.0001, congestive heart failure OR 1.3, p < 0.0001, lung disease OR 1.2, p < 0.0004, and liver disease OR 1.2, p < 0.03). Private insurance was associated with a lower risk of readmission (OR 0.78, p < 0.02).

The main predictors of readmission were chronic systemic diseases and discharge against medical advice. These data may help design directed clinical care pathways to optimize medical management and postdischarge care to reduce readmission rates.