Abstracts

Rationale:
Among hospital patients, seizures are common and have been associated with poor clinical outcomes. Little is known about the current prevalence of seizures amongst U.S. inpatients (IP) and emergency department (ED) outpatients and their characteristics. This study aimed to estimate the prevalence and distribution of seizures within the hospital setting, understand the patient demographics, clinical characteristics, and patient journey.
Method:
This retrospective observational study analyzed patients aged ≥18 years treated in hospital ED or IP setting between July 1, 2016 and December 31, 2019 using data from 860 U.S. hospitals included in the Premier Healthcare Database (PHD), a national hospital discharge database. Prevalence of seizures and distribution of seizures types (assessed via ICD-10 codes) and patient demographic and clinical characteristics were assessed. Patient journey was also assessed for the IP population with seizure diagnosis. Descriptive statistics were used to assess outcomes of interest.
Results:
A total of 72.4M ED outpatient visits (36.6M unique patients) and 24.9M IP admissions (16.5M unique patients) were analyzed. The prevalence of seizures in ED and IP was estimated to be 2.05% and 4.85%, respectively. Among the 1,359,891 unique patients (652,769 ED outpatients and 702,122 inpatients) with seizure diagnosis, mean age was 57.95±18.58 years, 50.6% were female, 70.3% were White, 72.2% were non-Hispanic, and 53.8% Medicare insured. The most common seizure type was unspecified (49.1%), followed by other (42.8%, including 38.5% with convulsion), generalized (4.4%), partial onset/focal (2.9%) and multiple types (0.8%). Among seizure-associated visits, seizure was the primary diagnosis for 42% of ED visits compared to 17% of IP admits. Among seizure inpatients, 31.6% had ICU/NCCU stay, 1.1% were intubated; the most common comorbidities were hypertension (62.9%), congestive heart failure (15.0%), cardiac arrhythmia (14.0%), and dementia (12.7%). In terms of patient journey, 71.7% of seizure inpatients were admitted through ED or trauma center as referred by physician (90.7%).  Approximately 25% of seizure inpatients were admitted directly to ICU ward, 6% were admitted to regular ward then admitted to ICU, and 69% were admitted to regular ward only. Less than 1% of seizure inpatients were discharged directly from ICU ward and majority as expired (45.1%). Fewer patients expired (5.5%) when discharged from regular ward. Top three primary diagnoses for ED outpatient visits with seizure as secondary diagnosis included syncope and collapse (10.8%), headache (4.2%), and alcohol abuse/dependence (4.0%); for inpatients with seizure as secondary diagnosis included sepsis (14.8%), alcohol abuse/dependence (5.1%), and pneumonia (4.3%).
Conclusion:
Seizure prevalence in ED and IP settings was higher than previously reported. Nearly a third of IP seizure patients had ICU stay and almost half of all seizures were unspecified. The overall in-hospital mortality rate among IP seizure patients is high.
Funding:
:UCB Pharma-sponsored