Trends in Status Epilepticus-Related Hospitalizations and Mortality: Redefined in US Practice Over Time

Abstract

Importance: Status epilepticus is a common neurologic emergency with significant associated morbidity, mortality, and health care costs, yet limited data exist detailing trends in status epilepticus-related hospitalizations and mortality.

Objective: To examine trends in status epilepticus-related hospitalizations and mortality.

Design, setting, and participants: We performed 2 retrospective serial cross-sectional studies including 408 304 status epilepticus-related hospital visits using generalizable national data from January 1, 1999, to December 31, 2010, from the Centers for Disease Control and Prevention and the Nationwide Inpatient Sample. Centers for Disease Control and Prevention death certificate data, using International Statistical Classification of Diseases, Tenth Revision, codes, were used to determine nonstandardized and age-standardized rates of status epilepticus as the underlying cause of death in the United States. Data from the Nationwide Inpatient Sample were used to estimate population-standardized status epilepticus-related hospitalization rates using International Statistical Classification of Diseases, Ninth Revision, codes.

Main outcomes and measures: Status epilepticus-related hospitalizations were categorized by whether status epilepticus was the principal diagnosis, whether the patient was intubated, and by primary insurance type. Temporal trends were tested using Poisson regression and summarized with quarterly incident rate ratios.

Results: In 2010, status epilepticus was the reported underlying cause of death in 613 deaths (approximately 2 per 1 000 000 persons). Age-standardized status epilepticus-related mortality per 1 000 000 persons increased by only 5.6% (incident rate ratio, 1.004; 95% CI, 1.002-1.006) from 1.79 in 1999 to 1.89 in 2010, while population-standardized hospitalizations for status epilepticus per 100 000 persons increased by 56.4% (incident rate ratio, 1.013; 95% CI, 1.012-1.013) from 8.86 in 1999 to 13.86 in 2010. The largest increase (181.6%; incident rate ratio, 1.030; 95% CI, 1.029-1.030) was seen among intubated patients with nonprincipal diagnoses of status epilepticus. Among varied insurance providers, the largest increase (81.3%) was seen in Medicare patients.

Conclusions and relevance: A disconnect exists between the relatively stable status epilepticus-related mortality and the marked increase in status epilepticus hospitalizations, likely reflecting an increase in status epilepticus diagnoses through improved diagnostic sensitivity and changes in billing and coding. The definition and general approach to status epilepticus, including resource use, should evolve with these changing epidemiologic trends.