title: Seizure Correlates with Prolonged Hospital Stay, Increased Costs, and Increased Mortality in Nontraumatic Subdural Hematoma.
abstract: BACKGROUND
  Nontraumatic subdural hematoma (NTSDH) is a common neurosurgical disease process, with mortality reported as high as 13%. Seizure has a known association with NTSDH, although patient outcomes have not previously been well studied in this population. The purpose of this study was to examine the relationship between in-hospital seizure and inpatient outcomes in NTSDH.
  
  
  METHODS
  Using the University HealthSystem Consortium (UHC) database, we performed a retrospective cohort study of adults with a principal diagnosis of NTSDH (International Classification of Diseases, Ninth Revision code 43.21) between 2011 and 2015. Patients with in-hospital seizure (International Classification of Diseases, Ninth Revision codes 34500-34591, 78033, 78039) were compared with those without. Patients with a history of seizure before arrival were excluded. Patient demographics, hospital length of stay (LOS), intensive care unit stay, in-hospital mortality, and direct costs were recorded.
  
  
  RESULTS
  A total 16,928 patients with NTSDH were identified. Mean age was 69.2 years, and 64.7% were male. In-hospital seizure was documented in 744 (4.40%) patients. Hospital LOS was 17.64 days in patients with seizure and 6.26 days in those without (P < 0.0001). Mean intensive care unit stay increased from 3.36 days without seizure to 9.36 days with seizure. In-hospital mortality was 9.19% in patients without seizure and 16.13% in those with seizure (P < 0.0001). Direct costs were $12,781 in patients without seizure and $38,110 in those with seizure (P < 0.0001).
  
  
  CONCLUSIONS
  Seizure in patients with NTSDH correlates with significantly increased total LOS and increased mortality. Direct costs are similarly increased. Further studies accounting for effects of illness severity are necessary to validate these results.
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Jacob R
authors.initials: JR
authors.lastname: Joseph
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Brandon W
authors.initials: BW
authors.lastname: Smith
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Williamson
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA. Electronic address: ppark@med.umich.edu.
authors.forename: Paul
authors.initials: P
authors.lastname: Park
mesh_terms: D000368:Aged; D003422:Critical Care / Q000191:economics*; D005260:Female; D006408:Hematoma, Subdural / Q000453:epidemiology / Q000401:mortality / Q000601:surgery; D017721:Hospital Costs; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay / Q000191:economics*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D012640:Seizures / Q000191:economics / Q000453:epidemiology*
keywords: Epilepsy; Nontraumatic; Seizure; Subdural hematoma