Prevalence, predictors, and prognosis of mortality among elderly stroke patients with convulsive status epilepticus in the United States

Abstract

BackgroundStroke is the most common cause of epilepsy in the elderly. However, despite the high mortality typically associated with convulsive status epilepticus (CSE), there is a dearth of nationwide data on the magnitude and association of CSE with mortality among hospitalized elderly with stroke in the United States. MethodsWe analyzed the 2006–2014 National Inpatient Sample (NIS) to identify elderly patients (65+ years) with a primary discharge diagnosis of stroke using the International Classification of Diseases, Ninth Revision-Clinical Modification (ICD-9-CM) codes 433.X1, 434.X1, 436, 430, 431, 432.0, 432.1, and 432.9. We examined a subgroup with a secondary discharge diagnosis of convulsive status epilepticus (ICD-9-CM: 345.3). We estimated the hospital mortality rate by CSE status and then evaluated the independent association of CSE and other key factors with mortality among hospitalized elderly with stroke. ResultsA total of 1220 elderly patients (0.14%) had a secondary discharge diagnosis of CSE. Inpatient mortality rate was 25.8% among those with CSE vs. 7.7% for non-CSE patients. CSE was independently associated with a 4-fold increased odds of in-hospital death. Increased age, medical comorbidities, weekend admissions, being a Medicare beneficiary, and hospitalization in large urban teaching hospitals were also independently associated with a greater likelihood of in-hospital death. The small number of events did not allow analysis by stroke subtypes. ConclusionWhile CSE occurs in just 14 of 10,000 hospitalized elderly stroke patients in the United States, it is associated with a 4-fold higher odds of in-hospital death.