Influence of a Comorbid Diagnosis of Seizure on 30-Day Readmission Rates Following Hospitalization for an Index Stroke

Objective: To examine the association of a comorbid seizure diagnosis with early hospital readmission rates following an index hospitalization for stroke in the United States. Methods: Retrospective analysis of the 2014 National Readmission Database. The study population included adult patients (age >18 years old) with stroke, identified using the International Classification of Disease Ninth Revision, Clinical Modification (ICD-9-CM) codes 433.X1, 434.X1, and 436 for ischemic stroke as well as 430, 431, 432.0, 432.1, and 432.9 for hemorrhagic stroke. A subgroup of patients with a secondary discharge diagnosis of seizures was identified using the ICD-9-CM codes 780.39 and 345.X. We computed all-cause 30-day readmission rates for all strokes and by stroke type (ischemic versus hemorrhagic). Finally, we used a multivariable logistic regression model to examine the independent association between seizure and readmission by stroke type. Results: Of 271,148 stroke patients, 6.3% (16,970) had a secondary discharge diagnosis of seizures including 5.0% (11,562) of patients with ischemic stroke and 13.4% (5,409) with hemorrhagic stroke. Overall readmission rate for stroke patients was 11.9% (hemorrhagic stroke: 14.2% versus ischemic strokes: 11.6%). Thirty-day readmission rate was higher in patients with seizures for all strokes (15.6% versus 11.7%, P value <.001), ischemic strokes (15.0% versus11.4%, P value <.001), and hemorrhagic strokes (16.7% versus 13.8%, P value <.001). After adjusting for several patient-specific and healthcare system-specific confounders, hospitalized stroke patients with comorbid seizure diagnosis were more likely than those without seizures to be readmitted within 30 days (OR: 1.20, 95% CI: 1.14-1.25). Conclusion: The presence of a comorbid diagnosis of seizure disorder in a hospitalized stroke patient significantly raises the occurrence of early hospital readmission in the United States.